Mercedes ML550 M278 Bi-Turbo V8 Engine Teardown. Unavoidable Failure?!
For parts Email us at Importapartsales@gmail.com or visit www.Importapart.com!
Here's weekly dose of your catastrophic engine forensics! Every week you can find a new teardown of some abused, misused and/or poorly designed engine. I've got over 150 videos of failed engine teardowns on this channel.
This week's teardown is a Mercedes Benz M278. A 4.7L DOHC Bi-Turbo DI V8. These engines make 400-450hp and come in midsized and larger cars and SUV's with the 550 designation starting around 2011. This particular engine is from a 2013 ML550 and is a core return from a local salvage yard. As such, I don't have information like mileage or suspected failure.
In this video I tear this engine down complete and try to figure out what went wrong and why, as well as what parts I can salvage to resell. These engines have a LOT of pricey parts so they are quite lucrative for the shop but those parts have to be good.
Why am I doing this? I own and run a full service auto salvage business called Importapart, and part of our model includes dismantling blown and bad engines to reclaim the good, sellable parts from them and recycle the rest. We do not rebuild engines, merely supply parts to those that do.
I really hope you enjoyed this video. As always, I love all of the comments, feedback and even the criticism. Catch you on the next one!
-Eric
I started cutting oil filters open when I changed companies and they did not do oil analysis. One thing to pass on to every one: change your 1st oil change no more than 1000 miles, every analysis that came back was laden with dirt, brass, iron and other things (all which enter during assembly and as everything wears in) and the 2nd analysis would always come back nearly immaculate! So since newer engines run tighter specs and thinner oil. Do yourself a favor, drop the oil early!
Yep that’s what I do…
Did 500 on my new truck for the first change.
A KZhead channel called FortNine did an analysis on motorcycle manufacturers with a machine that scanned for particulates in oil using first service samples The Chinese manufacturers broke the machine from the amount of rubbish left over from machining Royal Enfield India was cleaner than every other manufacturer by multiple factors
I dropped mine on my 89 L98 after the first rebuild at 400...Looked good no metal and no trash..
Good advice but I won’t need it because I refuse to buy a new car 😊
I like that those exhaust headers look like Fritz just beat the hell out of them with a hammer until they fit but in reality they spent countless hours of engineering and testing to get them right
I came here looking for this comment. I thought for sure the exhaust were beat to hell. Interesting that they were engineered like that!
Pretty sure that's a form of engineering
@@ZachSteinform engineering
Hydraulic forming.
You'd be amazed, and maybe a bit scared, of what they can do with computer modeling these days... o!O
Seeing these DI only engines makes me glad that my car has dual injection. Best of both worlds for emissions, efficiency, and clean valves
The best or nothing! Funny that toyota knows better than all the other companies, they have port and direct injection. Thought i heard some of the lexus models were direct injection only but at least they learned from mistakes and fixed them going forward.
I read it on mb forum, just want to post here so people can prevent this from happening (applicable for m276, m278, m157 owner). The oil pump on this thing is a two stage oil pump and it has a solenoid switch can switch between low pressure and normal pressure mode. (Low pressure mode is for fuel saving...) Sometimes the solenoid getting stuck because the dirt inside engine oil and the engine will stay in low oil pressure mode then this happens. Fix is quite simple and cost $0, you just unplug the plug of that solenoid from the oil pan. No CEL, no big code, the only code is a hidden code that will literally cause nothing, even the MB bulletin ask dealer don't fix this code, even if it's within warranty.
Where is this solenoid and plug located exactly?
That’s not the reason why this fatal damage occurs. The coating of the cylinder walls is the problem. That’s why in 2016 these engines have been updated to steel cylinder liners without Silitec coating. Unfortunately only the 4,7 liter engine. Not the 5,5 Liter AMG engines.
Cam caps integrated into the valve covers sounds just like the sort of semi-brilliant but horribly expensive idea that a German engineer would think up, there was a time when Mercedes was renown for their near bullet-proof engineering and impeccable built quality and you paid a premium price for a car that would likely last longer than you would with proper care. Now it seems like just another outright money grab based on brand snobbery.
Now they're built to a price point. Gotta cut costs somewhere to pay for all that glitzy in cabin tech.
