X218 OM642 very strange problems
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X218 OM642 very strange problems
Hi all, this is my first post, I would really appreciate your help, as no mechanic can solve this issue.
Car: 2013 X218 265 HP (OM642) with 187.000km
On most rides, the coolant temperature will rise to about 115 celcius when traveling on the motorway, which causes the car to kick in the fan at full speed and going to limp mode. This happens on 9/10 drives, but NOT always. On some drives, the car will be at around 95 celcius with no problems.
Sometimes, when doing kick down on the motorway, the car will go to limp mode and throw the code P0299 (turbo underboost). Previously, I saw some leaks from the seals around the turbo, they have been replaced. I don't know if these issues are related
I have no coolant loss, and the two water pumps seem fine. The thermostat was replaced to an aftermarket one about 3 months ago. Also the turbo was refurbished, and actuator replaced. The DPF was also removed as I thought this was the issue after running some time with a fully open thermostat. I checked my plastic swirl flap linkages, and they are nice and tight.
My boost pressure goes up to about 2500 hPa (36 psi), the exhaust back pressure to about 3500 hPa (50psi) according to Xentry. Coolant tempature 115 celcius
Could it be a defective ECU?
Thanks, Casper
Car: 2013 X218 265 HP (OM642) with 187.000km
On most rides, the coolant temperature will rise to about 115 celcius when traveling on the motorway, which causes the car to kick in the fan at full speed and going to limp mode. This happens on 9/10 drives, but NOT always. On some drives, the car will be at around 95 celcius with no problems.
Sometimes, when doing kick down on the motorway, the car will go to limp mode and throw the code P0299 (turbo underboost). Previously, I saw some leaks from the seals around the turbo, they have been replaced. I don't know if these issues are related
I have no coolant loss, and the two water pumps seem fine. The thermostat was replaced to an aftermarket one about 3 months ago. Also the turbo was refurbished, and actuator replaced. The DPF was also removed as I thought this was the issue after running some time with a fully open thermostat. I checked my plastic swirl flap linkages, and they are nice and tight.
My boost pressure goes up to about 2500 hPa (36 psi), the exhaust back pressure to about 3500 hPa (50psi) according to Xentry. Coolant tempature 115 celcius
Could it be a defective ECU?
Thanks, Casper
Last edited by casper0611; Jan 9, 2022 at 02:01 PM.
