XC 70 Cross Country Turbo 1999 Overheating

hottma_2001 · Post by **hottma_2001** » 19 Nov 2009, 18:45

My 99 Volvo XC 70 has starting overheating but only at random times. I noticed today that my fan did not come on at all. Usually, when I drive up a hill my fan will sty on for about 5 mintues after I turn off my car. It smells like antifreeze right before it overeats as well. Where do I start? Do I try the thermostat? Would that cause the fan to not work?

Post by **jblackburn** » 23 Nov 2009, 10:35

The thermostat only opens & closes to control the temperature of the fluid circulating through the system. It has no control over the fan.

I've only had my fan stay on after turning the car off once, and it was like 105 degrees outside, so I think that's kind of odd.

I wonder if you have an air bubble somewhere in your cooling system that's making it plug up (you say you notice an antifreeze smell). Is it bubbling out of the expansion tank? You could try bleeding the system and see if this improves anything.

There are several things that could be your problem with the fan not turning on at all though.

1) A bad Engine Coolant Temp sensor (right by the thermostat) will cause the fan not to come on, and other strange things to happen.
2) Bad fan relay. Try this first - try jumpering the leads to the fan directly to 12V and see if your fan comes on. Also, does the fan come on with the A/C?

I would not drive the car very much until you figure this out - these cars are very prone to blowing head gaskets if they overheat in the slightest.

I'd repost this to the 93-2000 850/-70 series section; you might get more help over there.