98 v90 overheated suddenly, troublshooting help PLS.

Lucasszy · Post by **Lucasszy** » 06 May 2007, 00:27

I drove my new to me v90 to San Francisco and all of a sudden after a hill there was water under the car and it instantly overheated.

I waited till it cooled, added coolant, but it did it again, and again!

The radiator is not leaking, but it keeps on blowing the coolant out around the expansion tank cap.

What could this be? The car has 150K. Could it be the

a) Thermostat (which I can replace on the spot, being 60 miles from home)

or

B) is it the water pump, and I need to tow the car home.

or

C) Is it something that I may be overlooking!

Please help, as I have to go back for the car in the AM, about 6 hours away!

Lucas

98 v90 150K

DanR · Post by **DanR** » 06 May 2007, 07:13

It could be the thermostat, but it also could be a bad hose. How old is the radiator, they can get gunked up and not cool efficiently. Also a bad t stat probably took out a hose. Look at all of the hoses, you have the one coming off the expansion tank, the lower and upper radiator hoses, the heater hoses, and the oil cooler hoses. If you are lucky if it is a bad hose, maybe the hole is near an end and shortening the hose and reclamping will get you home.

DanR 94 964 329,000 miles (95,000 on the new engine)

Lucasszy · Post by **Lucasszy** » 06 May 2007, 15:18

OK

I replaced the thermostat with a 180 degree unit and drove the car home 65 miles without a hitch.

Then I got to the local area and all of a sudden the car starts overheating again! Really bad! Cooland oozing out the overflow tank and spraying everywhere.

So I ruled out the thermo, should I flush the system to see how that would help?

Also, what is the best way to purge the system of air?

Could the system be clogged or something like that? I've read a few posts about this and it seems that this happens to other volvo owners, but no one has a definite answer as to why or how to resolve this.

Comments and suggestions would be greatly appreciated.

thanks

Post by **billofdurham** » 06 May 2007, 15:57

A thorough flushing, including back flushing of the radiator would do no harm.

Also, what is the best way to purge the system of air?

When the system is drained and refilled the heater control should be set on hot to stop air collecting in the heater. When you have refilled the system 'massage' the two large hoses, with the cap off, to disperse air pockets.

Bill.