Hmmm when mine when out, I would have been pissed if they just just repaired it. I didn’t have to argue back and forth, they just went ahead and replaced the entire engine block, but they said there was damage to the cylinders. It runs great, except for that rare random transmission knock at low speeds but I can’t replicate it to get it fixed!

 

Good luck with this. I brought my car into the dealer for 4 years complaining about the noise. The entire time it was under warranty but they did nothing. I was told it was supposed to be loud. They blamed the piston slap noise on fuel Injection and said it was supposed to be loud. The piston cracked after it was out of warranty so they refuse to do anything to help me. MB Corporate was horrible. They blame me for not having the dealer fix it while it was under warranty. I had to pay for everything myself.

 

The diagnostic for this situation under either New Car Warranty (4yr/50K miles) or Mercedes Certified Warranty - the work is done under the direction of MBUSA to the dealer - including approval for tear down - and then digital photos on the cylinder/engine internals.

Yes- cracked piston repair can be replacement of that piston (no cylinder wall and/or black damage) or full engine replacement if required.

In "general" this type of failure seems to happen most in urban areas - where their is a very wide range of available fuel - and lower octane fuel - and/or contaminated fuel - "can be" one of the major contributing outside factors.

 

The dealer never diagnosed it. The car was brought in several times while under warranty and even though I constantly complained about the noise, they failed to recognize the problem. My car is an early built 2015 and clearly had the wrist
pin issue.

 

I understand on how upsetting this situation was for you - but please understand that a cracked piston doesn't go on-and-on-and-on as a "ongoing fuel injection type noise" - a cracked piston is a abnormal mechanical failure - think of a cracked piston as a "dramatic event""

 

So how much money do you have on hand? You're going to go to a lawyer and propose what? I'd like to sue Mercedes-Benz for honoring the warranty and repairing my car? Good luck on that. Mercedes repairing your car under warranty is not "taking advantage of you". You guys seriously need to get a grip.

If the car is repaired and performs 100% as it did prior to the repair, then this Mercedes' legal obligation fulfilled. You have no rights to anything else. These cars are not made of magic and fairy dust. These engines are repairable. I don't blame them for not swapping the entire engine unnecessarily nor do I understand why you'd even want that.

 

My car was definitely affected by inferior wrist pins. It is surprising that it was never diagnosed during the time it was under warranty. It was manufactured during the period when it was a known problem and the engine number is within the range of affected engines. It should have been fixed during one of the many trips to the dealer, Instead it was ignored. They never even checked it. They just kept saying it was supposed to be loud.

 

Hi Guys,

I have a 2015 C300 with exact same issue as posted in this thread. I have a cracked piston on cylinder 1 and I am out of warranty. So finally my car is a piece of junk right now.
I am thinking of getting it fixed as I have no other option at this point.

How much should this kind of job should cost? I am located in bay area CA, anybody knows a good mechanic who can fix this ?

 

Cost will vary anywhere from $8 - $10k+ depending on whether the current engine/heads are repairable and if they do just the one cylinder or all of them.

My go to for non-dealer work is https://www.eastbayautohaus.com/
but they are in the far East Bay out by me. Great guys to deal with!

 

lol, the plague continues.

 

Thanks to all that shared in this thread. After my last service at 57K told me I needed some 5K in (front diff seal, axle seal, cracked muffler) repairs, I was thinking of selling my 2014 w204 and either leasing a 2020 w205 or buying a 2018 w205 or E300. After rereading these horror stories - I decided to have the repairs done at an Indy for less $, and keep the car for a couple more years as it's been pretty reliable. I am also thinking that I will prioritize finding a 6 cyl replacement when the time comes, if there are continued issues with the 4s. Good luck to all with best outcomes.

