Replacing the Thermostat
on the 96 E320 (M104)
by Texholdem
2/6/08
Pictorial DIY - Thermostat replacement - 1996 E320
I decided to replace the thermostat because I am having bad fuel mileage (17-18 mix 65% highway 35% city) and my engine temperature won't go over 80C and I read somewhere that a bad thermostat may be the cause.
(Before that I thought cooler engine temp is good for the engine).
The job is simple for DIY rookie like me, just remove 3 10mm screws (# 1,2,3 on the pic) on the housing cover using a rachet with a long extension. That should be done on a cold engine.
Unplug connector #4 else the cable will be in the way when removing the housing cover.
![image](http://www.peachparts.com/diy/m104thermostat/01.jpg)
The cover and the old thermostat may sit tight perhaps because of the gasket sticking tightly, just use a little force. The spillage is minimal, about a cup of coolant.
Remove the thermostat and put the new one together with a new gasket in.
Attach the cover, start the engine and check for leak.
1: new thermostat
2: base of housing
3: housing cover, displaced
4: old (bad?) thermostat.
![image](http://www.peachparts.com/diy/m104thermostat/02.jpg)
hoping for some mileage improvement.
Discuss this DIY here.
-Texholdem
CategoryDiy