Mercedes just be throwing shit together now. Bmw too. And the fanboys still think they're better than an American v8😂
I still say that the 1980s and early 1990s were the pinnacle of most German cars. Compared to current BMWs, my 1989 BMW 635CSi is as reliable as a Honda
Crosley ran their overhead cam in the aluminum alloy cam pillow blocks back in the 1940's/50's. Crosley made no excuses, it was simply done to save costs, nothing else. No one has ever compared Crosley to Mercedes-Benz until now!
their blocks were stamped steal. Overheat one of those engines and it was curtains.@@geoffmorgan6059
Literally every time Eric said “Bore score” My brain immediately autocompleted it to “Bore score and seven years ago”
I like the way your brain works
Since finding kevin Samuel's I find myself asking modern women what's your bore score wh@re? I'm single.
I have a toddler that loves these videos. It has become a Sunday evening tradition. Thanks for keeping them going.
You'll have to buy him a used water pump now.
My daughter would do the same thing! She's more of a gamer now
The water pump and timing parts gags are gold.
I was ctfu at the water pump bit. I love how creative he gets
I am waiting for him to get a really old, rare engine and actually keeping one to sell.
I think that he kept the one from the expensive Dodge V10. EDIT - Viper?
Somanyteapots we all need more Eric comedy!!! I think it is one of the best KZhead channels.
@@russellstyles5381 and the Prius water pump
M278 is a thing of beauty, they get close to 28+ mpg all day for a 400 hp. V8 , they just needed port injection secondary to keep inlets clean.
Soooo my car has the same engine. And just started missing on 1 and 2 precisely where those 2 really bad pistons are located 😂. Thanks for the video. I'm going to go cry myself to sleep now lol
Borescope time????
Engine Restore
@@m-c-m- ya we will see. I just bought a camera to take a peek at the cylinders. Just waiting for warmer weather now.
@@JohnSmith-yv6eq ya for sure. I just left it alone for the winter. We will check it out soon.
How many kms?
Was expecting to see the water pump launched into the scrap bin and then to see the box being run over by the truck was even better. 😂
No love for water pumps….
Do you know how many "Car Poor" ghetto dwellers in Salvage Title "Benz" cars who would love to have that perfectly functional water pump? Seriously, how are they supposed to go visit their kids (once the talk show validates paternity) if they can not afford a water pump? @@concernedcitizen780
That pump is way over- engineered and expensive. He kept it for resell
I believe the mini oil pump is for scavenging oil from the turbos.
I had a ML550 with this engine. It was recalled for a intake manifold within the first 2500 miles I had it. Fletcher Jones in Vegas did the replacement and screwed things up. They got some of the vacuum lines hooked up incorrect and caused the tumble flap to activate and cause lots of noise. The first time they said I put bad gas in it and charged me for the service. I did not even make it 50 miles and the sound came back again. They had it another cou-ple of weeks and said everything was fine. Again after picking it up it started making the noise again. I drove it home 600 miles and took it to my dealer in Idaho. They found the misrouted vacuum lines and I drove it for 130,000 miles of trouble free driving. Only a small leak out of the rear main seal when I traded it in.
When I used to work for a European specialty shop, MB were my favorite to work on because, out of all the German makes, they seemed to have at least some concern for serviceability. Not anymore. With those nut holders over the exhaust manifold nuts, I cannot imagine being able to replace the turbos with the engine in the vehicle. That is a consideration because turbos on GDI engines designed for fuel economy, emissions and throttle response ALWAYS have turbo failures. Always. The turbos are always undersized (for throttle response) and also have a lava hot catalytic converter sitting next to them. With all the induction piping, even something like a belt change looks like a multi-hour job.
Those issues occur on turbos for euro diesels too, having a extremely hot dpf during a regen with a Diesel oxidation catalyst close enough to bake the exhaust turbine is not very good for them. My passat TDI snapped the exhaust turbine shaft at about 140k, no more dpf to worry about though
In regards to the head bolts, Welcome to Torque to Yield fasteners. When you torque a fastener to it's Yield Point you have insured that fastener has no "reserve strength" and a small additional load can snap it like a dry twig.
Yeah, I was wondering if that was what was going on. Thanks for confirming.
they need to be nearly as strong as the aluminum heads. So a soft steel to prevent stripping threads
275K subscribers, you must be doing something right. I wonder how many of us are not mechanics but are still fascinated by these teardowns? I saw the box of snack packs in the background and for some reason instantly wanted one, lol.
You should show us how do you get a broken bolt like that one. Your videos are great.
You don't, besides the block is wasted. You can't bore it oversize, it's got Nikasil coated bore.
@@brianallen9810You can sleeve it i think. I believe Taso mercedes guy has video on it.
