Could anyone tell me the reliability on the E550's?
Any help would be great on clarifications and recommendations.
My 2014 has had nothing but normal maintenance and it is a rocket ship, plus it gets tremendous mileage. It’s quite a machine.
You can also tune these cars to 550+HP if you are so inclined for $2-2.5K. There are no real options for adding significant horsepower to the 350 V6.
I think the 2014-15 facelift models are one of the greatest looking and performing non-AMG sedans Mercedes has ever produced.
If you can find one, buy it. They are rare
My 2014 has had nothing but normal maintenance and it is a rocket ship, plus it gets tremendous mileage. It’s quite a machine.
You can also tune these cars to 550+HP if you are so inclined for $2-2.5K. There are no real options for adding significant horsepower to the 350 V6.
I think the 2014-15 facelift models are one of the greatest looking and performing non-AMG sedans Mercedes has ever produced.
If you can find one, buy it. They are rare
Biggest failure points are the plastic cooling systems, which are an issue on every version of every MB engine at this point, but in general they are very stout. Real failures are few and far between, a well serviced example with a ton of miles on it will usually be more reliable than one that has sat and not been driven.





Biggest failure points are the plastic cooling systems, which are an issue on every version of every MB engine at this point, but in general they are very stout. Real failures are few and far between, a well serviced example with a ton of miles on it will usually be more reliable than one that has sat and not been driven.
but same concern you will have eventually.Hi Joe,
I been wondering about plastic parts too, and this will decide if it is worth it to keep my E400 beyond 10 years.
Since you have lots of experience, what is safe years and mileage to change all plastic parts handling oil and coolant or whatever vital hot fluid it may be ?
Mine is 3 liter V6 Dela 30 with extra heat from the turbos.

I really fear the plastic water pipe ( A2762002052 Water Feed Line ) behind the engine, near the bulkhead, as I can't even inspect it, let alone replace it.
If I keep the car to say 15 years, I was thinking to change all plastic handling coolant and oil at 10 years of car age or early 2024 , including the radiator because the sides are plastic.
Any such parts if failed while I am at cruise speed or while doing agressive driving, my engine will be wrecked for sure.
Thanks very much Joe.
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Mine has been good to me and I drive it hard. nothing other than regular maintenance over last 2 years...well, unless you count performance mods!
ECATX TCU Tune
Stock Turbos
3" MBH Downpipes
11.3 @ 122mph (Dragy)
3.5 seconds 0-60mph (Dragy)
trans seems to be okay so far, but I do have 115k miles so no promises on that. I assume I'll need one before too long, but I'll have one built I'm sure. Having motor mount issues right now so I think next mod will be ECE Motor Mounts, then I can get back to my quest for 10's without having to worry about damaging anything. That BlackBoost intake is looking pretty good as the next candidate after that along with some resealing of cam adjuster plates and new water lines for the turbos.
Biggest failure points are the plastic cooling systems, which are an issue on every version of every MB engine at this point, but in general they are very stout. Real failures are few and far between, a well serviced example with a ton of miles on it will usually be more reliable than one that has sat and not been driven.
but same concern you will have eventually.Hi Joe,
I been wondering about plastic parts too, and this will decide if it is worth it to keep my E400 beyond 10 years.
Since you have lots of experience, what is safe years and mileage to change all plastic parts handling oil and coolant or whatever vital hot fluid it may be ?
Mine is 3 liter V6 Dela 30 with extra heat from the turbos.

I really fear the plastic water pipe ( A2762002052 Water Feed Line ) behind the engine, near the bulkhead, as I can't even inspect it, let alone replace it.
If I keep the car to say 15 years, I was thinking to change all plastic handling coolant and oil at 10 years of car age or early 2024 , including the radiator because the sides are plastic.
Any such parts if failed while I am at cruise speed or while doing agressive driving, my engine will be wrecked for sure.
Thanks very much Joe.
Thanks for the heads up
If you want rear wheel drive, you will need to buy the coupe or cabriolet.

http://www.auto-brochures.com/mercedes_benz.html
I also like to use Motor Trend. You can see what the price of some of the options were for a particular model and then click on features further down. Just change the year in the url for the different model years.
https://www.motortrend.com/cars/merc.../e-class/2012/
Then use a vin decoder to get the options you want. I always want the lighting package, pano roof and at least parktronic and a few other options like driver assistance, but it's hard to find them loaded and most ads lie and say they're loaded and the option isn't on there.
https://www.lastvin.com/
What timing chain issues are you referring to Johnny, all the engines had tensioner issues and the chains can stretch when maintenance is neglected, that applies to all the v6 and v8 engines, and even the 4 cyl engines although the root cause was different and they didn't have the tensioner update bulletin.




What timing chain issues are you referring to Johnny, all the engines had tensioner issues and the chains can stretch when maintenance is neglected, that applies to all the v6 and v8 engines, and even the 4 cyl engines although the root cause was different and they didn't have the tensioner update bulletin.
well noted on the visual pre-caution and slow leak. I sure hope it is the slow leak and not immediate broke-into-2-pieces scenario.Good thing I do not have winter , I am in the tropics. However, my traffic jam is very bad. 20km/h is the average speed I been getting prior to covid for the last 400 hours or 10,000KM or 2 years.
So hours of exposure to heat for my mileage is kinda high when compared to US cars. With less vehicle speed, I guess ambient temperature in engine bay is hotter too.
Slight tune on them, and they blow up.
Don't buy it.
Seriously ppl quit recommending the M278's, if they can't be bothered to research the hundreds of post showing how good these engines are, they don't deserve them.
(And above I was having a nightmare about my old S85 M5 and my N63 550i)
Slight tune on them, and they blow up.
Don't buy it.
Seriously ppl quit recommending the M278's, if they can't be bothered to research the hundreds of post showing how good these engines are, they don't deserve them.
(And above I was having a nightmare about my old S85 M5 and my N63 550i)




Any help would be great on clarifications and recommendations.
It seems there are more issue with these cars starting from 2012 year model with the bi-turbo engine. Issues seem to be with brakes but I cannot say how much the engine has to do with it. The 5.5 Liter engine prior to 2012 seems rock solid and the one i have still runs without burning a drop of oil between oil changes that I do every 5000 miles.
I just got a 2013 S550 that I now drive. Don't need the E550 that much anymore but cannot let it go for a book value of well less than $10 000. It has 180 000 miles on it but they are 85% highway so comparing to a city car it has only about 65 000 miles on it. Awesome car with all gizmos working (has driver assistance package). And it is the best looking E-Class with the hockey stick DRL's on top of the best ever Bi-Xenon main lights in the front.
It seems there are more issue with these cars starting from 2012 year model with the bi-turbo engine. Issues seem to be with brakes but I cannot say how much the engine has to do with it. The 5.5 Liter engine prior to 2012 seems rock solid and the one i have still runs without burning a drop of oil between oil changes that I do every 5000 miles.
I just got a 2013 S550 that I now drive. Don't need the E550 that much anymore but cannot let it go for a book value of well less than $10 000. It has 180 000 miles on it but they are 85% highway so comparing to a city car it has only about 65 000 miles on it. Awesome car with all gizmos working (has driver assistance package). And it is the best looking E-Class with the hockey stick DRL's on top of the best ever Bi-Xenon main lights in the front.







