I bought a used 1995 940 Turbo last month, and started having a problem with it yesterday. As I was driving it I noticed that the temperature gauge was approaching the red (it's always stayed right in the middle before). I pulled into a Jiffy Lube that I happened to be near, stopped the car, popped the hood, and saw that antifreeze was boiling out of the overflow container. A guy who worked there said he thought the problem was with my thermostat, and offered to put a new one in for $15. There was an autozone just down the street so I went and got the thermostat and he put it in and filled the system back up with antifreeze. After turning on the car again, however, the needle was again approaching the red line. This time we noticed that the radiator fan wasn't on. I turned off the car and again antifreeze boiled out of the overflow container. When the car was cooled down a bit I started it up again and this time, after idling for a few minutes, the radiator fan turned on and the temperature stabilized. I was able to drive the 10 miles home without another overheating episode. This morning I started the car and let it idle, watching the temperature. After about 20 minutes the temp gauge started to go up again, and when it was a little more than halfway between the middle and the red line I cut the engine off. While the engine was on the radiator fan never started up, but as soon as I turned OFF the car the radiator fan turned on for about 10-15 seconds.

I just moved to a new town (Raleigh, NC) and I don't have a relationship with any mechanic here. Could anyone tell me what they think the likely source of my problem might be? Does it sound like it's the radiator fan relay? I think there's another, electronic thermostat, besides the mechanical one I had installed yesterday; is this right, and is this likely to be the source of my problem? Thanks in advance for the advice.

 

check to see if you do have a fan relay, also check the fans wiring as well.

 

Yes, I do have a fan relay, although maybe it's on the fritz. I brought the car to a mechanic today, and he said the cooling temperature probe, or some terminology similar to that, is leaking, and that that may be the issue. I'll post back on how things go

 

Your radiator may be pugged, and restrictng the flow. Check by seeing if it's uniformly hot all over. The fan temperature switch also may be bad even though they usually turn on or they don't....

 

check this one, http://www.howtodothings.com/automot...erheating.html
Severe overheating can often damage a good thermostat. If the engine has overheated because of another problem, the thermostat should be tested or replaced before the engine is returned to service. One way to check the thermostat is to start the engine and feel the upper volvo 760 radiator hose (or use an infrared noncontact thermometer to read its temperature). The hose should not feel uncomfortably hot until the engine has warmed-up and the thermostat opens. If the hose does not get hot, it means the thermostat is not opening and some are caused by a faulty fan clutch.