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Last month on my way to work I came off the freeway, pulled up to stop light and noticed a rough idle, the engine check light flickered. I made the left and pulled up to the next stop light, engine check light came on with a very rough idle. I made it to work and called my MB indie mechanic. He said don't drive it, have it towed to my shop, in it might be the pistons, I'm like WTF! He said he had replaced the #1 piston on a 2016 GLC 300 two weeks prior.
I had my car towed to his shop. After diagnosing, it turned out the #1 and #3 pistons are both cracked, the cost to repair $9K. My car only has 32,000 miles on it!!!
Not only were my pistons cracked but the rod bearings had abnormal wear and needed to be replaced as well. Check out the burn pattern, heavy on one side and clean on the other. My rainy day fund just evaporated.
Really disappointed with MB, I have been driving only Mercedes for the last 30 years with ZERO issues on any of my cars. I will be signing up everywhere I can to get MB to pay for the repair.
Meanwhile I'm having to drive my convertible '03 CLK430 as a daily driver. That car just turned 60k mi and runs like a bat out of hell. "They don't make 'em like they used to..."
Now that I have pics I'll need to start the process against MB and NHTSA. I'll post what ever I find to help anyone who may have the same problems, please do the same....
2016 S550 sport, 2018 GLC300, M3, Zo7, 2021 Sierra Denali
As soon as my MB extended warranty is up, our GLC will be traded in! a 10K repair on a 15k truck is just not feasible. I bet a 2018 GLC next year with 90K on it wont even be worth 15K,,,,,,,,not awaiting this problem. But many will say its not a big issue or even an issue at all. Well IF it happens the repair cost is outrageous on a cheap truck. I have owned many Mercedes and own an S550, they all have some issue. But issues one can fix, or it pays to fix. But the 3.5 balance shaft issue and the cracked piston issue are very expensive repairs that can exceed the value of the vehicle. We love our GLC, but not gambling after the warranty. Sorry your going through this.
Years ago we owned a Chevy Traverse which had a known issue of the timing chain stretching. Even GM stood up and gave an extended warranty for 10 yrs/120K!! Shame on Mercedes.
It's so sad you are dealing with this, my personal observations are:
piston does look bad, especially on one side, looks like it was very hot in the cam and not equally speeded in cylinder as it's more on one side, with amount of soot it was accumulating it for some time. bad injector ? bad gas? low octane ? I would think. Very strange looking after 31K miles only.
Rod bearings, abnormal wear like this usually cause by wrong oil (spec) or long intervals. According to a Lab results for the oil I've sent to them after 4K and 3K miles,
it's already too thin at high temps. Used oil from 3 different brands, all 5w40 229.5
good luck with MB, I would report to BBB and consumer reports as they shows no major engine issues for 2018 year.
why did you not go to dealer to start as maybe they would have repaired under warranty for powertrain?
Or squeeze it in the 80K emissions warranty since you would not pass a proper emission test with that issue.
Does suck big time and in all my years never had a normal car driven on roads crack pistons.
just takes one owner to speak up about an issue like this and MB gets blackeye which it should.
Last month on my way to work I came off the freeway, pulled up to stop light and noticed a rough idle, the engine check light flickered. I made the left and pulled up to the next stop light, engine check light came on with a very rough idle. I made it to work and called my MB indie mechanic. He said don't drive it, have it towed to my shop, in it might be the pistons, I'm like WTF! He said he had replaced the #1 piston on a 2016 GLC 300 two weeks prior.
I had my car towed to his shop. After diagnosing, it turned out the #1 and #3 pistons are both cracked, the cost to repair $9K. My car only has 32,000 miles on it!!!
Not only were my pistons cracked but the rod bearings had abnormal wear and needed to be replaced as well. Check out the burn pattern, heavy on one side and clean on the other. My rainy day fund just evaporated.
Really disappointed with MB, I have been driving only Mercedes for the last 30 years with ZERO issues on any of my cars. I will be signing up everywhere I can to get MB to pay for the repair.
Meanwhile I'm having to drive my convertible '03 CLK430 as a daily driver. That car just turned 60k mi and runs like a bat out of hell. "They don't make 'em like they used to..."
Now that I have pics I'll need to start the process against MB and NHTSA. I'll post what ever I find to help anyone who may have the same problems, please do the same....
