Mercedes-Benz Forum banner

Operating temperature and cooling fan

761 views 0 replies 1 participant last post by  jookul 
#1 ·
Hi Guys
I'm hoping someone can help me or with this. So my car is a S350 2006 Right hand drive irish spec.

My problem is to do with ooperating temp and my cooling fan. I have searched this form and the Web and can't find a definite answer.
When is start my car from cold and do my usual commute about 20 miles into town my temployer. Suits between 87 and 92. it is fairly steady and doesn't cause any concern. Any when I get into town on this drive it also sees quite steady. My problem occurs when I leave town after driving I traffic for a while abd head out back onto the open road. My temp will hold stay for a few mins and then start dropping to 80 from about 92...them it does up at built then back down and then after doing this a couple of times it will settle back down.this worries me a bit as I can't remember the car doing this hunting before.

The other thing I noticed is I think a problem with my cooling fan. While I was trying to figure out what is going on with my temp I plugged in a live data stream middle into my OBD port to monitor te temp there while referring to the temp gauge.with the car parked on level ground outside my house I bribed that the cooling fan came on at about 96 degrees according to the obd reader and the temp Guauge was reading about 92. It did this a couple of times so I was kinda happy with that. When the fan came in it was running at about low to medium speed. Bear in mind the car was only idling at at this time. So I took the car out for a quick die to see what the temp would do and after about 1 mile of a steady drive my gauge went down to about 85 and obd was reading about 80. So I came back and park the car on a hill so the car was facing up the hill. I left it idle and I noticed about about 5 mins that the temp gauge was reading about 95 and odb 104 and the collar fan had not come on. So I got a bit concerned as I'm think if you happened to be stuck on a hill facing upwards you could potentially overheat. So quick drove my car back onto level ground a distant of about 20 yrds and when I got out of the car tge cooling fan had come on as was cooling the engine.

This semi wally odd that the fan would only come on while on level ground.

Does any of this sold normal. I am struggling to find the correct operating temp for the car. Some people say bang on 90 and should never move (I am kinda aiming for that) sone say between 80 abd 100 some say between 85 and 95...I'm not sure which it should be.

And that problem with the fan seems really strange

We have just changed the termostat to no avail. I have a new coolant temp sensor to be fitted at the back of the engine but I don't think it is that. Some people suggest the fan module but that is an expensive repair so I don't want to go there without stronger evidence
There are not my S350 on this forum or across the Web trying to do a like for like is difficult.

Does any of what I said sound normal or problematic. Or am I chasing a ghost.

Any help or guidence would be greatly appericated

Cherrs
 
See less See more
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top