I need some feed back, I have an 88 240 DL, brand new radiator, new thermo, and it is still overheating. I checked the fan today when the car was warm and it moved pretty easy, it didn't exactly spin but it didn't have much resistance either, however I am wondering if that is the actual problem, cause it overheats driving and at a stop, and with no AC on, and it never smokes or acts like it is overheating??? Does anyone think it might be the coolant temp sensor???? Any ideas would be great!!!

 

The fan should not move easily when it is hot.

 

Do you see the coolant circulating when you look inside the coolant reservoir ? If not, possibly a failed water pump. May also be a bad thermostat. Remove it then drop in some hot water and see if it opens. There is nothing fancy about the cooling systems here so the reason shouldn't be too hard to find. Let us know what you find.

 

Thanks I will check the coolant reservoir and see what it does, I just replaced the thermostat, so I don't think that is the prob, I am hoping to avoid having it be the fan clutch, hoping something else (cheaper) will be the prob!!! Thanks again and will keep you all posted

 

Does the car run hot at highway speeds? If so...it ain't the fan clutch. Water pump, thermostat (new ones can be d.o.a.), air bubble near the thermostat or head gasket. Is the radiator new...or just new to you? Pretty tough to see into a Volvo rad. I really haven't ever seen any circulation going on in a coolant reservoir. When the system is pressurized there is equal pressure on both the large hose and vent hose for the most part...wouldn't count on that as a diagnostic tool. If you're near a Harbor Freight, they have infra red heat guns that can take the radiators temperature...see if it's actually too hot. If it only runs hot in stop and go traffic or at low speeds then it's generally the fan clutch.

 

Yes, you really need an external thermostat to define running hot.
And as said above, a fan clutch on an engine at running temp should be quite stiff to turn. You should be able to hear a fan clutch speed up as the viscous coupling engages if it's hot enough.
A great trick to check if a fan clutch is working is to get the engine/radiator hot, shut it down and check the clutch resistance, then hose down the fan clutch and check again, if there is no noticeable difference, you have your problem.

Regards, Andrew.

 

Ok, so it does run hot also on highways speeds....I did check the coolant reservoir and did not notice anything moving, or circulating in there, the radiator is new to the car...I have an IR gun that should work also to check the radiator right??? I am thinking maybe something that has to do with thermo, when installing those things is there anything special I need to know??? My husband installed the new one and he may not have done all the steps??? Just kinda weird, cause there are times that it runs at just the right temp, but most the time, no matter speed or stop and go it the temp gauge runs hot??? Thanks again for all your help!!!!

 

Andrew,

That's a great idea!

Thanks

 

It sounds like at the very least you need to check the fan clutch and also re-check the thermostat installation. If the car is running hot most of the time it sounds like the thermostat itself is either backwards or faulty.