Sorry to read about this, and best wishes for a satisfactory outcome, whatever it may be.
Further evidence that MB four bangers are to be avoided. Do not buy an MB with a four banger, for example the M274, M264 and M254 engines which are all related. The newer M264 and M254 engines have the charming characteristic of failing cylinder heads. These four bangers are found in A-, C-, E-, GLB-, GLC-, and GLE-Class vehicles in the North American market. Model years span roughly from 2015 until present.
It's so sad you are dealing with this, my personal observations are:
piston does look bad, especially on one side, looks like it was very hot in the cam and not equally speeded in cylinder as it's more on one side, with amount of soot it was accumulating it for some time. bad injector ? bad gas? low octane ? I would think. Very strange looking after 31K miles only.
Rod bearings, abnormal wear like this usually cause by wrong oil (spec) or long intervals. According to a Lab results for the oil I've sent to them after 4K and 3K miles,
it's already too thin at high temps. Used oil from 3 different brands, all 5w40 229.5
good luck with MB, I would report to BBB and consumer reports as they shows no major engine issues for 2018 year.
Good observations, strong possibilities.
I wonder if the Indy has been installing the wrong oil.
Which can contribute to LSPI, low speed pre ignition.
Which is killing Pistons in all brands.
2016 S550 sport, 2018 GLC300, M3, Zo7, 2021 Sierra Denali
Originally Posted by chassis
Sorry to read about this, and best wishes for a satisfactory outcome, whatever it may be.
Further evidence that MB four bangers are to be avoided. Do not buy an MB with a four banger, for example the M274, M264 and M254 engines which are all related. The newer M264 and M254 engines have the charming characteristic of failing cylinder heads. These four bangers are found in A-, C-, E-, GLB-, GLC-, and GLE-Class vehicles in the North American market. Model years span roughly from 2015 until present.
Our 2018 GLC300 is presently at the dealer for an electrical issue that they cant reproduce. Seems to be the accelerator pedal harness issue but the cant get it to happen for them. 2 weeks now. We have had the new GLB for 2 weeks. IDK what engine is in here but its a 4 cyl. What a piece of garbage this thing is. Our GLC is like a S550 in comparison ! LOL Wife can't wait to get her truck back. We take insane care of our cars and use the correct oil as I can subscribe to this being part of the issue. I race cars and have motors built and in anticipation of any detonation my builder uses a 2618 forged aluminum piston an an NA motor. Just amazing that MB uses a crap piston on a turbo motor. Granted pre ingnition and wrong oil may be the issue but a quality piston would not crack. Our sevice guy agreed he would not recommend any year 4 cylinder for long term ownership out of warranty. Said he has been getting cracked heads this year no pistons this year as years past. Said the GLE 3.5 motor was a safer bet......
Last edited by seamus2154; 08-29-2023 at 03:11 PM.
Our 2018 GLC300 is presently at the dealer for an electrical issue that they cant reproduce. Seems to be the accelerator pedal harness issue but the cant get it to happen for them. 2 weeks now. We have had the new GLB for 2 weeks. IDK what engine is in here but its a 4 cyl. What a piece of garbage this thing is. Our GLC is like a S550 in comparison ! LOL Wife can't wait to get her truck back. We take insane care of our cars and use the correct oil as I can subscribe to this being part of the issue. I race cars and have motors built and in anticipation of any detonation my builder uses a 2618 forged aluminum piston an an NA motor. Just amazing that MB uses a crap piston on a turbo motor. Granted pre ingnition and wrong oil may be the issue but a quality piston would not crack. Our sevice guy agreed he would not recommend any year 4 cylinder for long term ownership out of warranty. Said he has been getting cracked heads this year no pistons this year as years past. Said the GLE 3.5 motor was a safer bet......
Indeed. The M276 in both 3.5NA and 3.0TT variants is the only proven reliable MB engine in the past 10+ years. The only engine that might come close is the M113.
I will be signing up everywhere I can to get MB to pay for the repair.
Now that I have pics I'll need to start the process against MB and NHTSA.
I'll post what ever I find to help anyone who may have the same problems, please do the same....
