Was driving my wife's '07 E350 in 10 deg F temps and noticed the temp gauge only got a little above 60 deg C.


I could have sworn it always hovered around 90 to 100 no matter what the outside temp was before (but I could be wrong).


Do I have a thermostat hanging open (or opening early), or is this normal and just my memory is out of alignment.


If it is the T-stat, how hard are they to change?

 

I'm confused as to whether you're referring to to F or C. Sometimes the little thermostat thing pops out of the holder and messes up the reading.

 

He says 10 deg F. My car takes 15 min and 5-7 miles to get above the 80 line when is between 0-5 F outside. Tstat can be going bad. When mine was not working properly I noticed temp changes depending on driving - when I stop at stop light temp goes up and when I start driving will start dropping.

 

Outside temps in "F" as is customary in the US, and engine temps in "C" as shown on the dash.

 

Each drive was a bit over 30 min. There and back with a good cool off in between.


It got a little closer to 80 deg C when I pushed it, but the drive was mostly at 35 to 45 MPH on suburban roads.


Never crossed the 80 mark, and I swear it always settled above that after 5 min or so of driving.


SO on to the second question, how difficult is the T-stat replacement.


Saw a video on an '08 C-300. Is it the same?


Do you really need to remove the air pump, belt and idler?

 

This just happened to me last week in our single digit high temps where temp light did not go over 60 Celsius, then CEL.
Thermostat replaced. Car warms far more quickly now, even than it did earlier in the fall. So thermostat was probably hung open for some time, but it took the very cold weather to notice.

 

Wife reported that yesterday it did not get over 60 Deg C, and the CEL came on. I did not get a chance to read the code, but ordered the parts and am hoping for a warmish day to do the work.

 

Code was as expected P0128, coolant temp low.


Still gets near 60 Deg C.


Parts come in next week.

 

Got it changed.


2 1/2 hours in a cold garage.


About 1/2 hour was because it was the 1st time under the hood of this car.
About 1/2 hour was finding the right tool with my garage a mess.
About 1/2 hour was waiting for it to warm up to double check everything at 33 deg.


Next time on a warm day on the drive way will be a 1 to 1 1/2 hour job.