Mercedes ML550 M278 Bi-Turbo V8 Engine Teardown. Unavoidable Failure?!

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!

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 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.

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.

Literally every time Eric said “Bore score” My brain immediately autocompleted it to “Bore score and seven years ago”

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 water pump and timing parts gags are gold.

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.

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.

I have a toddler that loves these videos. It has become a Sunday evening tradition. Thanks for keeping them going.

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.

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.

I believe the mini oil pump is for scavenging oil from the turbos.

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

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.

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!!

Thank you for all your great videos. I watch more YouTube then I do regular TV. I've learned a lot about different engines. Love it!!

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. 😂

Perfect way to cap off my night with one of these uploads. Thanks man.

You should show us how do you get a broken bolt like that one. Your videos are great.