My temp stays down (like 0) until the engine is nice and warm- 10-15 minutes of driving, and then it comes up to the appropriate range. I'm thinking that the sending unit is going bad and is having increased resistance in the circut that it can't overcome at low temps, but once it has hit a certain voltage then the circut completes and put out the signal.

Anyway- not an electrical engineer- but wanted to know if anyone else had experinced this issue. Car is a 850t 1996, with 140K. I'm thinking of just starting with a new temp sensor, and new thermostat, and thinking that will fix it.

Thanks

 

i would go that route also

 

+1, It is not expensive to swap them out and it could be all you need.

 

Sounds like a plan. FWIW, the Torx screws that hold the thermostat cover on are a real PITA at times. I would replace them with regular hex head's while you are in there

 

+1, also soak them in PBlaster overnight or you will strip out the threads.

 

Extended torx socket will make it easier.

 

Silk hope you are right. Those TORX are beast. Just to follow up the condition-

I replaced thermostat and sensor- so it's a chicken and egg thing...

Now I get to operating temp within the first mile- hard to assess the mileage situation and driving has been sporadic and I've got the bike rack on top. It never set any codes.

Now my temp gets to just a little above 3 o'clock, as I went with what FCP said was Volvo Original for 850t. My old gauge read right at 3 o'clock, and this was is rock steady. It would be too much trouble I think to replace one and not the other.

Before doing this get some 3" TORX, an impact driver, PB blaster and new bolts to replace the TORX. I forget the thread size and pitch, I might have written it down somewhere- I meant to post it for the 850 nation- it's not that standard.

 

Glade all is well for this fix, now wait for your next fix, it will be coming sooner or later.