2016 S550 sport, 2018 GLC300, M3, Zo7, 2021 Sierra Denali
For those interested, be aware that Mobile 1 0w/40 and 5w40 European formula is NOT a LSPI oil. It is a MB 229.5 spec oil and has been the easy go to for all Mercedes. If wanting to combat or insure yourself to some degree your oil spec needs to be a API SP rated oil to address the LSPI issue. Mobil 1 does make LSPI oil specifically designed for DI engines. On this motor just getting an oil change or using the trusted Mobil 1 Euro formula is not addressing the issue.
For those interested, be aware that Mobile 1 0w/40 and 5w40 European formula is NOT a LSPI oil. It is a MB 229.5 spec oil and has been the easy go to for all Mercedes. If wanting to combat or insure yourself to some degree your oil spec needs to be a API SP rated oil to address the LSPI issue. Mobil 1 does make LSPI oil specifically designed for DI engines. On this motor just getting an oil change or using the trusted Mobil 1 Euro formula is not addressing the issue.
Good post.
This is true of all internal combustion engines, not just one Mercedes four pot.
It's a universal problem. Oil manufacturers don't make a special formulation for one engine from one brand.
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by seamus2154
For those interested, be aware that Mobile 1 0w/40 and 5w40 European formula is NOT a LSPI oil. It is a MB 229.5 spec oil and has been the easy go to for all Mercedes. If wanting to combat or insure yourself to some degree your oil spec needs to be a API SP rated oil to address the LSPI issue. Mobil 1 does make LSPI oil specifically designed for DI engines. On this motor just getting an oil change or using the trusted Mobil 1 Euro formula is not addressing the issue.
Last month on my way to work I came off the freeway, pulled up to stop light and noticed a rough idle, the engine check light flickered. I made the left and pulled up to the next stop light, engine check light came on with a very rough idle. I made it to work and called my MB indie mechanic. He said don't drive it, have it towed to my shop, in it might be the pistons, I'm like WTF! He said he had replaced the #1 piston on a 2016 GLC 300 two weeks prior.
I had my car towed to his shop. After diagnosing, it turned out the #1 and #3 pistons are both cracked, the cost to repair $9K. My car only has 32,000 miles on it!!!
Not only were my pistons cracked but the rod bearings had abnormal wear and needed to be replaced as well. Check out the burn pattern, heavy on one side and clean on the other. My rainy day fund just evaporated.
Really disappointed with MB, I have been driving only Mercedes for the last 30 years with ZERO issues on any of my cars. I will be signing up everywhere I can to get MB to pay for the repair.
Meanwhile I'm having to drive my convertible '03 CLK430 as a daily driver. That car just turned 60k mi and runs like a bat out of hell. "They don't make 'em like they used to..."
Now that I have pics I'll need to start the process against MB and NHTSA. I'll post what ever I find to help anyone who may have the same problems, please do the same....
I have the same problem with my 2019 MBZ GLC 300 , 50,314 miles!
The same thing occurred when I was at a red light: ruff idling and check engine light came on. I got to an independent MBZ auto repair and they diagnosed it being a cracked piston #1. I soon found out that this is a very common problem with this engine and has been occurring since 2015 and MBZ is aware of the problem. I then had it towed to the nearest MBZ dealership. At that time I was 3 months and 314 miles out of the 4 year/50,000 warranty period (I'm the original owner). I took the diagnosis paperwork from the repair shop and the MBZ dealership charged me $300 to do their own diagnosis. Days later they informed me that they need to tear down the engine to fully see the piston #1 and any other engine damage. Now they want me to pay an additional $8549 so they can tear down the engine and examine the piston and engine, NOT repair or put the engine back together.
I do not have an additional $8500. I spent my money on this car for reliability since I am a senior citizen with a fixed income.
Please keep my updated everyone out there with this problem !
Thank you
I have the same problem with my 2019 MBZ GLC 300 , 50,314 miles!
The same thing occurred when I was at a red light: ruff idling and check engine light came on. I got to an independent MBZ auto repair and they diagnosed it being a cracked piston #1. I soon found out that this is a very common problem with this engine and has been occurring since 2015 and MBZ is aware of the problem. I then had it towed to the nearest MBZ dealership. At that time I was 3 months and 314 miles out of the 4 year/50,000 warranty period (I'm the original owner). I took the diagnosis paperwork from the repair shop and the MBZ dealership charged me $300 to do their own diagnosis. Days later they informed me that they need to tear down the engine to fully see the piston #1 and any other engine damage. Now they want me to pay an additional $8549 so they can tear down the engine and examine the piston and engine, NOT repair or put the engine back together.
