1990 300TE wagon - "swinging" temperature guage
 

Since my question about this was originally on a transmission post and not getting much information, I will start a new topic about this.

I am considering a 1990 300TE wagon. The owner has installed a new water pump, but the temperature guage will "swing" or as he says "dance" around. It will sometimes go about 3/4 of the way, but never stays there. He said it will go down when the heater is on (back when heat was needed). He said it has been like this for a while and he was told it was a sensor to the guage causing this. I am thinking though that if this was the case, why does it go down when the heater is on? I was told by a fellow Mercedes owner here that it could be a bad radiator, as the car is 15 years old.

Has anyone else ever had the "dancing" temperature guage issue? He said he is about to embark on a 5 hour trip in the car and will let me know how it goes. I just want to be sure it is not a bad headgasket. He said there was no coolant loss though, nor any oil in radiator, or water in oil, so I doubt this is it.

Thanks in advance.

temp
 

has the thermostat been replaced recently? you might start there first, try to get OE or equivelent.

Please just buy a Mercedes already!!!

Sorry that my posts cause you grief. I see from your # of posts and join date that you are fairly new here. This site is for people trying to get help with their cars, or potential cars. Sorry that my posts bother you. :rolleyes: They obviously are, from the remark and the little frown you put above it. :eek:

Thanks Carson- I will check to see if he has replaced that.

????
 

not shure what he is trying to say??

I think he is tired of me asking questions about the Mercedes I am considering. I thought that was what these forums was for. :confused:

My '88 TE temp gauge would run normal, then go max for a while, then normal, then max, etc. Bad ground, I think as I replaced the sender.

After you replaced the sensor, was it OK? He said it does go up, but comes back down and never really "settles" on a temperature. Does not really sound to me like a BHG (Head gasket) problem. It has been like this for nearly 3 months now and no problems.

Thanks. It is actually a car I am/was considering. He said it has "never went to the red" and it drops up and down, but never settles on a certain temp. He said he replaced the water pump, but no change. I am guessing it has been "swinging" more than normal - which is why he replaced the pump.