I've had a 1993 850 GLT (naturally aspirated) for about 4 months now. When I first got it the temp guage would run just about in the middle after it got warmed up. For a while now though it's been colder than normal where I am (20's to 40's Fahrenheit) and the temp guage has been staying a bit lower. It stays at the bottom for longer than it used to and when it warms up it tends to sit only about 1/4 of the way up the gauge instead of 1/2.

Is this normal for these cars or does it sound like I need to replace the thermostat?

 

Hello rationull,

Greetings from Chicagoland.

If you're getting cabin heat, you can probably ignore it for now. The problem may be the thermostat getting tired, or the gauge/sender unit. However, you need to know if the engine is about to overheat, so it may not be a bad idea to check the gauge/sender unit. But it sounds more like thermostat. Colder engine uses more fuel, so when youhave a chance it is a good idea to get it replaced. Make sure to use OEM parts, I personally have been usingFCP Grotonof Connecticut.

Good luck,


JPN

 

JPN,

I am getting cabin heat, but it's not as good as it probably should be and it takes a while before the air blowing in really starts to get warm at all. I take it that further point to a bad thermostat? I'll probably just replace the t-stat then and if it still looks bad I'll test the sender.

Thanks!

 

Hi rationull,

Yes, it does sound like a thermostat that is getting stuck-open, allowing over-cooling and delayed warm-up. With the car's age, it's not surprising. It'll allow engine to run rich and dilute oil faster, so the sooner the better to replace it.

When you replace it, make sure to go with OEM t-stat (I used French Vernet, but German OEM is available as well, if you can find a 87-degree Celsius version, I would go with it). If you can do it yourself, you can save some $ andthe procedure is easy but you need Torx,as the t-stat housing is held by two Torx screws. If the coolant (antifreeze) is more than 3 years old, it's not a bad idea to replace it with 50/50 (55/45 in extremely cold place like Canada) mixture. The new t-stat should come with new O-ring, and there is no gasket required. I personally like to use a tube of Loc-Tite brand thermostat/water pump sealant between the mating surfaces, though not absolutely necessary.

If you need to have a shop do it for you, ask them to see if they accept parts from customers. Also, when using a shop for servicing Volvo, I strongly recommend either the dealer/shops that specialize in Swedish/European cars (the latter may be better/cheaper if you can find one). The cost may be as high as 20-30% more than generic garages but it's well worth it (I wrote this phrase many times to other people).

Good luck,


JPN

 

Thanks. I just went over to the Volvo dealer and picked up a thermostat from them. I'll just do the job myself. The advice about using the dealer or european specialist shops in general seems to be pretty common for getting Volvos serviced and I'll definitely take it somewhere like that if I ever do need to bring it in for anything.

One more quick question if you happen to see this again, since I don't have access to any manuals or anything right now: how much coolant in general do you have to drain so that it doesn't spill all over the place when removing the thermostat?

 

I changed mine and didn't drain any coolant before starting. It leaked some on the floor, but not that much. I just cleanned it up before the dogs got to it, although my dogs won't have anything to do with it. I have heard of dogs that will drink the stuff and it's poisonous to them.

 

Yeah, I've always heard cats and dogs are drawn to antifreeze for some reason too. Good to know that it doesn't spill much. Thanks for all the help!

 

Hello again,

Good point Jim (I decided to take off "Mr.", as my former instructor wanted me to address him by his first name, and other people seemed the same), Chilton always starts with "Keep in mind that cats & dog areattracted....will be fatal if swallowed". Little toddlers may try to do the same, so watch out.

I would drain a quart or so just to avoid mess, place an empty bottle under the drain **** (driver's side, on the bottom of rad) and loosen the **** (no misunderstandings, gentlemen) with a deep-well socket (again, no misunderstandings, gentlemen), if you have a clear rubberhose of the correct diameter, you can connect it to the **** and guide into the bottle. When tightening the ****, finger-tight plus 1/16 turn will do, if you turn it more, it may break off as it is plastic. You can then recycle the coolant into the expansion tank.

Pay attention to the facing direction of the bleed hole on the stat. The tiny bleed hole has to face down, that is, 6 O'Clock position as you're viewing it from front. By the way, did you get a new O-ring as well?

When removing the two Torx screws, expect them to be very tight, so make sure to have the correct size Torx.

I hope this solves the problem.

Cheers,


JPN

 

Where can I find the T-stat? Where is it located?

I think I should fix this....But my garage is so dirty from the snow.

Edit: And I mean physically on my car where can I find, not where online.

