Temperature gage... stuck thermostat?

l8_apex_it · Post by **l8_apex_it** » 24 Sep 2010, 21:54

With my 2000 V70 GLT I've noticed for a while that if it is cold and I'm driving down hills in the mountain that the temperature gage will dip down very low on the gage (probably the 2nd line or so). Under normal usage it is toward the middle. Even then the temperature gage varies another 2 or three lines. Is this normal? With the temperature level dropping so much it makes me believe that the thermostat may be stuck open. I'm used to my other cars where the needle really doesn't budge under similar usage. Also, the car has about 100k miles and I don't think the thermostat has ever been replace.

Thanks for your input!

Post by **jblackburn** » 24 Sep 2010, 22:39

You're correct - your thermostat is indeed stuck open.

IF you can get the bolts out on the housing, replacing it is fairly simple. Soak them with lots of PB Blaster and bear down hard on the Torx sockets so you don't strip the bolts.

I'd recommend picking up the new steel bolts from your dealer before putting em back in.

l8_apex_it · Post by **l8_apex_it** » 26 Sep 2010, 17:53

Thanks for the confirmation. In general driving in the moderate bay area the needle is pretty steady. Once you get in the mountains especially in cooler weather the needle jumps a bit more. The funny / not so funny thing is that it has been this way for the last few years. I will have to get on this soon.

Post by **jblackburn** » 26 Sep 2010, 20:27

I think you'll be amazed at how fast the heat comes up in the winter again

You might want to put in a new coolant temp sensor at the same time - most of the time when the thermostat goes, it takes that out with it. Apparently not in your case, but it will save you from having to open the housing up again when it fails later.