Moxostoma

A rattle when I start the engine of my 2013 C350 has been diagnosed by the local dealership as a stretched timing chain (at 78,000 miles!). They say the timing chain adjusters, four camshaft adjusters, and timing chain need replacement. They quoted $9,800 for the job. Is this as unreasonable as it sounds like it is?

Moto_Guzzi

That sounds rediculous if the right oil was put in the car at services, get 2nd opinion.

xsever

DON'T LET THEM TOUCH IT YET. This is a known problem with the M276 engine which is found in your car. Please read the attached bulletin which describes the problem and the fix. They are supposed to carry out the repair at their own cost.

gianton

On my 2013 C250 CDI a simple timing chain tensioner change fixed the rattle I was hearing on cold startups. You should get a second opinion from an indy first.

MB Marko

welp i knew if a timing chain on a chevy was 3000$, i knew a mercedes would be 3 times more!.

defiantly get a second or third opinion! I'd personally do what xsever is suggesting.

Moxostoma

Xsever, thanks for the bulletin. Unfortunately, my engine number is 276 9xx 30 423764 - higher than the engine numbers listed for repair. It seems like M-B still has a problem, though. Heck, a timing belt can last longer than that!

I'll be checking with the local indies Monday.

xsever

This is just sad. I specifically chose the 2012 C300 4MATIC so I get the reliable M272 engine because the early builds of the M276 were troublesome as this forum proves. What's saddening me is that when the M272 engine was launched, it too suffered from major problems (balance shaft wear). Why can't MB get its engines right the first time? I love my car, but the brand's reputation is not holding up with me at all.

Alfadude

That bulletin does say something to the effect that if that issue is present for an engine outside that range they are to fill out a form and open a case up to investigate. So, maybe if your car is affected you might still get some relief. At least worth looking into at the dealer.

Wish you luck.

Adi-Benz

Just trade it in for another one at that price jeez

Moxostoma

Thanks, Alfadude. I missed that part. I should have known I could open a PTSS case and sent it to SE! I'm going to the dealership today and give it a try.

Adi-Benz, after this experience, this will likely be my last Mercedes.

MB Marko

ehhhh every car has there issues, all you can do is keep the maintenance up to date and hope for the best lol. I feel my 2012 is rock solid i cant justify selling the thing....like 100,000KM and counting on my brakes and there still good! im at 180,000 original shocks, ball joints are good i've legit done nothing!!! but secondary air pump LOL and oil changes, transmission fluid change and brake fluid. i cant explain it but this car is a tank. every oil change i lift it and check everything it looks amazing.

xsever

The 2012s with the M272 engine are one of the most solid Benzes out there. Super reliable. I ended up with one thanks to hours and hours of research and not by luck.

One of the best lessons learned from research is to never buy a car the first year it's out and to never buy one with a first-year engine or transmission because that's when all the teething problems occur.

Moxostoma

Well I went to the dealership and asked about a PTSS case. The Service Consultant said that process was to verify the diagnosis, not evaluate the possibility of covering the repair by Mercedes-Benz. He did give me a phone number for M-B Customer Care to make a claim that the repair should be covered, at least in part, by Mercedes-Benz. Surprisingly, after leaving my information, a nice young man named Lance called back, but was perplexed as to what I wanted Mercedes-Benz to do. I told him M-B covered the same repair needed on mine on the same engine, and that apparently whatever correction they made in subsequent engines didn't work. He said he would review my record with Mercedes-Benz; how many cars I've purchased from them and maintenance records for these vehicles. Silly me, I thought the decision would be made based on how much Mercedes-Benz backs up their vehicles, not on how much money I've spent at their dealerships over the years.

I also asked the Service Consultant how many hours M-B allotted to the repair. He said 18 hours, but that it usually takes about 20 hours. OK, 20 hours, they charge $189/hour so 20 hours X $189/hour = $3,780. He said the total cost is $9,800, so if I subtract the labor from the total, that leaves $6,020 for parts and shop rags? He had no explanation.