 

Looking at the engine bay from the front of the car the thermostat is right behind the power steering fluid reservior. Two hoses connect to it: a small one going into the coolant overflow tank and the larger upper radiator hose. The dome held down by two torx T40 bolts.

 

http://www.matthewsvolvosite.com/tstat.php
http://www.volvospeed.com/Repair/thermect.php
http://www.volvospeed.com/Repair/thermect2.php

That should get you going.

Remember to be very careful when you remove the Torx screws on the t-stat housing. It´s all soft aluminum.

Oh, and use an original Volvo thermostat. Don´tgo cheapo there since tstat failure will cost you thousands.

Good luck!

 

So i'm looking at thermostats...

FCP Groton has the cheapest one at 15 bucks shipped/ or 9 bucks for the part. It's by Vernat (OEM?). Should I go ahead and buy it?

I ask because partstrain.com has two brands Germany/Wahler both marked as OEM. Their prices are just like all the others at around 14-16 bucks. If I can save like 5 bucks buying the FCP Groton one, imma do that.

Thanks,
-Jimmy

 

Hi Jimmy,

Vernet is a French OEM, and that is what I installed. The one I bought was 87-degree Celsius, but 3-degree difference in Celsius is negligible.

Sometimes there are more than one OEM mfg for certain parts. Don't know why, maybe political reasons?

I once bought parts from Partstrain, but have completely switched over to Groton, no one else seems to come up with parts illustrations like Groton does, and Partstrain and many other (almost all) vendors seem to use the same database format, and it it boring.

Anyway, either one will be fine. When you replace it, make sure to face the little bleeder on the t-stat at correct location (6 O'Clock I believe but check with your manual).

Good luck,


JPN

 

The bleeder goes to the highest point. This way the air bleeds out.

 

Alright, I trust your info, so Imma get the 87 degree one also. :lol:

I've never changed the t-stat before, but it doesn't seem like it's that hard. I'll check those links up top, but will make sure the t-stat bleeder is in the right position...

And unless I'm misreading, you and tech are offering differing info...Should the bleeder go to 12 o'clock or 6 o'clock?

 

Just wanted to say thanks for all the info! Changed it out yesterday. The temperature's looking good and the heater works wonderfully again.

 

Hi Rationull,

Glad your 850 is up & running again. Good start!

Jimmy,
Bay-13 says the bleeder port has to face down (6 O'Clock). But when in doubt, go with M. Tech's advice. I wonder if he meant "highest point" as in height, usually bleeder port is located at the highest point of the cooling system.

Good day to all,


JPN

 

Got the Part in the mail today. Gonna probably install this weekend (Even though the temps as HORRIBLE. Single digits...I think today was the last day of double digits (14 degrees F) LOL)

Still a bit confused as to which way the t-stat should face. The pictures are all showing the 6 o'clock position, but Tech is saying opposite. I just want to get it right and not experince a huge t-stat failure which axel mentioned.

One more question, in the tutorials, both of them have you drain the coolant. Is that necessary or can I just replace the t-stat?

 

Hello Jimmy,

When I installed my t-stat, I actually didn't pay attention to the facing position, until I re-read the instructions on Bay-13. However, my 850 never had t-stat related troubles. I might have had it at the correct facing direction but who knows. Wait till M. Tech replies to you to see if he meant the "highest point" as 12 O'Clock position or something else. Or, check the inside of the t-stat housing and see if there's a tiny hole. Logically, wherever the hole is should be where the bleeder port goes to.

I would definitely drain the coolant (at least partially) before proceeding. If you don't, it'll make a mess. If the coolant is over 3 years old, it may be a goodtime to change it as well. I went to a local ACE hardware and bought a clear hose to attach on the drain ****. This makes the job much neater. Some auto parts stores take used coolant, so you might want to check that out.

One note: Some manuals tell you to fill the expansion tank to "FULL". If the cooling system has been drained completely, it is ok to fill the tank to FULL, as the level drops after the t-stat opens. Also, coolant level usually drops overnight, after being drained & refilled. After that, the tank should be filled between FULL & MIN. I once filled it to FULL when cold, and coolant started to spill out of the cap.

*Keep in mind that dogs & cats & toddlers are attracted by the smell of coolant and are likely to drink...if sufficient quantity is ingested, it is fatal...(quote from many manuals).

PS: It's been freezing in Chicago too. Yesterday I spent about 8 hours outside, working on a company truck ('92 F350). When I was done, I felt numb.


JPN

 

You need to put the bleeder hole at the highest point of the housing when looking at it.
Which I believe that is towards the front of the car.

I never drain the coolant to change we have a BIG pan to sit under the car.