I was wondering the same. Jeez breaking head bolts like that is crazy!@@brianallen9810
Its always cool to see you teardown Benz engines as i work at a Mercedes dealer. Seeing things than come in day to day but fully torn down is super neat. If possible, an M274, M260, or an M132 would be some interesting ones to teardown. Much love, Eric!
To avoid breaking the head bolts you may want to try this. When you hear the first pop quit turning. Remove your socket and strike the bolt rather hard on the head with a drift or directly with a hammer. Put the socket back on and remove the bolt.
That's brilliant.
who taught you these skills, they are unbelievable !
I love how symmetrical it looks!
Perfect way to cap off my night with one of these uploads. Thanks man.
Thank you for all your great videos. I watch more KZhead then I do regular TV. I've learned a lot about different engines. Love it!!
Another great video Eric. The water pump bit at end was pure frosting. It never gets old!
Hi Eric, I always enjoy your videos, whether they be engine teardowns, working on your own cars, or trying to get vehicles running that you just brought onto the yard. I have learned a wealth of information about internal combustion engines from your teardowns. I've always know the importance of regular maintenance on vehicles, its fascinating to see how the lack of regular maintenance can destroy a high quality, reliable and well engineered engine. One thing I'd love to see is a compilation video of cracking cam-cap bolts, rod bolts, head bolts, and main bearing bolts. I absolutely love the sounds and I find them strangely soothing. But I'm just kind of a nut-case that way. Keep providing this fantastic content. The great thing is that it seems there's no shortage of source material!!
It’s good when the head bolts pop and crackle, but it’s bad when they snap.
Just rice crispies
The amount of deposits on the back of the valves is just incredible. In flowing heads that type of restriction would be catastrophic for a naturally aspirated engine. Since this is a turbo perhaps it is not as bad. I was also shocked that the oil pump was a vane type pump. The flow and pressure requirement must be rather large to require a vane approach.
Those twin turbos are probably pretty thirsty as far as oil is concerned.
Merc has had a fairly strong preference for vane-style oil pumps for quite a while, even on very low-power (by their standards) engines.
Is a direct injection problem, happens to all.
It's highly detrimental in forced induction. Carbon coking is a huge problem with GDI engines, and one of the reasons why some companies opted for a multi injection system.
Junk on the valves will cause airflow issues, whether na or boosted to 20psi.
Great editing as always. Thanks for another great tear down.
Good to see the Garrett/Honeywell turbos hang in there. They have a good reputation and seem to be better than pretty much all of the competition in terms of longevity.
I have this engine with a tune on it and 225,000 miles. Original turbos still holding up perfect
I can think of a few reasons for the pistons damage. Over heating is the first that comes to mind. Second is too tight of tolerance. The initial build should have had more clearance between piston and bore. Third would be improper taper on the pistons. Fourth would be the pistons alloy. I made a few pistons. We had two different alloys for pistons. One was for standard pistons and another for high performance pistons. Standard pistons, for the most part, used hss and carbide to machine the pistons. The high performance pistons had to be machined with diamond tooling. Hot running engines, such as the Ford 351 and AMC 360, we had special tapers and finishes for the skirt. From what I could see, the pistons didn't have the high performance alloy I had machined. I also did not see the special finish that I had put on hot running engines. Given that this is a high performance engine, I would expect at least one of those attributes. In my opinion, this is a poorly engineered engine that allows the piston to expand and transfer piston material to the walls of the cylinder.
Another Great tear down Eric... Please continue
Can we just stop for a moment and appreciate that this engine had 8 cylinders, two turbos, an intercooler hidden under the intake and makes 400+hp, and its small enough that you can fit your arms around it? This little motor, has and does all that, and is smol.
Dude this is a huge engine.
@@pearldrums92 It is, and yet its small enough that, if it didnt weigh a million pounds, you could curl it to your chest and walk around with it. There are physically larger gas V8s, and inline 6 engines for that matter, with less complexity that you could not do the same with.
Ya but extremely over engineered and not well. You could make a twin turbo ls or lt that is way smaller probably twice as powerful and last twice as long. Sometimes the most simple thing is the best thing.
400HP is pathetic
@@Mister_Durden 400hp is more than 90% of people need. Most couldn't handle using all of 400hp without wrecking.
Perhaps the leaf was the root cause of the oiling problem, clogging the branches to the bearings and rings. Tree rings.
I think you're barking up the wrong tree.....
