97-850 GLT overheats with A/C on

Mike850glt · Post by **Mike850glt** » 22 Jun 2012, 09:52

So I have a 97 850 GLT. Great car, however I am having issues with the car overheating when the A/C is on. I recharged the compressor and it has held the charge for a few weeks. I can hear the compressor kick in. Yet the A/C will blow either warm air or cold air but the car starts to overheat. Any suggestions are appreciated.

Post by **jblackburn** » 22 Jun 2012, 10:03

Radiator fan working when the AC is turned on?

Mike850glt · Post by **Mike850glt** » 22 Jun 2012, 10:20

Yes the Fan works it even stays on for a while after the car is shut off if the A/C was running

Post by **jblackburn** » 22 Jun 2012, 10:31

Hmm...the problem may be two-fold. The fan is running after shut down because the car really IS getting too hot.

Yet the A/C will blow either warm air or cold air

Sounds like the classic Volvo clutch-gap issue. Search the site for a discussion and repair procedure using bread-clips to shim the compressor clutch.

As far as the overheating, on a turbo model, you've got the radiator sandwiched in between the intercooler for the turbo and the condensor for the air conditioner in the front. That means a LOT of heat.

Has your radiator ever been replaced? If so, I think it may be because it's an aftermarket model with less-than-adequate cooling; if not, it may have "fin rot" (fairly common on cars that spend their life in Northern winters) or clogged passages that have degraded its cooling capacity to where it's no longer sufficient.

Mike850glt · Post by **Mike850glt** » 22 Jun 2012, 13:41

1 thing I should have mentioned is I have a small leak from the radiator expansion tank. Can the drop in the coolant pressure be causing the over heating issue?

Post by **jblackburn** » 22 Jun 2012, 13:44

Under normal driving (AC off), the system will sometimes not activate the fan if it doesn't reach the pressure it's supposed to.

Though, the fan should be running to cool the condensor for the air conditioning anyway, so I wouldn't think that should be overheating the engine ONLY when the AC is turned on.

Post by **MoVolvos** » 22 Jun 2012, 19:37

Mike850glt wrote:1 thing I should have mentioned is I have a small leak from the radiator expansion tank. Can the drop in the coolant pressure be causing the over heating issue?

The cooling system needs to hold pressure in order for the system to cool properly.

PV=nRT
http://en.wikipedia.org/wiki/Pv%3Dnrt

When Temp rises and Volume stays the same the Pressure will go up. If the Pressure is not holding the Coolant get boiling mad for Pressure not doing it's job and expands everywhere. Not exactly but sort of.

Blessings,
BKM
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Mike850glt · Post by **Mike850glt** » 29 Jun 2012, 16:15

So now the car overheats under normal driving conditions without the AC on at all. I got the leak fixed and it’s still overheating. Can it be the thermostat?

Post by **MoVolvos** » 29 Jun 2012, 23:06

Mike850glt wrote:So now the car overheats under normal driving conditions without the AC on at all. I got the leak fixed and it’s still overheating. Can it be the thermostat?

This maybe helpful!

How To Tell If Your Head Gasket Is Blown

Fixing Tough Head Gasket Leaks (If It Is?)

Member JWHunterinTN here had Steel Seal work for a year. Yours do not have any oil so it may work and last even longer
https://www.matthewsvolvosite.com/forums ... =9&t=47929

Blessings,
BKM
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Post by **jblackburn** » 30 Jun 2012, 07:56

How long does it take to overheat? Does the needle pin to the red or does the tank just start overflowing within a few min of running?