low heat in cabin at 32f outside.

iceracer · Post by **iceracer** » 07 Dec 2011, 20:10

Hi There:

I have a 98 v70 non turbo 5 speed.
This morning I was driving to a job site about 40 minutes north of where I live.
The car had been in a heated garage over night. About halfway to the site, the air coming out of the
heater started to cool and the temp gauge for the engine started to drop. Outside air was around 32F.

On the return trip home tonight, the temp at the job site was around 32F.
The engine temp hovered just above the minimum and the air out of the heater was warmish, but
it was cool in the cabin. Had it not been for the seat warmers, I would have to put a jacket on.

As I got closer to home, the outside air temp rose to around 34F. About 5 minutes from home the engine
temp came up to normal range and the heat out of the heater was nice and toasty.

Any ideas as to what may be causing this anomaly?

Thanks, Terry

applcor · Post by **applcor** » 07 Dec 2011, 20:23

Sounds like the Thermostat stuck in the open position for awhile, then about the time you got home it came loose and started functioning properly again. You can bet it will do it again, but it might be a good while. If it does it again the thermostat needs to be replaced. At least that is much better than it sticking in the closed position though!

Post by **burnout8488** » 07 Dec 2011, 20:47

Agreed! Lucky it failed open.

iceracer · Post by **iceracer** » 08 Dec 2011, 04:41

But the car operated fine at first, after having been in the heated garage overnight. Once the outside air was around 32F did things change.

At around 34F it operated normally too.

I've heard, but do not know for certain that it could be some type of sensor that regulates the AC from operating below freezing?

Terry

Post by **jblackburn** » 08 Dec 2011, 06:48

It's the thermostat. The engine temp is rising or falling depending on how much airflow is going through the radiator. High speed = more air = cooler engine.

The thermostat should open and shut accordingly to maintain the coolant around 190-200 degrees.

Go with a Wahler OEM thermostat so you don't get an aftermarket one that can fail shut in the closed position and overheat your engine in a matter of minutes.

iceracer · Post by **iceracer** » 09 Dec 2011, 05:07

I have access to a Calorstat, or a BEHR thermostat. One is an 87 or 92C version.
My car is a non turbo 5 speed manual 2wd.

Terry

Post by **jblackburn** » 09 Dec 2011, 09:16

Calorstat is a good brand, temp doesn't really matter. For what it's worth, though, 92 is standard for non-turbos, 87 for turbos.

iceracer · Post by **iceracer** » 09 Dec 2011, 19:18

Thanks for the info. I contacted a local Volvo dealer today.
By the time I order this one piece online, It'll cost just as much as to get it from the dealer.
31.00 cdn. for an OEM version.

Appreciate all the feedback, I'll post results once done.

Terry

iceracer · Post by **iceracer** » 12 Dec 2011, 05:04

Thanks for the words of advice. It was the t stat.
I've attached a pic and you can see where the bracket broke.

Put in a new OEM unit (wahler) and it's running fine again.

The DOM stamped on the old one was 08 03 so it must have been changed by the previous owners
at some point as well.

The old unit was also a wahler unit. It was a pretty easy project and I changed the antifreeze while at it.

Thanks to my good neighbor Pete, who has an awesome set of just about any tool needed. He had the right size torx bit for the housing bolts..T.

Post by **jblackburn** » 12 Dec 2011, 07:24

I bet it's nice to have heat again! When my thermostat broke (I didn't really notice until it got cold), the heat coming out of the car was almost as pathetic as the heat pump at my apartment.