My dads Saturn has eaten many a leaf and is still doin just fine at 445k
Good evening Eric. Just watching you try to turn over the engine is getting me hopeful for some malice. What drastically deed will you do tonight to the poor water pump? I just cannot wait. 😆
I have a '14 GL450 with this engine. I'm aware of the bore scoring, and mine does use a little bit of oil, but runs perfect, no misfires or funny business like that. I have a lift in my garage with full intention of pulling the engine whenever it decides it is time. Love the vehicle. The ONE thing that worries the hell out of me is the fact that you've now broken THREE head bolts on M278s. If I broke one that would either be a machine shop handover or a junkyard handover. I'm not even sure how I would go about extracting a broken bolt that far down in the block. When my time comes though I'm sure going to be using this video for a reference!
You could probably get them out no problem if you took your time and did it way more slow & patiently. I think it was a GM 4.3 6 cyl that I saw disassembled that had very hard to remove head bolts. The trick was to slightly tap w\ hammer & punch and turn like a quarter turn at a time alternating hitting & turning. It's shocking the threads back a little each time so they don't stick and snap. Spraying pb blaster or whatever down the thread holes days ahead of time should help too. Also, I think once the bolt snaps off, all the tension is gone(theres no head left), so just a SHARP left hand drill will walk it right out of the recessed hole. It's not like it's rusted in there from sitting for years in the elements. 👍🏻👌🏻🛠️🔩🔧🤔🍻
I dont know if this works but ive been told. If you ever get a chance to try this, please do. So in this video youll notice there are usually 2 clicks and when you hear the first click, just stop. Take off the tool, and smack it with a hammer kinda hard but not too much. Then continue to take it out. Its worth a shot
@@tdotw77 dead right a leftie should draw it out.
Just found this channel. Addictive. Some things just draw me in. For example car detailing. This, most definitely does
damned that thing is a *beast*. Imagine working on that in the car! And what you were talking about at about 8:50 is called "Safety Wire" - something all us aircraft wrenches know all too well.
Brett is quite the thespian. 👏 Taryl Dactyl and his crew at the Grass Rats Garage are still number #1 but you guys are making a strong push.
Thanks for doing a teardown on a M278! These engines are known for premature piston/bore wear, but only in certain VIN/Engine number ranges. Only some have this issue from 2014+.
Any idea if this affects 2017's? We have a GLS 550 with this engine. Currently has 50k miles.
I’ve seen all years M278’s have premature wear on cylinder bore, camshaft/ rocker arm & rod bearing’s. Not too mention the issues of camshaft position sensors pumping oil into the engine wire harness. These engines are junk by 90k. Replacement cost is $34k.
@@WRCWRX Well, while I don't like to argue online, my M278 is sitting at 112k and only burns about 1qt every 6k (my OCI) and has been doing that since 20k miles. But I have an extended warranty, just in case.
@@AZMTBMB revised the block in early CY 2015 with different bore surface material. Your 2017 should be fine.
I believe silitec cylinder wall linings were in the earlier versions, then they went to nanoslide wall linings.
Gotta love Saturday night!! Hope you had a good thanksgiving Eric, and a happy holidays!!
Those intake valves..... it's like DI problems were built into the ownership experience. MPI on Mercs from the early 2000's was great, the old 5 speed auto was great too. It's like E500's might outlive E550's altogether.
Now imagine having a KIA direct injected engine. lol
NA 550s last a long time if they're taken care of. The M273 is an excellent motor. Outside of very early production that had an issue with a timing chain idler, they don't have any big issues and make significantly more power than M113s. Good old port injection too so no intake valve issues.
I can’t count how many E500s I’ve seen with 200k+ miles my own included. My M273 made it over 200k but that was also a NA engine. I’m seeing these twin turbo ones blowing up left and right lately
More mercedes engines !!! Please ! Love seeing someone else other than me do this lol . Hopefully you get a m274? As a mercedes tech overall these are pretty solid there were a decent amount of bad ones but mb is taking care of it surprisingly, check heads and exhaust valves ! Best guess is burnt valve seat or valve and still drove it with the misfire caused further damage leading to scoring .
What actually causes the bore scoring? How do you get sideways forces to push the piston into the bores? Or is it thermal somehow? Like the bores constrict in that direction when it gets hot?? Is it a design flaw of some kind?
M113!
@@gorak9000Wear metals in oil likely caused the scoring.
But its almost every cylinder... in the same area...i hear what you are saying, but as an engineer, for the result of the burnt valve to be consistent - without 6 cylinders worth of burnt valves (unlikely), there is more likely a design flaw Or weakness. .... whereas less then perfect maintenace .. or less than perfect manufacturing process leads to failure of the weak link... cylinder walls in a very specific area...and the resultant fragment eventually taking the engine out..
