I have an 87 well maintained 240 wagon, auto. I bypassed the temp. compensation board, replaced the belts, overflow tank, and coolant temp sensor. It runs just below the red. Turning the heat on gives me heat, but little to no change in the temp on the gauge. The coolant is new. I replaced the 71c (160 degree) t stat with a 91c (190 degree) tstat. The fan clutch was replaced. Both radiator hoses are very hot to the touch with the bottom one slightly cooler. I'm at a loss, with my next step replacing the radiator. A flush is about 60 bucks, a new one is about a 100. Any ideas? Oh, the plugs look good, and the car was tuned up about 15k ago. Oh, and she is getting a new blower motor monday...ugh! it was just changed last year, but the resistor wasn't, so just some helpful advice, replace the motor, resistor and switch all at once!!! Blessings to all on this forum. Yall are wonderful.

 

May be blocked radiator. ("bottom slightly cooler") Should be the same temperature throughout the system...

 

thank you for your reply. I thought the bottom hose was supposed to be slightly cooler? the radiator felt uniformly hot but thats just using my hands. My opinion is if it IS plugged, a replacement would be better than the flush. for only about 40 bucks more.

 

switch back to the 160 degree t stat maybe

 

i tried that, it didn't seem to make a difference

 

water pump replaced yet? my fan clutch is going and that is why it is acting up....if you can spin it while engine dead it is done for but you said you put a new or used?

head gasket perhaps?

 

We think along the same lines. Head gasket is good. Fan clutch was replaced a few days ago. I put in a used one. It has some resistance when the motor is stone cold so I put in a new one. Its the same. I felt no difference so I returned it and threw on the used one. It never showed more then midline with the bad compensation board. I either need to put in a known accurate gauge or a new radiator

 

I read up about this a ton cuz I am having the same issues. Replaced everything but the RAD. Drilled out the thermo so it free flows antifreeze. My next step is to replace the RAD and from what I've read it's probably the solution. Volvos seem to be iffy when it comes to the cooling system. A new RAD is almost as much as a professional flush however you can do a flush yourself.

 

true, but a flush may not work, and you will still need a new rad. then you've effectively doubled your cash outlay for a fix. A new rad will 100% for sure be flowing completely free and clear.