New Thermostat? 2006 Volvo S60

Jocelyn198 · Post by **Jocelyn198** » 22 May 2011, 08:39

Hi-
I have written in a few times about my cooling fan that is runs constantly while the car is on. The cooling fan module was replaced as well as the cooling sensor and the fan is still running! We brought it to a new mechanic who thought that it might be the thermostat. The car is not overheating but he mentioned that the top tube on the radiator was running especially hot. He also thought that the coolant level was too high. I thought that when the thermostat was bad the car would overheat....any thoughts? Is there a sensor that could cause the fan to run and the radiator to act like it does??

Post by **jimmy57** » 22 May 2011, 10:56

The fan runs when you turn the key on cold engine?
Has the car been checked for codes?
Does the engine start and run well when cold and hot?

Jocelyn198 · Post by **Jocelyn198** » 22 May 2011, 11:27

Yes-fan runs when the key is turned on and the engine is cold.
The first mechanic mentioned that he checked for codes but they didn't tell him anything-he is a foreign car mechanic but not specifically a Volvo mechanic. I should probably just take it to Volvo.
Yes-engine runs great(hot and cold). The fan just runs all of the time. The radiator is hot but the temp gauge in car stays in middle. Check engine light is not on.

el diablo viejo · Post by **el diablo viejo** » 22 May 2011, 12:39

The little I have learned about this subject so far as relates to my S 70:
1) Was the new coolant temperature sensor an original equipment Volvo part? The aftermarket ones do not work reliably.
2) Was the battery disconnected after changing the sensor to clear the codes ? (Make sure you have the security code to reset the radio before disconnecting the battery)
3) The thermostat may still be the problem but again replace only with OE.

Resident experts on here probably have other tips and/or questions.

Post by **jimmy57** » 22 May 2011, 17:05

If fan is on immediately on cold engine you can forget a thermostat problem.
Strange one. If the temp sensor or its wiring was a problem you would almost certainly have had some cold driveability problems.
A/C pressure sensor could be delivering high pressure reading and making it run. That would be verified by a scan tool that display engine computer data values. The A/C (air conditioner) pressure will change with temp and will go down when switched off.
It is conceivable the sensor could fail in a way to deliver a fixed signal that would be indicating a pressure where fan is needed.

volvodoc · Post by **volvodoc** » 24 May 2011, 12:03

06 should have the new style t-stat that comes as a assembly housing,t-stat and sensor if the sensor shorts the ecm turns the fan on as a precaution to protect the engine a special lon torx bit will be needed to get to the bottom bolt good luck

Jocelyn198 · Post by **Jocelyn198** » 24 May 2011, 20:42

Good to know! Thanks. We are bringing it to Volvo tomorrow-hopefully the issue will finally be resolved.

millsa99 · Post by **millsa99** » 12 Jul 2011, 22:18

Did you resolve this problem? My radiator fan is on the whole time now too.