If you haven't done it yet, I would reccomend you replace your heater control valve.. This thing costs $20.00 bucks, made of plastic and is simple to replace. On the firewall on the left hand side.

Now for the Volvo testimony:

I've had my 960 wagon for about five years and its issues are the only little ones I haven't felt like fixing. It's a good car. I'm pretty sure the heater control valve on me car was the stock one. Recently, My wife was driving it home one night from one of the suburbs and that little plastic valve just desinigrated and blew both ends off (where the heater hoses attach). Needless to say all the coolant got pumped out of the car instantly. Apparently the gauge never showed getting hot and she drove until the engine SHUT DOWN in the worst possible place. Very dangerous! (She's not stupid so,NO HATING ON MY WIFE!!) Anyway, I got there and could tell it was real hot but did'nt smell coolant. Not knowing what had happened I figured it kicked a rod or something. After a few minutes of dodging 18 wheelers, I got it to start (running like crap) So, I decided to drive it off the interstate with OIL light coming on at every redlight. So figuring the engine was already trash and went ahead and drove it home. The temp gauge still reading in the middle of the gauge the whole time. I got home instantly found the problem and put a peice of copper tube in place of the valve. Waited two hours (no kidding) of patiently nursing it until it would keep water down (not shocking it) so I could completely refill it. All the same time planning where I was going to buy another car.

Believe it or not thats been a couple of months ago and It's still going!!! It's running like it always has. Unbelievable.

Anyway I probably could have saved a big headache, possiblily an engine, and possibly my wife's good health if i'd been smart enough to replace that stupid little $20 valve.

Anyway just a little free advice. Take it or leave it. I know this was a long one. Thanks for reading it..

 

Good point on the valve. The "Low Coolant" warning dash-light should have been illuminated too. It also sounds like Coolant Temp Sensor did its job.

 

Thanks Henry , but as far as I know my car does not have a Low coolant light. I've been completetly through more than one cluster dealing with the famed speed sensor/ trans issue. I wished it did.

 

"Low Coolant" light is in # 15 position (see Owner's Manual here).

 

Your right, I noticed it bulb test this morning. I'll rephrase that statement.


I wished it would have worked.


I promise it did not come on that night. That would have been nice.

 

The heater control valve on my wife's '96 960 has been leaking for a while now. About every 10 days the low coolant light kicks on & I'll add some more coolant. I finally ordered a new one tonight. Over time the leak had dripped unto one of the trans connectors which caused me to have issues which I had in a thread a few months ago.

 

red7218 said, "Cut off the hand that designed the transmission dipstick!"
I wasn't happy with that either, I ended up taking some tig welding rod, bending it & JB Welding it to the dipstick, works great now. Also I have a little funnel with some 3/8 hose & a metal nipple on the tip to add ATF the one time I've had to. It stays looped around the air filter box under the hood.

 

If you think the 960 transmission dipstick is tough to reach, try the one on the XC90 T-6. It's not even mentioned in the owners manual. It's almost like they don't want non-certified tech to check it.

 

I finally replaced the heater control valve on the Volvo today, it broke apart by barely trying to pull the hoses off it. I'm glad nothing bad happened while the Mrs's was driving it.

 

I guess that's the 850's version of the heater core. I haven't seen one of those since my 262.