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They are very much aware of it, our '21 GLC300 with 46,000 miles and 6 months out of warranty threw the CEL with all the right codes about 2 weeks ago. Took it to the dealer and started the negotiation for a goodwill warranty repair, and W140king's posting of the above letter was all I needed to get the repair covered under warranty. Picked up the car on Friday, all good (for now). Here are three pages of the invoice to show their workup (80% leakdown (!) on the bad cylinder #1) and all the parts replaced. Perfectly timed failure.
Thanks for your posts guys i will go there tomorrow and get to the bottom of it 👍
I got the same canadian version of the letter in late December. Called the dealer but they didn't explain much other than the engine might comes on and MB will extend the warranty. The car can still drive safety. Can someone explain in simple English what was the letter about? What are the symptoms if it happen? I think I have experienced a few times that when I tried to accelerate, it felt like some misfire (a jerk of some sort). I softly tap on the accelerator like when you are in bumper to bumper traffic. This is no code and no engine light though..
Last edited by dadalook; Jan 19, 2026 at 04:16 AM.
I got the same canadian version of the letter in late December. Called the dealer but they didn't explain much other than the engine might comes on and MB will extend the warranty. The car can still drive safety. Can someone explain in simple English what was the letter about? What are the symptoms if it happen? I think I have experienced a few times that when I tried to accelerate, it felt like some misfire (a jerk of some sort). I softly tap on the accelerator like when you are in bumper to bumper traffic. This is no code and no engine light though..
Thats how it starts minor once in a while no cel . It than progressively gets worse cel will come on . You will also notice misfire on idle again here and there minor but eventually gets worse
The 80% leakdown on cylinder 1 on my motor blew my mind, at that level of leak it surprised me that it ran as well as it did. (Only drove it ~5 miles from home to the dealership after the CEL came on). Though these 2 liter turbo direct injection motors all sound like VW diesels to me, so perhaps it was misifiring to a lesser degree pre-CEL and I just didn't hear/notice it.
Thats how it starts minor once in a while no cel . It than progressively gets worse cel will come on . You will also notice misfire on idle again here and there minor but eventually gets worse
Is it a matter of when it happen? All MB vehicles with M264 are affected? I dont know if the symptoms I described above were actually it or just a case of trying to accelerate but not pressing on the gas pedal hard enough and releasing it.
If it is the case, how long do they keep the vehicle for? I assume they will have loaner during the repair?
Is it a matter of when it happen? All MB vehicles with M264 are affected? I dont know if the symptoms I described above were actually it or just a case of trying to accelerate but not pressing on the gas pedal hard enough and releasing it.
If it is the case, how long do they keep the vehicle for? I assume they will have loaner during the repair?
pretty much . Im not sure how long it takes to fix but a loaner for sure . The cel may come on and go out but once its on the codes are stored and your ready for repair . Went to dealer in person today and they verified that warranty has been extended . If it wasnt fir this thread i would not of known . Even chat gpt thinks its canada only
Good news - got my letter in the mail today from Mercedes USA for the M264 Exhaust Valve System warranty extension; and it does include on the whole backside language for reimbursement to those who already had to have it done on their own dime in part or full -
If it is the case, how long do they keep the vehicle for? I assume they will have loaner during the repair?
As a data point, I dropped the car off on 1/8, they finished it on 1/15, so a week. I didn't get a loaner as we have other cars and didn't want to deal with the hassle. They did offer one, however.
Hello, I pick up my e350 tomorrow which will have 3.5 years warranty on it and I want to get a basic scanner to check for codes but don’t want to spend big bucks. Anyone got any suggestions?
thanks for your help 👍
I have an OTOFIX D1 lite as well as a Xentry system from BenzNinja- For $330 the D1 lite does almost everything the Xentry can, and is much simpler to connect to the car and just use. I used the OTOFIX to diagnose my CEL when my M264 motor's exhaust valve guides started going bad.
I have an OTOFIX D1 lite as well as a Xentry system from BenzNinja- For $330 the D1 lite does almost everything the Xentry can, and is much simpler to connect to the car and just use. I used the OTOFIX to diagnose my CEL when my M264 motor's exhaust valve guides started going bad.
As a data point, I dropped the car off on 1/8, they finished it on 1/15, so a week. I didn't get a loaner as we have other cars and didn't want to deal with the hassle. They did offer one, however.
That was fast. They must have stock then otherwise it should take a while to get stock from Germany.
What symptom did you have prior dropped off? What odometer do you have? I wonder when mine will happen? Currently 58K.
So I emailed and called Mercedes Benz Australia today and sent them the Mercedes Corres from Canada and USA of the 10 year extended warranties for 2018-2023 M264 (which I found on this amazing forum) and they told me no extended warranty is being given to Australian customers- yet.
I certainly hope they look after the rest of the world and give us all the same extended warranty on m264 engines. We can only hope.
What symptom did you have prior dropped off? What odometer do you have? I wonder when mine will happen? Currently 58K.
Check engine light, no rough running. Contacted dealer for an appointment, didn't drive the car until I drove it to the dealership, during which it was misfiring and running poorly. ODO was 46647. 6 months out of the original 4 year warranty. (Awesome engineering by the powertrain warranty team! )
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