I do not have an additional $8500. I spent my money on this car for reliability since I am a senior citizen with a fixed income.
Please keep my updated everyone out there with this problem !
Thank you
Sorry to hear of this situation. I hope things resolve themselves over time in the best possible way.
To my knowledge this is the first 2019 model year piston cracking report.
For those interested, be aware that Mobile 1 0w/40 and 5w40 European formula is NOT a LSPI oil. It is a MB 229.5 spec oil and has been the easy go to for all Mercedes. If wanting to combat or insure yourself to some degree your oil spec needs to be a API SP rated oil to address the LSPI issue. Mobil 1 does make LSPI oil specifically designed for DI engines. On this motor just getting an oil change or using the trusted Mobil 1 Euro formula is not addressing the issue.
Not only API SP but also SN Plus are for LSPI.
Mobile 1 0w40 seems to be SN plus.
Where did you see SN Plus for LSPI?
This is from API.org.
SP the newest standard for LSPI protaction,
I don't even see the SN Plus standard. Attachment 452137
castrol.comNEW API SN PLUS SPECIFICATIONS | WELCOME | CASTROL CANADAAPI SN PLUS provides a key benefit against low speed pre-ignition (LSPI), a catastrophic engine failure event that is caused by high pressure build up...
The API SN PLUS motor oil specification is intended to complement API SN and ILSAC GF-5 and aimed at addressing the increasing impact of Low-Speed Pre-Ignition in Turbocharged Gasoline Direct Injection (TGDI) engines.
The high pressures from turbocharging combined with direct fuel injection into the combustion chamber in these smaller TGDI engines makes them susceptible to a phenomenon known as Low Speed Pre-Ignition, or LSPI. While the mechanism of LSPI is not yet fully understood, research has shown that motor oil properties may be a contributing factor. Automakers can mitigate LSPI by adjusting the engine operating conditions, but in doing so inhibit some high efficiency engine operating conditions.
Amid growing concerns about LSPI among Automakers, the urgent need for a supplemental motor oil specification became evident. This new supplemental specification, known as API SN PLUS, includes the testing protocol for API SN and a special test for LSPI, the API Sequence IX test.
castrol.comNEW API SN PLUS SPECIFICATIONS | WELCOME | CASTROL CANADAAPI SN PLUS provides a key benefit against low speed pre-ignition (LSPI), a catastrophic engine failure event that is caused by high pressure build up...
The API SN PLUS motor oil specification is intended to complement API SN and ILSAC GF-5 and aimed at addressing the increasing impact of Low-Speed Pre-Ignition in Turbocharged Gasoline Direct Injection (TGDI) engines.
The high pressures from turbocharging combined with direct fuel injection into the combustion chamber in these smaller TGDI engines makes them susceptible to a phenomenon known as Low Speed Pre-Ignition, or LSPI. While the mechanism of LSPI is not yet fully understood, research has shown that motor oil properties may be a contributing factor. Automakers can mitigate LSPI by adjusting the engine operating conditions, but in doing so inhibit some high efficiency engine operating conditions.
Amid growing concerns about LSPI among Automakers, the urgent need for a supplemental motor oil specification became evident. This new supplemental specification, known as API SN PLUS, includes the testing protocol for API SN and a special test for LSPI, the API Sequence IX test.
I'm very calm ;-)
Currently im using Pennzoil but oil results came with high aluminum compare to Valvoline, Liqui Moly which I didn't like and I was searching for alternatives which are MB 229.5 and fight LSPI
I found Amsoil and others reporting you need API SN Plus or SP to fight LSPI, but I couldn't find any information on API site about standard SN Plus.
BTW if you search oil in Europe for GLC they are all API SP the same oil in NA all API SN
At least Liqui Moly and Motul
Mobil 1 has updated their spec sheets for 0W-40 and 5W-40 to be SN+ and SP compliant. Documents are dated September 10, 2023. Interestingly - 0W-40 is rated for 229.3 and 5W-40 is rated for both 229.3 and 229.5.
08-28-2023, 07:48 PM
