When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
M274 Wrist Pins/Cracked pistons: Which engines are really affected?
I'm doing some research before buying a potential GLC300. Anyone have the latest updates on which motors were truly affected?
The reason I ask is that the original TSB from 2015 specified a range of motors up to xxxxx sequence that call out motors built thru March/April of 2015. (See TSB photo below) However, searching through the webs/forums there are several 2016, 17 and 18 MY vehicles that have had wrist pin failures. Shouldn't these MY's have the 'modified' wrist pins, since the issue was discovered before these 16-18 MY's were built?
There seems to be two updated TSB's released in 2016 and another one dated 2019. However, they seem to reference the same set of motors related to the 2015 build dates as mentioned in the original 2015 TSB below.
Question: This seems to be a US only issue. So, how many engine assembly plants are there? (Or suppliers of the faulty piston/wrist pins)
The engine coding shows the 'E0' variants and the '30' variants. Anyone know if this is reference to the engine plant?
Also, since this motor is shared with many Infiniti (Nissan) models there seems to be rumor that the Nissan engine assembly plants are responsible for many of the failed engines? (This wouldn't surprise me considering Nissan has become one of the worst automotive companies in the last 10 years.)
What's the real reason why the 2016-2018 vehicles have failures if they don't line up with the engine build dates from any of the TSBs? Did the old wrist pins get quarantined and then forgot about? Did someone find them and circulate them back into the build sequence?!?! Or, are the modified wrist pins faulty as well? What changed in 2019 MY engines that basically fixed the issue?
Screenshot is the 2015 TSB release. Below the screenshot is a link to the TSB dated 2019.
I'm doing some research before buying a potential GLC300. Anyone have the latest updates on which motors were truly affected?
The reason I ask is that the original TSB from 2015 specified a range of motors up to xxxxx sequence that call out motors built thru March/April of 2015. (See TSB photo below) However, searching through the webs/forums there are several 2016, 17 and 18 MY vehicles that have had wrist pin failures. Shouldn't these MY's have the 'modified' wrist pins, since the issue was discovered before these 16-18 MY's were built?
There seems to be two updated TSB's released in 2016 and another one dated 2019. However, they seem to reference the same set of motors related to the 2015 build dates as mentioned in the original 2015 TSB below.
Question: This seems to be a US only issue. So, how many engine assembly plants are there? (Or suppliers of the faulty piston/wrist pins)
The engine coding shows the 'E0' variants and the '30' variants. Anyone know if this is reference to the engine plant?
Also, since this motor is shared with many Infiniti (Nissan) models there seems to be rumor that the Nissan engine assembly plants are responsible for many of the failed engines? (This wouldn't surprise me considering Nissan has become one of the worst automotive companies in the last 10 years.)
What's the real reason why the 2016-2018 vehicles have failures if they don't line up with the engine build dates from any of the TSBs? Did the old wrist pins get quarantined and then forgot about? Did someone find them and circulate them back into the build sequence?!?! Or, are the modified wrist pins faulty as well? What changed in 2019 MY engines that basically fixed the issue?
Screenshot is the 2015 TSB release. Below the screenshot is a link to the TSB dated 2019.
All good questions. Also be sure to understand piston cracking behavior on this engine which affects up to 2017 model year, and I think 2018 model year failures have been reported.
All good questions. Also be sure to understand piston cracking behavior on this engine which affects up to 2017 model year, and I think 2018 model year failures have been reported.
I thought the loose tolerances of the wrist pins is what lead to the cracked pistons? Are there two separate issues that are not interrelated?!
I hade a 2018, C300 M274 that failed Cylinder 1 piston at 13,000 kms. Yes faulty wrist pins are well documented but I think it also comes down to mass production of sub-par rubbish piston head manufacturing. I have plenty modified 4 cylinder engines that pinged and knocked and were driven much harder in my younger days and never broke a piston.
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by davidijames
I hade a 2018, C300 M274 that failed Cylinder 1 piston at 13,000 kms. Yes faulty wrist pins are well documented but I think it also comes down to mass production of sub-par rubbish piston head manufacturing. I have plenty modified 4 cylinder engines that pinged and knocked and were driven much harder in my younger days and never broke a piston.
01-28-2023, 01:24 AM