I’m hoping to see him tear down an M119, M113 or M113k
I worked on MB from 1973 until 2007 when I switched to semiconductor FAB work. I am SOOOO happy I dont have to deal with that junk anymore. The factory rep told me it was a high tech rocket that couldnt get off the lot,he was right. I ma making more now than I ever did at a dealership,and I go home clean.
German cars=junk. Toyota and Lexus showed up the krauts
i worked for mb from 95 to 08. so glad to get the hell out of the dealership. what a horrible company to work for.
Hey, i did something pretty similar! Worked in auto shops for a decade, then moved to semiconductors. Been to a few fabs now, very interesting career.
These vids are the best part of my week
Exxxxxxcellent work, it was very hard but you did everything. There are lots of details and pieces. Thanks for sharing ⭐️⭐️⭐️⭐️⭐️
For a modern German engine, that one didn’t look too complicated. But the propensity for the head bolts to snap off is scary!
Did you notice it was the same bolt in the same position on both sides too? Seems like a design flaw or something. That and what causes the bore score? Is that also some kind of design flaw with the casting? It seems like it could be thermal related somehow.
The head bolts are an issue with all mercedes v8’s. Most everyone that i know, including myself has had head studs installed in the place of the bolts.
@@gorak9000 I think a big part of that scoring is from carbon build up on and around the pistons and combustion chambers. I think it's not a coincidence that engine is direct injection. A lot of the carbon buildup gets squished around by the small piston to valve clearance, including around the sides and skirt, the only other thing I can think of that would cause that type of damage is piston slap.
How would you remove the broken head bolts??
? that doesn't happen...
Just a few thoughts on this, other than that I think the engine looks really cool fully dressed. :) 1. I'm reasonably sure that the back 2 cylinders had cleaner valves than the rest because the valve guides were leaking, and the small amount of oil flushing the area kept the valves cleaner and the spark plugs dirtier. 2. The reason the crank and cams were OK even though there was metal in the oil was that the metal was all aluminum with no steel in it; aluminum is so much softer than steel that it can't scratch it very effectively. Add in the very small particle size and its more of a polish than an abrasive. 3. I strongly believe this engine was overheated somehow. Not apocalyptically, but enough to distort the cylinders and pistons so they didn't have the clearances they need. Also enough to get the cylinder head bolts really good and stuck. The idea expressed elsewhere in this comments section to give the bolts a good whack with a hammer and punch between the first click and the second groan (to relieve some of the internal tension) is actually brilliant.
I’m 99.0% sure this engine is dead from a tuner/performance aspect. This engine was prolly tuned by someone who didn’t know wtf they was doing, and prolly had the pop/crackle tune. Definitely looks like a slightly lean/detonation ordeal, somthing in the tune was beating the piston. Have seen this in a few of these engines, and a lot of the amg 63s that have had the turbo upgrade and tune! Have never seen a Benz tuned/upgraded turbo engine come in with these type failures. We build these bastards, and do some crazy stuff with these things. And they make crazy power, reliably if your bank accounts big enough
The m156 6.2 v8 are the ones with lots of issues! But we bullet proof these things, with good custom made in-house billet Replacemnets, my personal, daily driver is a rods piston, m156 with 60k miles on a inhouse built engine. Around the 700ish wheel hp
@@bigwater52What is your shop, any build thread on your m156? I have researched m156 and m157, I think i want a w212 m156 car. Yes they have head bolts, vvt wear, cam and bucket wear, intake leak. But doesn't look so bad compared to m157 plastic parts, cylinder scoring, and DI issues/costs. What did you do to your m156? They're beastly stock, around 500hp, i heard sls m159 is over 600hp na. The weistec superchargers look sweet.
@@bigwater52 Doubtful in an ML550. My guess is excessive idling in cold climate. The previous M273 had the same issue. MB engines are total garbage anymore and good for 100k tops before the problems are likely to start.
I love your channel. At some point in the future can you spend a minute or two on how a high pressure fuel pump works. I can't quite figure it out. Many thanks for your love of this channel
Great video. Love your channel. Thanks for the content.
Never ceases to amaze me how different manufacturers build different engines to solve the same problem. The contrast between this merc and an ls3 is huge, but basically put up the same performance numbers. I'll take simple over complex any day 😊
It's not all performance. All manufacturers and their RND is working with the same tools but with different goals. This motor happens to be the answer to the question that no car enthusiast will ever ask (efficiency, economy, emissions, smooth power etc)
Yeah when he mentioned the horsepower I was blown away. Funny thing is that the ls3 or lt1 will burn less fuel doing it. It's hard to appreciate any advantage to this thing.
