Code P0128
Thread Starter
Junior Member
Joined: Dec 2008
Posts: 46
Likes: 0
CLS 55 AMG
Code P0128
I get the classical Engine light. After connecting to OBD II I got code P0128. My thermostat indicate more than 80 degrees. I search the forum but did not find anything how to replace the thermostat on R-350, 2012 Gas engine. Is any directions or anyone can upload some pictures? 
MBWorld Fanatic!
Joined: Jun 2006
Posts: 1,140
Likes: 118
From: Nova Scotia, Canada
2023 GLK250, 1987 560SL
R350 has the M272 engine, so it's the same for any model with that engine. The thermostat is located top front and centre on the engine - I would check it with an infrared thermometer to make sure it's actual the thermostat and not the temp sensor that's gone bad.
Thread Starter
Junior Member
Joined: Dec 2008
Posts: 46
Likes: 0
CLS 55 AMG
easy instalation
I end up replace the thermostat was real easy job. Did not drain all coolant as per Mercedes benz parts I was told that the antifreeze has no span life you can reuse it. I just drain enough from the radiator plug in buttom and then I add some more. I end up removing oli filter for fitting new thermostat.
Thank you
Thank you
