Volvo won't heat up to normal temperature

Jmccarthy2 · Post by **Jmccarthy2** » 03 Jan 2013, 18:38

Have 2004 s80 won't heat up to normal operating temperature. Have changed thermostat, coolant temp sensor not sure what to do next. Any ideas?

Post by **JimBee** » 03 Jan 2013, 19:03

Did you install the correct t-stat from Volvo?
Does the engine otherwise run well?
Are you sure your coolant level is where it should be? Does the engine actually seem cool to the touch?

If the coolant level is right and the engine seems cool to the touch after running for 5 to 10 minutes, it seems like the t-stat must be stuck open. One member here said he's seen brand new t-stats malfunction. You can put it in a pan of water with a thermometer, heat the water and watch for when it opens.

Although I haven't heard of it happening, it's possible the water pump impeller could have broken loose and isn't circulating the coolant. That would not be good. I think you'd hear the top engine of the engine crackling from excess heat buildup if that were the case.

Most likely though, it's the t-stat.

Jmccarthy2 · Post by **Jmccarthy2** » 04 Jan 2013, 08:38

All fluids are good it does heat up if your not moving once I start moving temp drops. Did put ome thermostat in. What about temp sending unit? Does run good

Post by **mikealder** » 04 Jan 2013, 11:05

Is the rad cooling fan running all the time as the ECU will switch the fan on to full speed if it's not happy with the way the engine temp builds up, it should put the check engine light on if this is the case, worth a check though as the increase in airflow when moving with the fan running will cause the temp to drop. This fault usually triggers a P0115 fault code so you might want to scan the car for codes and reset it - Mike

Jmccarthy2 · Post by **Jmccarthy2** » 05 Jan 2013, 10:01

Fan dosnt run all the time did put black duct tape over grill and does help with getting it to climb to two bars below middle bar where it should be but still won't stay at highlighted bar where before I had the problem would stay.Did reset all c,odes did hear something about ac not working correctly having some thing
To do with it. My ac will work if I'm moving but if I'm not moving wont

produce cold air then when I start moving again it starts to cool??

jeremyshoglund · Post by **jeremyshoglund** » 06 Jan 2025, 05:47

Did you ever figure it out? Same problem here.

Post by **scot850** » 04 Feb 2025, 21:04

When it is really cold, try zip-tying carboard over the hood grille. Don't run over say 40F in traffic and see if it helps the car warm up.

Neil.