Hello all,

I'm looking for some advice on a intermittent problem.
A few weeks ago, I saw that my temp gauge was leaning more toward the hot side. It was somewhat close to the red line. I checked the coolant resevoir and it seemed low, so I topped it off with a Prestone 50/50 mixture.

Everything was normal until yesterday.

I took a round trip (approximately)200 highway miles and then about 4 hours of NYC stop and go city traffic. While stopped in traffic, I noticed that my coolant gauge was leaning toward the red line again. Got worried, turned on the heater full blast and it went back to normal. Later on (about 20 mins later), same thing.

Seeing that it was about 40 degrees yesterday, I'm concerned about this.
Any thoughts? Is it time for a new radiator?

--
1998 Volvo S90 17" C70 wheels and only 50K miles. Long way to go!!

Replace the coolant reservoir cap.

DEWFPO
--
1998 S90 071,245 and 1995 964 154,100

Probably not a bad idea. I was flushing the tranny in my new-to-me '94 960 (80K mi from Florida) last night and when I glanced at the coolant reservoir I noticed small cracks around the top part of the cap. I went out to a 240 parts car out in back of the shop and grabbed it's cap which appeared to be in good shape. The cracks in the cap didn't seem to cause any problems, but I wonder if they would have if I didn't replace it...
--
Chris. Halifax N.S. '98 V90 > 195K km, '94 964 > 80K mi. SOLD: '91 745T > 301K km (and no, I don't know why I sold it.) and '91 745 NA > 411K km (I miss her).

Start small. Replace the thermostat and flush the cooling system. If your low coolant light didn't come on then you probably don't have a coolant leak. Having to top off the cooling system once in a while is perfectly normal.
Also in stop and go traffic or when the the temp gauge is over the half way point, can you hear the cooling fan cycle on and off?
This engine doesn't take kindly to over heating. You might have a clogged radiator if you car was routinely topped off with tap water, but you should start with the cheaper normal maintainance items first.
Good luck
Justin

Thanks for the recommendations. I will try those things.
Today I drove again round trip (the same trip from NYC to Philly) and no peaking on the temp gauge. It stayed pretty much in the middle.I also topped off the coolant before leaving for the trip.
Thanks again for the advice.
--
1998 Volvo S90 17" C70 wheels and only 50K miles. Long way to go!!

Hey guys,

are the thermostats hard to replace on these cars?
I've never done any under the hood work on this car (it's been relatively dealer serviced). They're beginning to become a little pricey.
If it's something I can do, I'll try. I just neeed a little guidance.

Thanks in advance.
--
1998 Volvo S90 17" C70 wheels and only 50K miles. Long way to go!!

The thermostat's are easy to replace and not messy at all. Just don't strip the two torx head bolts holding the upper hose goose neck on.

Drain about 2 qts of coolant from the radiator (w/reservoir cap off), then use a good quality torx head socket and evenly loosen each bolt, replace the thermostat in the EXACT same orientation with the rubber "C" gasket sliped over the circumference of the thermostat. No sealant needed. Replace the thermostat, evenly torque down the two bolts, replace the coolant, and put the cap back on. You might loose anywhere from a few drops to a tablespoon of coolant at most.

Hints :
- The drain cock for the radiator is on the passenger's side of the radiator.
- When you remove the gooseneck (with the upper radiator hose still attached) be careful not
...to overstress the upper plactic neck on the radiator. They are know to crack from stress.
- Use a Volvo OE thermostat. It's about $14 and the gasket is included. The Volvo OE thermostats
...fail OPEN, not closed.




DEWFPO
--
1998 S90 071,245 and 1995 964 154,100

Hey guys,

I wanted to give you an update regarding my problem.
It turns out that I had a small crack in my radiator. Also my sensors were screwed. I had all of it replaced and it looks as if she's running back to normal.

Thanks again for all of your help!
--
1998 Volvo S90 17" C70 wheels and only 50K miles. Long way to go!!

Do you remember which sensors you had to replace

Thanks for letting us know what the problem(s) turned out to be.

DEWFPO
--
1998 S90 071,245 and 1995 964 154,100