I went to a local German repair shop ("Factory Trained German Technicians") and they quoted about $2500 for the repair. I told him the dealership said the top of the engine had to be pulled to get the job done; he said they could probably do it with a chain link.

xsever

Sorry about your experience but hopefully MB Customer Care takes care of everything. This is another horror story chapter in the M276 book.

Tom in Austin

Curious about the last poster's phrase "... horror story chapter in the M276 book" ... I did a search and couldn't readily find any other dramatic M276 issues discussed here in the W204 forum.

The OP's issue is certainly a bad one, but what am I missing that qualifies the M276 as having 'horror stories'?

xsever

Redo your search. The High Pressure Fuel Pumps (HPFP) are failing on these M276 engines at a rate faster than MB can produce them. It's all over the forum and the internet and the local dealership where I live and where my friend is a lead technician. The same applies to the OP's problem of timing chains rattles and the need to install non-return valves (check valves) and replace left and right secondary chain tensioners as per MB's service bulletins.

Moxostoma

Xsever, I was told the chain was "stretched" but from what I've read and what you say, it is really a problem with the chain tensioners. My understanding is that the tensioners are hydraulic and leak down over time. That's why the problem only occurs with a cold start. Since my engine number is not covered by M-B for this repair, does that mean that it came with check valves already installed in the engine?

xsever

I really don't know if the engines past that serial number came with the check valves from the factory, but if you stop and think about it, what a major item to not install originally and to have to retrofit. I don't know I just can't swallow these mistakes by MB with this engine.

Tom in Austin

Is a High Pressure Fuel Pumps (HPFP) an engine part? Sounds like something external that wouldn't reflect on the qualities of the engine ...

Moxostoma

For anyone following this saga who has a M276, there is no good news for you. Mercedes-Benz did give me a "Goodwill Offer." They offered me 10% off the repair cost, $1000 off a new M-B, or $500 off a used M-B. If I had a record of giving more money to M-B (they couldn't count all the parts I ordered from them online over the years), I guess I would have gotten a better deal.

I got the service advisor to print out a breakdown of the repair:

Parts:
Four (4) camshafts: 2@$1,086, 1@$1,064, and 1@$1,103
24 hydraulic elements: $967
1 chain: $122
1 chain tensioner: $177
1 chain tensioning rail: $283
Miscellaneous: $60

Labor: $4,625

Tax: $360

Total: $10,976.10

The advisor said there are a lot of 350's with this problem. He tried to tell me that M-B improved engines by going from timing belts to timing chains. I asked him if chains were so much better, why is the chain worn out on an engine with 76,000 miles on it. He just shrugged.

They did a recall, removing the air bag and steering wheel to put a clip on a ground wire. They're worried about a ground wire falling off but seem unconcerned that timing chains are chewing up camshaft sprockets.

Tom in Austin

Wow, that is sobering. I wonder why they propose to change all four cams and all 24 hydraulic lifters, but only one tensioner and chain? Would damage on one bank of cylinders affect the cams on the other one?

Was the original symptom a rattle every time you started the engine? Or did it only occur with a cold engine, or after the car sat for several days without being driven?

An independent might be able to source a set of good used cams (like https://www.ebay.com/sch/i.html?_fro...+M276&_sacat=0) and a set of aftermarket lifters, since that's where most of the parts money is. Obviously the labor is going to be a lot no matter where it's done :-(

Gazwould

Not unheard of but pretty rare .

How much was it ?

Strange how a very few suffer as others don't .

Moxostoma

Here's what the mechanic wrote up:

"Intake camshaft adjuster bad verified customer concern, performed QT fault code PO34600 position of intake camshaft has a malfunction, recommend replacement of camshaft solenoids to rectify customer concern."

It appears they want to replace everything so they won't have to go in there again. Understandable, but at a high cost.

xsever

@Tom in Austin That's more than enough horror for me especially for an engine with only 76k miles and outside the original range of affected engines by MB.

Anyway, I am sorry to hear this @Moxostoma . How much did you buy this car for and how much is it worth now if it were running in tip top shape?

MB Marko

Well an engine swap is probably way cheaper than this repair. Maybe you can cram a wrecked C63 engine in there for less money and have more fun.

I bet an engine swap is less hours and half the cost.