Did I break the Engine temp sensor? (pic) - PeachParts Mercedes-Benz Forum

Bstef · #1 06-07-2007, 03:59 PM

Dropped a wrench- knocked the wire out of this thing...
Going to have to solder it to get a good connection...

Is this the main engine temp sensor?

Im don't want to turn the car on till I know what it is...
Can't find it labeled in my Haynes manual....

Thanks for learnin me.

compress ignite · #2 06-07-2007, 04:07 PM

If the wire is already separated,try grounding the wire onto the engine to see
if the "temp" gauge moves.(with the key in the "on" position...engine OFF)

sometimes the wire when separated gives a different signal to the gauge (no
ground) I can't remember which the 617XXX engines use.

If you affect the gauge with the wire off or grounded,You have your answer!

Douglas.Sherida · #3 06-07-2007, 04:13 PM

It is a coolant temp sensor, but not "the" coolant temp sensor.

The one that drive the gauge on your instrument cluster is in the left side of the engine block between the second and third glow plug (first and second? I don’t remember).

I honestly don’t know what that temp sensor does, but I’ll hazard a guess that it feeds info to the climate control. Someone will chime in with the right answer I'm sure.

Bstef · #4 06-07-2007, 04:41 PM

Thanks guys.

I've jammed the wire back in and taped it for now.

When I tested it there was no difference,
naturally as it is apparently the coolant temp.

So is this the coolant temp gauge that helps add/remove vac
to keep shifting the same weather hot or cold?

I was having hard shifting cold and smooth hot.
That cable could have been lose before and not active,

Im going to go take a spin and see if theres any difference...

before I ask about replacing it to fix the hot/cold shift difference...

{Im not going to be able to testdrive today. I live in chicago and If i move my car from the street- I will not get parking again (streets are full past 4pm- 44+ cars on the street on every block) and I don't feel like paying a meter tonight every hour till 9pm to park. I did that yesturday.}

Ill check it Friday.

bgkast · #5 06-07-2007, 10:27 PM

I believe that turns on the electric fan.

TMAllison · #6 06-07-2007, 11:23 PM

I can confirm that on my 85 that wire has previously been pulled out, stuffed back in and that the temp gauge still works. Dont know about the aux fan question as it's AC died long ago.

pawoSD · #7 06-07-2007, 11:27 PM

It sends a signal to the climate control unit to allow the blower speed to increase once the engine coolant is to a certain temperature. (so it doesn't blast you with cold air when starting the car on cold mornings etc...) The aux cooling fan is controlled by a temp sensor on the receiver dryer of the A/C system....and also by a sensor by the radiator on some cars....