Just my opinion but these YouTube video's are general in nature and not Volvo 850 specific. If possible use the correct type of coolant, be careful of the T-30 bolts that hold the thermostat housing on and flush 2 times with distilled water prior to filling the system with the final coolant.

Part 1:
Part 2:

 

Thanks for sharing these videos!

Can I replace my thermostat WITHOUT draining either the radiator or the engine block? I thought I might be able to pinch off that hose going to the thermostat and then replace the thermostat. Is this feasible?

Do you think this thermostat is good? There are 180*F and 192*F versions, and you can get either in either "Failsafe" or "Duralast" I like this one because I don't have to order it online; I can just go buy it at the store.
http://www.autozone.com/autozone/par...6_0_1633_93207
Is it worth the extra 5 bucks to get the fail safe version? Also, should I get the 180*F or 192*F one?

 

^^^Bump^^^

 

I have owned my 93' 850 for well over three years now and it is a great car. Recently since the weather has gotten a lot warmer out I've noticed my temperature go up almost into the red. I quickly pull over my car into a parking lot and let it cool for a while. Then I will drive it back home and then I will turn on the heat at full blast and it will cool off the engine and the car will be fine. Other times it will climb back up into the red and other times it stays where it should be. But what I notice is when I get home and look under the hood the coolant levels are fine. So does anyone have any suggestions of what I should and how to not let this problem happen again?
Thanks very much!

 

Replace the thermostat and if it tries to raise above the normal level again, pull over immediately and get the temp down. The 2nd option would be the water pump has failed.

When the car warms up, try to hold the hose that connects to the top of the radiator. If it's cool, meaning you can hold it with your had for longer than 3 seconds, you likely have bad pump or thermostat.

 

Always get the fail safe thermostat. I also suggest that you only use Volvo or Whaler thermostats. They have a weep hole in them which should be positioned towards the front of the car.

You will not be able to pinch off the upper hose. It may damage the hose.

 

You'll do more damage trying to pinch the hose than you'll save in antifreeze.

You aren't going to loose that much and if all you're doing is the thermostat I wouldn't bother to drain anything. It will spill some when you take it apart and once buttoned up just top it off and next time or two you drive it check it once it's cooled down to make sure it's in the correct range.


#1Yankeefan ;; I'd do the thermostat pronto and if it climbs again I'd check to see if you might have a bad headgasket.

 

I got the 192*F Duralast thermostat, which has a weep hole, and it's worked great so far.

I thought about the failsafe ones, and they seem pointless. The idea is that if the car overheats, the thermostat permanently stays open. But, a non-failsafe would be wide open at overheating too, and well before then. The failsafe does NOT protect against a failing thermostat, only against an overheating car, which would be caused by an outside issue. So far as I can see, they just make you buy a new thermostat if your car gets too hot.

As it turns out, pinching the radiator hose worked great for me! Absolutely no damage was done, and I lost very little coolant, which all got caught in a pan I put underneath the car. After I installed my thermostat, I just topped off my coolant bottle with a few cups of new, fresh coolant.

 

Thanks for the tips, do you know how much it would cost to replace the water pump if it has failed? I will try your tips out and see what happens. Thanks again for the quick reply

 

If you can do it yourself, the pump is less than $100. Otherwise, you're looking at around $300 added for labor. Of course, if it's been a while since the timing belt was done, then you probably want to add those parts also, since the belt has to come off...

 

Glad your thermostat is working for you. A thermostat is a easy part and most will work just fine. I just don't get in the habit of using after market parts in general. On Volvos, it will bite you in the rear sooner or later.

As for pintching the hose, older weak hoses can look fine on the outside and be fractured on the inside. People do it all the time but it may be the cause of hose failure 6, 12, 24 months down the road. To each his own but if you lost 2 cups of coolant, pintching the hose off saved you no coolant loss. That's about the same amount I usually loose.

 

What he said. The hoses are reinforced and when you squeeze them flat you damage the reinforcing cords, how much ?????