I would imagine with simple tuning this motor would have a much higher headroom in terms of power. I own an Ls3 powered car and I love it- but again I’d assume this thing could make 550+ with tuning and fuel. Ls3 makes 450 to the crank maybe with fuel and tuning.
@@pearldrums92 yeah and this thing is probably super efficient too.
@@pearldrums92 and it probably makes more power then they will admit. power is expensive and kill sales and profit
Great Video as always! My last Mercedes was a CL55 with a 113K motor that made it > 250K Miles with no issues. Now I have an M278 and am on my 4th set of turbo coolant pipes, bad tensioners, bad cam adjusters, constant check-engine light, leaking intercooler circuit, bad heater circuit, oil in the ECU and more antifreeze leaks than I care to list. I will not be giving the hot-vee engines a chance.
M113k for life for me. I stay away from these newer twin turbo V8s. I’d even take an M156 over one of these all day
Love the vids keep’’em coming
Great video and a great water pump skit at the end! Cheers.
The best part of Saturday night.
I had a 2012 CLS500 (AU) with the M278, no problems, but sold at about 60K miles. We now have a 2015 CLS63S with the M157. One potential issue is oil wicking up from the cam sensors, solved by checking and replacing them. Its done about 45k miles. No issues as yet. No tuning, no thrashing until warmed up. However, what a complex engine. They do also get very warm with the two turbos. You'd think manufacturers might have made a little progress in design and maintainability by now. That's the key insight from this.
Steel sleeves, and pistons would do wonders to correct this mess. I still prefer older Iron. It's just simpler to care for.
I love your videos, thank you for making them
I had a 2014 E550 Coupe that had that engine in it. Loved that car, it was fast and luxurious and it looked good.
Great video! Just curious, how long did this video take you to film and complete this tear down?
I had a E550 with this engine. They seem way more powerful than the 402HP there rated for. Car and driver ran a 12.8 @118 mph 1/4 mile in a 2012 E550 (4400 LB car.) It's all about the torque.
they make around 440-450 crank hp
The same appearing engine was rated higher--449 HP if my memory serves-- in the S class. But I agree, it feels enormously powerful with fabulous low end torque. It revs very well, but very seldom needs to.
Those hydro formed manifolds are beautiful.
Loved the water pump routine!
What a beast of an engine!
OMG that head bolt sequence was hilarious...good good good BAD good xD Looks like they designed that block to be non-serviceable since 1 head bolt per side snaps deep down in the hole guaranteed!
The bolts are bad, but you'd have to resleeve the engine, that would cost a fortune... not that the replacement engines don't lol
@@I_Do_Cars It's crazy that bore scoring led to this engine failure...would think they perfected cylinder and piston basic design decades ago...especially on something so high-performance and expensive lol!
Apparently they went to iron spray cylinder linings in 2015@@PineHollowAutoDiagnostics
You do a nice autopsy, I always learn something.
Love to see you tear down an AMG M178 engine.
Another interesting video. Sad that these engines have such terrible issues. They are very expensive.
They don't have this issue, it's an anomaly, if you want catastrophic failures watch BMW engine tear downs, M5's self-destructed on a regular basis.
Most issues arise due to lack of maintenance, a lot of people buy these cars, then realize they can't afford the insurance, the note, AND the upkeep, guess which gets overlooked.
@@shaggyduderthis engine looks relatively low mile considering how clean the turbos are. Maintenance or no maintenance, most modern German engines are disposable garbage. Best just to lease and toss…
These engines actually very very reliable except few small but rtareded. The main problem with them is 1. extended oil change intervals, this alone creates so many of M278/M157s problems its mind boggling.
Lack of maintenance (a common garden variety issue in some parts of the world) is the issue (terrible) here. Feed the engine right, and it's gonna last.
It'd be interesting to put a torque wrench on the head bolts and see how tight they are.
They snap off because they didn't use anti-seize at the factory ( they're threaded into aluminium ) or have them cadmium plated.
Pretty steady quality, too. On both heads the bolt that snaps is the same position and seems to snap from the same spot.
Breakaway torque and bolt tension aren't always related. Any fastener with thread lock, rust, galled threads or galvanic corrosion will have much higher breakaway torque than normal.
Another engine that is too complicated IMHO. Great job on the teardown. Your closing segment- priceless.
All engines are too complicated these days. Need to get all the emissions crap off them and they would be much better.
Thank you for this really interesting video. The engines seem so beautiful to look at, but the bore score problem is so ugly.
