Engine Temperature drop while cold weather driving

gditsch · Post by **gditsch** » 27 Dec 2010, 08:22

We just bought our first Volvo this past summer, a 1998 V70. On our trip to visit family I noticed that when traveling down the interstate the engine temperature would drop and it would get cold inside. This is the first trip the car has made, as it normally is a car to drive around town, and it's my wife's car. She just told me that when "it's really cold, it never heats up?"

I noticed that if I'd pull over for about 3 to 4 minutes, the engine temp gauge would move back up to almost the middle. From what I've learned on the forum and site, it appears that I may have a thermostat stuck open:

https://www.matthewsvolvosite.com/forums ... =1&t=19190

My question: I have a 7 hour drive home today. Can I safely drive home and fix it there, or should it be done prior to traveling? I know if it was too hot, I'd need to stop right away... but not sure about this situation.

Post by **jblackburn** » 27 Dec 2010, 08:26

You can drive it no problem; you'll just be cold, and your car will use a bit more gas than usual.

When you get home, replace both the thermostat and ECT sensor, as the ECT sensor tends to stop functioning correctly when the thermostat goes.

Post by **JRL** » 27 Dec 2010, 10:20

As was said you need a new thermostat ASAP

However, as was also said, it is NOT good to continue to drive it.
The engine is not warming up, the oil is cold, the water is cold, you will suffer horrible gas mileage and it's NOT good for the engine to run it cold

gditsch · Post by **gditsch** » 28 Dec 2010, 06:36

Thanks guys.. we did drive home after talking to a couple people. It was also 30degrees not 4degrees with high wind chill, so the temp didn't bottom out the entire drive like it did the night before. I will look at getting the thermastat checked. One thing I was suggested to do was place some cardboard in front of the radiator to stop the cold air from hitting it as much... apparently it is something we used to do when I was little and lived in frozen climates. I actually remember this on our old Grand Marq?

Post by **jblackburn** » 28 Dec 2010, 07:06

Don't do that - if you are idling or sitting in traffic, the cooling capacity, even with the radiator fan running, will be greatly reduced if there's cardboard in front of it. If it were Canada or some place where it goes way below zero, that would be acceptable to do.

You just need a new thermostat and it will work as it should again. Once you get the thermostat housing Torx bolts out, replacing the part itself is an extremely easy job.

Post by **JRL** » 28 Dec 2010, 08:40

You don't "check" a thermostat, just install a new one.
They go, it's a common problem on Volvos and actually on many other cars too.

Klausc · Post by **Klausc** » 28 Dec 2010, 13:49

gditsch wrote:Thanks guys.. we did drive home after talking to a couple people. It was also 30degrees not 4degrees with high wind chill, so the temp didn't bottom out the entire drive like it did the night before. I will look at getting the thermastat checked. One thing I was suggested to do was place some cardboard in front of the radiator to stop the cold air from hitting it as much... apparently it is something we used to do when I was little and lived in frozen climates. I actually remember this on our old Grand Marq?

Never block your radiator, your auto tranny fluid is also cooled there. Just replace the thermostat with an OEM. Some of the aftermarket products fail in the closed position, and if that happens you will cook the engine rapidly.

I saw an older Ford van going down the interstate with 5 very cold people in it, the windows were all fogged up and everyone was bundled up. They put cardboard in front of the radiator at a rest stop. I saw them on the side of the road about 15 minutes later, hood up, and old faithful gushing away.