'96 850NA What temp thermostat should I choose?

Post by **dosbricks** » 15 Jan 2015, 19:14

From searching the archives, it appears the original equipment stat is 87 degrees C for turbo and 90 degrees C for NA. But I replaced my radiator last summer with a Behr, and afterward the temp gauge sat about 1mm above the normal 3:00 o'clock position. Others have experienced the same with aftermarket radiators. I would prefer the engine not run above normal temp.

As PM, I plan to replace the heater core in a week or so and I'm wondering if switching to the 87 C Wahler would lower the summer operating temp. I say summer because that season is hotter than a cayenne pepper down here in South TX. Right now with temps in the damp 40s the gauge is showing 3:00 o'clock.

Note: I replaced the radiator cooling fan with an Erie vovo JY unit because the OE was starting to have a noisy bearing--if that has any bearing on my situation--but it didn't change anything regarding the summer engine temp.

Any guidance would be appreciated.

dos

Post by **oragex** » 15 Jan 2015, 20:33

The different needle position may also be caused by a little bit of air trapped where the temp. sensor sits.

The temperature should not go higher than the t-stat rating, no matter the radiator. Unless the stat got stuck open

As for the t-stat, for a n/a just a difference of 3 degrees won't make any difference at all, even with the mixture burning. Perhaps if it was a turbo, the t-stat temperature would be more important.

On my n/a, the original stat was at 91C, the replacement one is at 89.

Does the cooling fan has the controler unit separately? Maybe switch the controler from the oem fan to it.

Post by **cn90** » 16 Jan 2015, 10:22

The 90C Wahler is fine. This is what I use.
Since you are in Texas, you can also use the 87C type.
Eeuroparts has both:
http://www.eeuroparts.com/Cars/Volvo/17 ... systems/1/

The Aux fan, if you remove the motor, you can replace the small bearing.

Post by **misha** » 16 Jan 2015, 11:13

Temperature range from 87-92 degrees Celsius for non-turbo and always make sure that you buy a quality thermostat (Vernet or Wahler) which,in case that it will fail,will always fail in open position.

92 degrees thermostat for na engine is usually used in very cold climate.

Post by **dosbricks** » 16 Jan 2015, 14:48

Thanks guys, I'm going to go with the 87 C Wahler and also put a new temp sensor in there while I'm at it. I'll report back but it might be a while before we get a hot day--like February

Post by **misha** » 16 Jan 2015, 14:57

Don't buy aftermarket ect sensor,go with OEM.

Post by **dosbricks** » 16 Jan 2015, 17:56

misha wrote:Don't buy aftermarket ect sensor,go with OEM.

Yes, I ordered the Volvo ECT--but Ouch! $55 USD.

Post by **misha** » 17 Jan 2015, 00:34

From a stealership or from somewhere else?

Post by **dosbricks** » 17 Jan 2015, 08:32

Post by **misha** » 17 Jan 2015, 09:45

Those things rarely go bad.Mine is still original and no problem with it.

Last time when i replaced coolant & thermostat i removed it and sand it with fine sand paper while was in that area,just in case.

That said...if your is working ok and no codes for it you didn't had to buy new one.