ph2426

Hi all,
I have a 2015 E63S Wagon and something quite funky is going on. There is a yellow coolant light on the dash periodically but the temperature stays between 190 and 195 and the coolant level is correct. Today I have noticed the fan keeps turning on periodically even though I haven't driven the car for 7 or 8 hours. Does anyone know what this could possibly be? I am not even sure where to start looking in these forums. Thank you in advance for any insight.

ph2426

This is the warning I see and I cannot find it in the owners manual.

Mojo20032004

Judging by the gauge, looks like your thermostat might be stuck. Should be over the half way marker.. Also check coolant levels

OldManAndHisCar

I had the same thing (only I have a much larger E63 as opposed to your tiny, pathetic E62 ;-)

After I replaced my coolant tank the issue went away...then, well, my other issues that I had just posted about.

kenneyd

Quick scan with xentry should show you exactly the fault, without the scan, can only assume that it's likely a coolant sensor or thermostat issue.

ph2426

haha sorry I just realized my error!

ph2426

Thank you all. I actually just changed the expansion tank myself a few weeks ago and the coolant level looks ok. Could it be the plug that goes into the tank at the bottom? Would that cause the yellow warning and the fan running?

ph2426

I unlocked my car this morning and it had been sitting all night and the fan started running immediately and also ran about 5 minutes after. I have not turned the car on yet. Has anyone seen this?

PeterUbers

do you have the always on IC pump mod?

ph2426

forgive my ignorance but I don’t know what that is.

OldManAndHisCar

Yes, in a car with a bad thermostat or bad sensor. It already thought it was hot....while your car is a bit heavy, it takes a special kinda fat pig to think it is hot before it is even started ;-P

ph2426

haha thanks all! Should I go ahead and swap the thermostat myself or is it best to take it in to have the codes read? thanks!

Baltistyle

if you did not have this light before you replaced the expansion tank, I would think that perhaps there is air in the system. Are you checking the coolant in the morning before starting? Are all sensors plugged back in. Was the tank changed with or without vacuum/ pressure assist? If it’s the thermostat, doubly check the part number as it changed at some point in the w212 and marries to the water pump.

definitely get the codes read before any work. Thermostat is diy, but not fast.

ph2426

Thank you! I took the car in today and they found the fan module/ assembly had a ground fault and needed the fan to be replaced.