Thermostat

turbotim2 · Post by **turbotim2** » 07 Jan 2009, 07:48

I recently replaced my thermostat for no other reason then the old one was replaced about 60k miles ago and I was there anyway. Against my better judgement, I ordered a Wahler with some other parts. Now the temp gauge continually rises and falls as I drive. It rises to where it is supposed to at just above 3 o'clock and then falls to 4 o'clock before rebounding. The whole cycle takes maybe 30 seconds once the car is warm. When it drops down, I can feel less heat coming out of the heater.
When I bought the car, the thermostat had just been replaced and had failed completely within a couple of months, it too was a Wahler which I replaced with a Stant.
Long story short, don't buy the Wahler thermostats if you have a choice in the matter.

Japedo · Post by **Japedo** » 07 Jan 2009, 08:20

I was going to suggest that it could be a bad temp sensor. But if u are sure u felt the heater blowing hotter and colder in relation to the temp guage it would have to be the thermostat. Ive had to replace 2 temp sensors on my 850 but never a thermostat. Replaced the thermostat on the XC however.

japedo
94 850 turbo
01 V70 XC

bobsnow100 · Post by **bobsnow100** » 07 Jan 2009, 08:42

Did you read the instructions with the thermostat or did you just put it in? I know that when I replaced mine, there was a specific direction where you had to install and align up a reference point on the thermostat towards the direction of the radiator. That is probably the problem.

turbotim2 · Post by **turbotim2** » 07 Jan 2009, 08:53

It is installed correctly.

Post by **confused_al** » 07 Jan 2009, 10:58

turbotim2 wrote:... don't buy the Wahler thermostats if you have a choice in the matter.

+1

Post by **MadeInJapan** » 07 Jan 2009, 20:13

Okay, so 2 people are saying Whaler's are bad....confused-al, did the replacement of that bad thermostat w/ a different brand restore things? I'm just wondering because I've used Whaler and never had a problem. It is important to direct the vent valve forward, towards the radiator (like someone else already mentioned).

Post by **confused_al** » 07 Jan 2009, 21:37

MadeInJapan wrote:Okay, so 2 people are saying Whaler's are bad....confused-al, did the replacement of that bad thermostat w/ a different brand restore things? I'm just wondering because I've used Whaler and never had a problem. It is important to direct the vent valve forward, towards the radiator (like someone else already mentioned).

I had one Whaler worked about 6 months then just out of blue it failed. I replaced w/ OEM one about two months ago, and no issues since then. That time I was told by dealer that the OEM one is not by Whaler but refused to tell who the maker is (one of the Ford thing?):roll:.

Btw, I 'm 90% sure (due to my old age, I'm not 100% sure anything anymore) I installed correctly.

deaster2 · Post by **deaster2** » 08 Jan 2009, 05:23

confused_al wrote:
MadeInJapan wrote:Okay, so 2 people are saying Whaler's are bad....confused-al, did the replacement of that bad thermostat w/ a different brand restore things? I'm just wondering because I've used Whaler and never had a problem. It is important to direct the vent valve forward, towards the radiator (like someone else already mentioned).
I had one Whaler worked about 6 months then just out of blue it failed. I replaced w/ OEM one about two months ago, and no issues since then. That time I was told by dealer that the OEM one is not by Whaler but refused to tell who the maker is (one of the Ford thing?):roll:.

Btw, I 'm 90% sure (due to my old age, I'm not 100% sure anything anymore) I installed correctly.

I installed the NAPA Premium 195 degree thermostat in my 1994 850 non-turbo about 3 years ago with no problems so far. I was having the temp gauge go up and down, as described in a post in this thread. The premium thermostat is supposedly, a "fail safe" type that won't stick closed. This alone is worth the extra dollars for nothing other than piece of mind. I have listed the NAPA thermostat info for the 1994 850 non-turbo cars:

Thermostat Housing Seal
Product Line: NAPA THERMOSTATS
Per Car Qty.: 1
Part No: THM 1070
List 2.47

Thermostat - Regular
Product Line: NAPA THERMOSTATS
Comments: Alternate Temperature;180 Degrees
Per Car Qty.: 1
Part No: THM 138
List 12.32

Thermostat - Regular
Product Line: NAPA THERMOSTATS
Comments: OEM Specified Temperature;195 Degrees
Per Car Qty.: 1
Part No: THM 238
List 12.32

Thermostat - Regular
Product Line: NAPA THERMOSTATS
Comments: Alternate Temperature;160 Degrees
Per Car Qty.: 1
Part No: THM 38
List 13.02

Thermostat - Premium
Product Line: NAPA THERMOSTATS
Comments: Alternate Temperature;180 Degrees
Per Car Qty.: 1
Part No: THM 537080
List 19.17

Thermostat - Premium
Product Line: NAPA THERMOSTATS
Comments: OEM Specified Temperature;195 Degrees
Per Car Qty.: 1
Part No: THM 537095
List 19.17

Sailing_Faith · Post by **Sailing_Faith** » 09 Jan 2009, 16:48

Amazing,

I was getting a P0116 code so I bought a new sensor. I really did not think it was bad, as the dash read out was pretty linear from start up.... but since I read they go bad I figured it was time.

I removed the sensor, and it looked ok, it was stamped 'Volvo' but the car had been dealer maintained up to 99k so it may have been changed before.

I opened the thermostat housing, and was amazed to find the German "Waller" thermostat (also stamped volvo BTW) had actually BROKEN. The braces that secure the springs to the gasket plate are the failure point. One side seems to have cracked loose at the base, and the other side is bent. The thermostat would neither fully open or fully close in this condition.

Add another vote for avoiding Waller thermostats. (although this may well be the original one from the factory for all I know).

Post by **MadeInJapan** » 09 Jan 2009, 18:00

A friend of mine locally had a broken thermostat in his 850 non-turbo when he took it out recently. Pieces were just starting to come loose- very close to going into his engine. Glad I talked him into changing it before the weather got any colder (he wasn't getting any heat!). I'll ask him if his was also a Whaler.