 

Pitching into this thread: My 2017 C300 Coupe has a cracked piston in Cylinder 1 as well. My car has exactly 45,000 miles on the dot, so luckily I'm still under the manufacturer's original warranty. I was idling at a red light when the engine shuddered and just quit with a big plume of white smoke from the rear. Once I opened the hood after manually pushing the car to the shouler, I saw splattered coolant and engine oil all over the engine bay. Basically a blown head gasket/head. Towed the car to the dealer where they tore the engine down and confirmed that the piston in Cylinder 1 is cracked. Waiting on news to see if the cylinder walls are also damaged, which will dictate whether the car needs a brand new engine or just a new set of pistons.

I was originally planning on buying this car out (it's a lease) in 2 months, but thankfully this catastrophic blowout happened just in time for me to have it covered under warranty and get the hell out of the lease. Dealer confirmed that they have several other cars with the M274 engine with the same exact issue. Seems like a somewhat widespread manufacturing or design flaw with these engines.

 

—-////———————————————-////————
i have been complaining to the dealership for the past year something was not right. I have an extended warranty thankfully but this was the message from them :

Hi tech confirmed a noise from the pistons, which could also be responsible for some vibration. Pistons are being replaced under your warranty, which will also cover your engine and tranmission mount replacement. Only squeak/squeal heard otherwise was brake noise. Will update on progress tomorrow-
——-/—-
this car has something wrong with it constantly I have been in and out on a regular basis - . Everything so far has been on warranty or extended thank goodness but this complaint on losing power hesitation, my sun roof , windshield wipers, seat rattled and a long host of issues but all covered and repaired. Car has 60k+/- miles on it, now. Seems the pistons are an issue . That’sa big ticket item. Make sure you have the extended warranty on any Benz. I love my car but the repairs are insane. I got it in 2018 with 25k miles on it. I’ll be getting another different make car next year most likely. My warranty expires then.

 

Here is what I know now and here is what MB have learned. The W205 was build in American where the ML have been built for years. MB makes more money and sells on C-Class then any other car they sell. To save money on shipping, the decision to build the C-Class in America was a big mistake. After all the issues from owners that notice the issues because they either owned a Benz previously or new to Benz and noticed fitment issues, engine issues, brake issues and list goes on. MB decided, even thought Trump does not like it, to import their cars again, mostly the AMG brand names. Hence if you looks, you will find the the new C43 and all the AMG brands are not built in Germany and shipped to Canada and the USA.

 

This has nothing to do with it. They were producing the C-class in Vance, AL but the engines were sourced from Germany. The engine piston failures being discussed in this thread are not related in any way to the final assembly point in Alabama.

 

My old 2011 W204 was the most worry free Benz I ever owned, until Takata ruined that. (lovely 6 cylinders and sweet engine sound)

I've been waiting almost 8 years for the replacement airbag and only now MB is contacting me to come in.

I traded in the car in 2018 for my W205 CPO.

 

Wish I would have seen this thread before purchasing my car.

Confirmed 2018 c300. Cracked piston 1 at 43,xxx mls
Covered under warranty. Replacing piston. Will update when I talk to the dealer.

 

"Confirmed 2018 c300. Cracked piston 1 at 43,xxx mls"

Hmm. I wonder if there many reported incidents of cracked piston 1 for the 2017 and onward MYs?

 

I'm assuming the CPO limited warranty that starts when the manufacturer warranty ends covers this as well?

 

In these cases of cracked pistons, would changing your spark plugs to the new interval of "Every 46,500 miles or 3 years" help as preventative maintenance? (Maybe even changing them out earlier?)
From what I've read these spark plugs fire way faster than traditional spark plugs so I imagine going over their service life causes wear in the combustion chamber? Just thinking of ideas/solutions as I plan to keep the car and haven't had many problems with mine.

 

Unfortunately that would be a big no. That is what I was told when my car was dropped off again 2 days ago for the same piston issue and I am at 49,900 miles

 

Getting towed to the mechanic again

 

Wait, what? Aren't pistons, piston rings, etc considered "internally lubricated parts" which "all" are noted as being covered in the CPO Limited Warranty?

 

CPO should cover this.

 

A recommendation that if you are able to still purchase the ELW, consider doing so, given the problems you have documented with your car.