Is The Mercedes M278 A Worthy Mercedes V8? 

Having come from a 1st generation BMW N63, I’m loving my 2nd generation (2014) M278.

My dream car had always been my Love the W218 cls one day I will get one☝🏾💯🤲🏾

These motors chew through motor mounts because of all the power. Also the turbo coolant lines are all made of plastic and they get brittle and break and will leak. Also they have camshaft adjuster issues. Also have valve seat issues. And the turbos will end up going out at around 100,000 miles. They do tend to seep oil from pretty much every possible place. But as a Mercedes-Benz dealership technician for 22 years I really do love the power delivery of this motor but that's really about it.

Some of the stuff you mentioned is correct. I just purchased 2015 GL550 60k miles Fucking think was pissing oil all over the place. Front engine valve covers resealed front cam magnets replaced all four cam shaft sensors replaced. Added adapter harnesses on cam shaft sensors to prevent oil going inside engine harness. You said if you end up with oil inside engine harness just replace cam shaft sensors and you good. Well not tru if oil reaches your ecu you are fucked. You have to drop engine replace ecu/ computer whole engine harness. You forgot to mention driver side engine mount will blow out every 30-40k miles On my car engine mount was replaced at 28k miles and I just did it at 60k miles. Now I have 2014 BMW 550i with 70k miles I purchase this car in California with 10k miles. Most people will tell you N63 engines are junk not tru some of the engines before 2013 did have more issues than engines after 2013. I can tell you with confidence it’s one of the best cars I ever owned. Trust me I owned a lots of cars. I did few repairs on it big one was valve seals replacement. After repair was done car still drives just like it did when I purchased 8 years ago. Now conclusion on M278 engine I have family trip coming up after I come back I will be selling my GL 550. Due to crap is failing a part Front suspension is squeaking top of the steering wheel I can tell inside it’s loos No space to work on anything I forgot to mention radiator was replaced when I purchase the car. So yes M278 is crap

Have 2014 ML550,so far,65k miles so good.Thinking some proactive "service" re do the coolant lines fittings, and the cam covers to get me another year or two. Love the sound and power.

If you replace the brittle coolant lines, is there an aftermarket better version? Or, can the coolant lines be wrapped to prevent the heat from making the brittle?

I too had to 07 S550 now a 2012 S550 with M278

Patiently waiting for the E55 update lol

I own 2016 S500 with M278 engine. So far the car is at 118k km or 73k miles and the only things I have changed are spark plugs and the usual oil, filters etc. Just now I noticed leaks from both camshaft solenoids. I change the oil every 5000 miles. I heard that those engines have issues with cylinder scoring due to weak aluminum/silicon low-friction cylinder liners called Silitec. I don't know if it's a major issue or not.

Anyone with a CLS 550, 2013 and up, metal shavings in the oil filter and oil pan?

M278 cam sensor oil wicking problem

the o rings on the camshaft sensor has nothing to do with it leaking inside the wire that's to prevented it from leaking outside , the leak you are talking about is internal has nothing to do with the o rings .

M273 was rated at 382hp, I had an 07 S550 as well, lost compression on cylinder 2 and had the infamous idler gear pulley issue. I am now looking to go 2013 S550 or 2013 Cls550.

i absolutely love these motors. you can tune these up to 600hp depending on the chip, but you’ll likely blow out the transmission at that point. my fear with these cars is the air suspension which inevitably gives out before 100k miles. also, engine mounts are common failure in these. overall a reliable engine though

They ditched 5.5 na bcus of lower emissions on biturbo engine not bcus it wasnt powerfull enough😁

Just had intake passenger cam and adjuster changed.. $6500

5.5 na is about 280g emissions and 4.7t is about 215g

This engine actually has AMG parts, i was replacing oil filter housing and it had AMG stamps. Then i did research and it is real baby AMG engine. To install downpipes - engine out, lots of vacuum hoses or small coolant hoses are brittle due to “hot engine” design. At the time i owned it the lead time for those hoses was 5 months from Germany. Be careful when u service the engine it is very brittle.

My 2014 w212 E550 has been gaining problems day by day it’s at this point it’s a money pit had 2 coolant leaks in the past 2 months and the water pump went out at 87k Kms

CLS55 better looking than this? They must be smoking dope. The CLS generation before this was ugly, the headlights were terrible and so were the taillights