W211 1.8 Kompressor Thermostat

Page may contain affiliate links. Please see terms for details.

Jimmas

Active Member
Joined
Mar 9, 2018
Messages
141
Location
Stevenage
Car
W204 SE 2009
Hi Guys
First post here, I have a 2006 W211 1.8 Kompressor which has developed a very low reading on the temp gauge, I am thinking thermostat, also the fuel economy seems to have taken a dip, my question is has anybody changed on on these engines and are they relativly easy to do? any help appreciated.
 
Assuming yours is the M271 engine, then yes I have done this. It's a Wahler thermostat, located right at the front of the engine.

The trick is to syphon-out the coolant from the expansion bottle first in order to minimise coolant lose, and if possible (but not mandatory) also raise the front of the car so that the thermostat hose at the front is higher than it would normally be.

The thermostat housing itself is secured to the front of the engine by two bolts (Torx, from memory), undo these and undo the securing clip for the hose, and then the thermostat housing needs to be prised out - be careful, its plastic on aluminium so gentle does is.

The thermostat is then a straight swap. Refit the housing but do not over-tighten the bolts.

You can then reuse the coolant as its good for 15 years - as long as it is in good condition and you use a clean container to collect it.
 
Assuming yours is the M271 engine, then yes I have done this. It's a Wahler thermostat, located right at the front of the engine.

The trick is to syphon-out the coolant from the expansion bottle first in order to minimise coolant lose, and if possible (but not mandatory) also raise the front of the car so that the thermostat hose at the front is higher than it would normally be.

The thermostat housing itself is secured to the front of the engine by two bolts (Torx, from memory), undo these and undo the securing clip for the hose, and then the thermostat housing needs to be prised out - be careful, its plastic on aluminium so gentle does is.

The thermostat is then a straight swap. Refit the housing but do not over-tighten the bolts.

You can then reuse the coolant as its good for 15 years - as long as it is in good condition and you use a clean container to collect it.
Thank you for replying, I will get a stat from the local Mercedes dealer and change it, hopefully it may improve my MPG once it is running at the correct temprature.
 
The video shows the thermostat housing actually broken at the point it goes into the cylinder head, he calls the broken bit inside the "thermostat spacer" it's actually the neck broken off.
Be very wary about prising it out, I found leaving the hose in place allowed a little more leverage to slowly turn the housing from side to side before trying to pull it out, it takes a bit of effort so don't rush.
The two O rings that come, the square section one goes on the thermostat end and the round one at the other end. A few drops of washing up liquid to lubricate the housing make it easier to slide in.
 
Thank you guys for all your help, I will let you know if when replaced it solves the problems.
 
Assuming yours is the M271 engine, then yes I have done this. It's a Wahler thermostat, located right at the front of the engine.

The trick is to syphon-out the coolant from the expansion bottle first in order to minimise coolant lose, and if possible (but not mandatory) also raise the front of the car so that the thermostat hose at the front is higher than it would normally be.

The thermostat housing itself is secured to the front of the engine by two bolts (Torx, from memory), undo these and undo the securing clip for the hose, and then the thermostat housing needs to be prised out - be careful, its plastic on aluminium so gentle does is.

The thermostat is then a straight swap. Refit the housing but do not over-tighten the bolts.

You can then reuse the coolant as its good for 15 years - as long as it is in good condition and you use a clean container to collect it.
Thanks good info regards magsbert
 
Thank you for replying, I will get a stat from the local Mercedes dealer and change it, hopefully it may improve my MPG once it is running at the correct temprature.

Will definitely improve your MPG, petrol engines run richer (more fuel injected) before reaching normal operating temp. But take note that it's also the same case with colder air intake temps and it been the cold season your MPG may be a little off from your warmer recordings, not by much but still worth mentioning
 

Users who are viewing this thread

Back
Top Bottom