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My 2018 C300 C Class Coupe M274 E20 GA 205.348.22-AU3 had a catastrophic engine failure at just over 13,000 Kms.
Diagnosis thus far is that Cylinder 1 Piston is cracked.
Codes I was able to catch after the engine would no longer start and the check engine light was displayed. Just so happened that day I had a OBD2 reader lying around after doing work on a friends car. Downloaded Carly and the full license for my car.
P030085 Combustion misfiring has been detected.
P030185 Combustion misfiring of cylinder 1 has been detected.
P030285 Combustion misfiring of cylinder 2 has been detected.
P030385 Combustion misfiring of cylinder 3 has been detected.
I had been on the road for less that 4 mins, when the car lost all power while accelerating from a stationary position. Prior to this no warning indicators had been displayed in the dashboard instrument cluster, no warnings were even displayed when the engine failed.
The vehicle is well serviced, very well maintained, in exceptional overall condition.
The never drive the car hard unless it is at operating temperature of approx. 95. deg C.
I will be pursuing a claim with Mercedes Benz seeking an entire engine replacement.
Whist my car is just outside of MB 2 year manufacture warranty in our country we have Consumer Guarantees that stipulate all businesses must provide a set of "automatic guarantees" regardless of standard manufacture warranties.
Last edited by davidijames; 08-11-2022 at 10:44 PM.
Reason: Removing some personal identifiable information so I can keep the group better informed on the progress of my claim.
Sorry to hear. Best of luck with the compensation claim. The M274 has a poor record of piston cracking, sad to say. This is the lowest mileage cracked piston report I have seen, and on the last production year in the C-Class, before changing the M264, an engine related to the M274 through common fundamental parts.
Approx. 3 weeks passed from when I lodged my claim with MB for our Country. I called MB hotline (which for our country appears to be MB roadside assist operated out of Malaysia). I began to feel Malaysia was not geographically motivated, so I politely requested a number and email for MB Group Germany.
I made a call and forwarded on my original letter and with in 12 hours, my local dealership called to advise they have received authorisation to repair my engine (they had also advise they were preparing a technical workshop case to seek assistance), I.E strip it down, find out how many pistons are cracked, including other damaged components, valves and or block. Given how the misfire occurred I wonder if the ECU turned off number 1 injector and wound back timing to attempt to save the engine or did the timing chain fail ?
Naturally their response is a good start, but only a start.
I short I don't want the same potentially defect piston / wrist pins replaced. I feel it's fair to assume the others have likely began cracking. I don't like to tell people how to do their job, but surely it would make sense to crack test them (including, block, head) to inspect for potential premature ware / damage, including just swap them all out “hopefully" where a new piston exists.
I don't want the same issue in another 10 km - 100,000 km, nor would I imagine they would too.
If I could source after market forged pistons I would pay for these to give me peace of mind.
In the event the block is damaged I would assume it is easier, more efficient to swap out the engine with a new one.
Would it be a new engine or factory refurbished and would it have the same defective pistons in it, all things in need to consider.
Approx. 3 weeks passed from when I lodged my claim with MB for our Country. I called MB hotline (which for our country appears to be MB roadside assist operated out of Malaysia). I began to feel Malaysia was not geographically motivated, so I politely requested a number and email for MB Group Germany.
I made a call and forwarded on my original letter and with in 12 hours, my local dealership called to advise they have received authorisation to repair my engine (they had also advise they were preparing a technical workshop case to seek assistance), I.E strip it down, find out how many pistons are cracked, including other damaged components, valves and or block. Given how the misfire occurred I wonder if the ECU turned off number 1 injector and wound back timing to attempt to save the engine or did the timing chain fail ?
Naturally their response is a good start, but only a start.
I short I don't want the same potentially defect piston / wrist pins replaced. I feel it's fair to assume the others have likely began cracking. I don't like to tell people how to do their job, but surely it would make sense to crack test them (including, block, head) to inspect for potential premature ware / damage, including just swap them all out “hopefully" where a new piston exists.
I don't want the same issue in another 10 km - 100,000 km, nor would I imagine they would too.
If I could source after market forged pistons I would pay for these to give me peace of mind.
In the event the block is damaged I would assume it is easier, more efficient to swap out the engine with a new one.
Would it be a new engine or factory refurbished and would it have the same defective pistons in it, all things in need to consider.
Thanks for posting. Hopefully MB does the right thing and replaces the entire engine. Please keep us updated.
What they should do, what the right thing to do (both by the car and the customer) remains to be seen. If it was my brand, I would be doing a straight engine swap even offering a M624 (if at all possible). I will update this thread as this plays out.
Took a while but MB finally agreed to repair the engine at their expense approx. 12 hrs after I called head office in Germany and after ghosting my local dealership in Australia for weeks on end. Fortunately I did not need a car. Note, I never received a reply from Germany.