Bore scoring is an issue on some modern Porsche's when the engine is driven hard while still COLD. Great video!
yes you hit the nail on the head .
@@rodgoodahh really that was a theory I thought of. Owners just starting and leaving without warming up first.
From what I've seen, starting and leaving is preferred, as driving heats up the oil and coolant faster than letting it idle. You just don't want to start it, drive off, and immediately romp on it while still cold.
@@michaelhughes7513 Yup. Drive gently, staying below 3,000rpm until the engine is fully up to temperature and all the engine tolerances are as they were intended. THEN you can hoon it. Showing off from cold kills more high performance engines than anything else - maybe not immediately, but it shortens their service life dramatically. Driving like a granny may not be as glamorous as leaving with a roar of power & a cloud of tire smoke, but it's a heckuvalot cheaper in the long run.
I had the earlier ml 55 amg…..a spring broke on the throttle body……it started accelerating without control. I was just reaching to pop it into neutral and blow the engine when it finally dropped back to idle. Off to the Mercedes dealer i went after i discovered what the problem was. $900 dollars later i picked up the “repaired” car. Opened the hood, checked the spring (still broken) and went back in to deal with them……sold the car that week. It was my LAST MERCEDES. What can of worms those things are.
they sound like horrible cars
That ending was the best ever, thanks! Dave J
Love these videos, you’re having fun too.
Looks like a Tank Engine.
Gotta love the Germans!
What a coincidence! That's the first thought that entered my mind.
Merc does make engines for big farm equipment like class corn cutting chopper with over 800hp and over 2000tq And some Lori too
Guess you've never done a water pump on a three point eight nineteen eighty eight camaro, cause they have three Different bolt sizes and two are metric and one is standard
My God 400 hp for that monstrosity ?? That not much power for all that shi*.
The more I watch this channel, the more I swear off Mercedes and BMWs. I'd rather have a Chrysler.
Great tear down! Any chance you will do a Mercedes C or GLC 300 4-cylinder any time soon?
I love the SOLD water pump at the end
The part of the oil pump that you didn't know what it was, is the scavenge pump for the turbo oil return.
So sucking in the foamy turbo exit oil and squirting it where?... onto the windage tray?....... to lose the entrained air before it circulates back to the main pump via the sump?
Considering both broken head bolts being in the same position, I wonder if that is a problem with the automated torque tool used to make up the head bolts in manufacturing?
Yeah, I noticed that too - same bolt in same position on both sides... really makes you go "hmmmm....."
I think it was a temperature issue. All the scored cylinders are in the middle and the outside cylinders are fine, both broken bolts also in the middle cylinders. Most likely this engine ran hot, really hot, from lack of oil or coolant or just being redlined hard all the time. The middle pistons overheated, expanded too much and damaged the bores, the middle bolts were stretched. The cylinders at each end cool faster so they survived.
These were the bolts that sit behind the exhaust side of the turbos. So that area is simply hotter, than any other place.
@@BigUriel I felt like this engine suffered heat issues, too.
Loved the water pump bit!😂
Great video. That sure was a nice mallet you used.
I would redesign some of this engine,change that direct injection back to a port type or a combination of both types of injection,the valve cover/cam journal needs more webbing with oil galleries and maybe brass guides on the floating lands and this could be a very good V8 with double overhead cam valve train and twin turbos that with a non Cletus McFarland tune this thing would provide huge power with high mileage reliability.Breaker bar the head bolts loose,then tighten them back down and by the time you get to that head bolts that breaks,it won’t. Great video thanks for sharing.
I'm not impressed. Only 400 hp with twin turbos, DOHC, direct injection ect? My simple 351 Cleveland powered Mustang Mach one has 330 hp with pushrods and a simple Motorcraft 4V. Ridiculous. And my Mustang still runs after 50+ years and 1/4 the parts. A modern lawnmower has more tech than the Cleveland.
@@TheBandit7613 And do you think your 351 would meet any global emissions laws of the last 30 years?
@@MrPabsUk Not late model emissions. I don't think 73' needs emissions.
Your head bolt suggestion is a pro trick!!! Breaking the outer head bolts starts to put tension on the remaining inner ones so that it takes more torque to turn them.
I work at an independent mercedes shop and we regularly see a couple of these 278 engines come in with a customer complaint of knocking noise, you can hear them knock from underneath the car and then run a compression test using the mercedes scan tool and find them running low on compression, have seen a couple with this knocking noise running for 30k miles after we told them the cylinder walls are scored and needed an engine, so far i’ve only seen one engine that was scored so bad it was a dead misfire 28:18
what design flaw would cause cylinder scoring? Are the skirts too short?
