Over the winter I've got a CEL, and the code told me Engine Temp Too Low (my MPG were also worse than usual), so I opened the hood and checked the thermostat, here's what I see:



Am I looking at a thermostat + hose replacement? I read on the forum, If it's just an o-ring or clip issue with the hose, I can just change those. Does anyone know the part number for those (2009 W211 E350)? And how much coolant do I need for a thermostat + hose job? Thanks!

 

Well your in a pickle the o ring and gasket are VIN dependant--the thermostst is 272 200 04 15---but you should use the VIN to also check!!

 

Replace hose, those crimp fittings wear down over time especially if the hose has been removed from the t/stat multiple times.