Shortly after agreeing to repair my car they advised they needed to replace the engine (also at their expense). A courtesy car was included the same day as they began their works. Not a sorry or anything of the kind when I picked it up, it did not even get the standard car wash.
What now annoys me is that what I thought was a "New Engine" is in fact just a "Long Block (in which the entire crank assembly including the cylinder head, valves, injection and much more have been completely overhauled and installed using only MB Genuine Parts), compared to a New Engine or New Basic Engine or Basic Engine or Long Block Plus. In short Long Block replacements are a “remanufactured engine” that does not get tested on the manufactures test stand before been sent to the dealership. You can learn more about that at b2bconnect.mercedes-benz.com/gb/products/remanufactured-parts/cars/engines/basic-engine
Even more annoying is that the this Long Block from the "new engine number” 454,306 provided appears to have been produced 86,479 before my failed engine “540,758" OR approx. 47,704 after MB modified their faulty wrist pins that were installed as of engines in 2015 engine number 274 920 30 406 602 on which leads me to believe this engine may have been produced in 2016-2017 ??
Someone please correct me if my understanding about the engine number is incorrect.
Anyway its now been 5 months and with 2,002 km on the engine and is already more noisey on cold starts that the original engine. Transmission also notably louder. I don’t know what to do, I just know I don’t trust this engine, or MB and I will never buy another MB again. Is it all in my head or should I flick it.
If you are interested in what a new m274 long block sounds like with 2,002 km you can download my videos at recorded on a iPhone 101a M274 2018 Cold Start 3m 30sec - 37-40 deg celsius.mov https://www.icloud.com/iclouddrive/0...40_deg_celsius
1c M274 2018 Cold Start 10 secs at 50 70 80 95 96 deg celsius 4-10.zip https://www.icloud.com/iclouddrive/0...g_celsius_4-10
No warranty was offered on the new long block as it was done under warranty.MB also returned it with a broken PVC line (crank case vent line) and a torn aftermarket pod air filter. Fortunately as soon as I drove it the 2k drive home I inspected their workmanship. Had I not caught this vent line it would not have been too long before I was back for another engine replacement. New Engine Number : Teil-Nr is the Long Block part number
Last edited by davidijames; 04-07-2023 at 07:24 PM.
Reason: Updated Video Recordings and ULRs
Took a while but MB finally agreed to repair the engine at their expense approx. 12 hrs after I called head office in Germany and after ghosting my local dealership in Australia for weeks on end. Fortunately I did not need a car. Note, I never received a reply from Germany.
Shortly after agreeing to repair my car they advised they needed to replace the engine (also at their expense). A courtesy car was included the same day as they began their works. Not a sorry or anything of the kind when I picked it up, it did not even get the standard car wash.
What now annoys me is that what I thought was a "New Engine" is in fact just a "Long Block (in which the entire crank assembly including the cylinder head, valves, injection and much more have been completely overhauled and installed using only MB Genuine Parts), compared to a New Engine or New Basic Engine or Basic Engine or Long Block Plus. In short Long Block replacements are a “remanufactured engine” that does not get tested on the manufactures test stand before been sent to the dealership. You can learn more about that at b2bconnect.mercedes-benz.com/gb/products/remanufactured-parts/cars/engines/basic-engine
Even more annoying is that the this Long Block from the "new engine number” 454,306 provided appears to have been produced 86,479 before my failed engine “540,758" OR approx. 47,704 after MB modified their faulty wrist pins that were installed as of engines in 2015 engine number 274 920 30 406 602 on which leads me to believe this engine may have been produced in 2016-2017 ??
Someone please correct me if my understanding about the engine number is incorrect.
Anyway its now been 5 months and with 2,002 km on the engine and is already more noisey on cold starts that the original engine. Transmission also notably louder. I don’t know what to do, I just know I don’t trust this engine, or MB and I will never buy another MB again. Is it all in my head or should I flick it.
If you are interested in what a new m274 long block sounds like with 2,002 km you can download my videos at recorded on a iPhone 101a M274 2018 Cold Start 3m 30sec - 37-40 deg celsius.mov https://www.icloud.com/iclouddrive/0...40_deg_celsius
1c M274 2018 Cold Start 10 secs at 50 70 80 95 96 deg celsius 4-10.zip https://www.icloud.com/iclouddrive/0...g_celsius_4-10
No warranty was offered on the new long block as it was done under warranty.MB also returned it with a broken PVC line (crank case vent line) and a torn aftermarket pod air filter. Fortunately as soon as I drove it the 2k drive home I inspected their workmanship. Had I not caught this vent line it would not have been too long before I was back for another engine replacement. New Engine Number : Teil-Nr is the Long Block part number
07-30-2022, 06:14 AM
MB agrees to replace the engine at their expense.