@@aimless-driftergerman engineering.
@@aimless-drifterprobably overheated.
@@haydenh6339on an 30k mile engine?😂
@@warriorplutotrent3827 who said it had 30k? Mileage unknown in video. This happens often when the plastic turbo lines break and dumb customers keeps driving it.
as usual Excellent video
Thank you so much for this video - I have had eight Benzes and my GL450 2014 is easily my least favorite. This engine is so weird and designed to fail it gives me anxiety. I replaced the turbo cooler lines with the engine in the car and it took forever. Also respect the extensive editing this video must have taken.
I noticed you didnt throw the water pump intitionally, and you almost had me when you said you sold it. Your water pumnp skits are getting better and better
yeah yeah !!!!
Bro went and got the Diesel Truck breaker bar! ! Nice addition!
Excellent water pump skit right at the end. I thought a Procrustean process would be employed on the water pump to make it fit the smaller box... but I was mistaken. Excellent laugh, thank you! 😂😂😂😂😂
I’m no mechanic but love watching the teardowns also was wondering if maybe it would be a nice detail if u added a picture of how these cars look when talking about the engines
Each engine could be used in 10, 20 or even more models of car across numerous years. How many pictures would you want?
@@johncoops6897 He always states what vehicle the specific engine he's tearing down comes from, so all he would have to do is show that 1 vehicle. That's what the person above is asking.
@@l3LaZ3ful - He says it came out of a ML550 and this engine is also used in GL, S, E, CL, CLS and M series. Basically, every single Merc model range could have this engine in it. They were used in models from 2010 to 2020, so over 10 years that is a pretty huge range of vehicles. If people really wanted to know, I guess it would be very easy to just search Google Images if they wanted to know what a Mercedes vehicle looks like. I'd reckon that most people (especially those watching a car-related video) would know what a Mercedes ML series looks like, wouldn't they? . Yeah, I guess Eric could try to find a royalty-free high-res photo of an example of one of the vehicles to edit into the video. But in my opinion it seems like a bit of a waste of his time, especially considering that each engine is used in so many different cars anyway.
Just Google it bro
I agree... a pic n pic for a couple seconds would be just a extra layer of goodness for the channel... great suggestion IMO
9:03 The easiest way to get that off is to just shove the impact on and rattle the nuts out. It looks like the locking sheet steel is too thin to do anything useful and the impact won't even notice it.
Gotta love Saturday night!!
Watching Chino Moreno tear down a motor is always tue best part of my day
That's a pretty hefty crankshaft! Is the blue cast on the connecting rods heat treating, or are they made of somehting more interesting than steel?
It could be heat treating, or nitriding!
What’s crazy is if the goal is 400hp the design of this engine is ridiculous compared to other engines with 400hp, I’m thinking of some pushrod v8s.
The 4.7 is detuned compared to the 5.5 which shares virtually everything and makes about 585hp.
A tune and high flow cats nets about 750hp from these engines.
Makes more than that. Mercedes has a habit of underrating the power output of their V8s
@@waverleyjournalise5757sadly that 5.5 block is not very strong. 4.7 is a bit stronger but not much.
@@garyzhang5099 it's the same block
I am sooo glad I waited till the very end of this vid. Absolutely hysterical !😂
"return to sender, address unknown" was the song that came to mind in the closing video.
Re-leaf valve perhaps?
I was wondering where the water pump toss was! :D Thanks for my Saturday night entertainment Eric. Any idea what causes that bore score? Is it an oiling issue?
You got water pump roadkill instead, are you not entertained?
@@greebj - I actually laughed out loud when I saw it.
I'm really hoping that you get your hands on the 4.0 biturbo v8 now that teardown I would love to see im also hoping for a couple of volvo engines as well
What an absolute mess of a thing to work on. The motor itself actually looks like a very well built unit but what a packaging nightmare. GDI and broken head bolts just adds to the nightmare. This is the kind of thing that keeps me away from new cars. Even small engines look like overly complicated messes and the theme extends to the useless electronic gadgets lathered throughout. These vids are an excellent way to learn what to stay away from. Thank you for taking the time to do it.
The more complicated the engine, the more prone they are to Failure… Simplicity over complexity always wins!
In this case, the problem is that Mercedes ditched cast iron sleeves from their aluminium block, which basically makes bore scoring inevitable at 60,000 miles. It looks like a good engine otherwise.
Reading online, the M276/278/157 are supposed to be reliable, so far...