Hey guys...I'm having a slight cooling issue on my '88 240. What happens is sometimes (not always) the the temp gauge gets really close to red then will drop a bit, go up to almost red again then drop, etc. Most of the time it says right in the middle but, does this sometimes. When this happens, it doesn't matter if I'm moving or stopped so, I'm ruling out the fan clutch and thinking the thermostat is the culprit. I don't have any records from the car and the guy I brought it from (only owned it for a year to learn how to drive stick on) didn't get any from the previous owner so, I don't know when anything was replaced but, the radiator, upper and lower hoses as well as the water pump look pretty new. What do you guys think?

 

I would replace the thermostat and search this forum for "temperature compensation board"

 

Thanx Bubba...Wasn't aware of that temperature comp board problem.