1997 960 Thermostat temperature

[GardensInMyMind]

Hi
1997 Volvo 960 wagon
Short version: I am having issues that look to me like I need to try replacing the thermostat (cheap thing to try) and there are temperature options:160, 180, 192 (or 195). Which one would it need? I'm guessing 180, but that's only a guess...

Long version: I washed the car well (was last done 4 years, 4 houses, 3 deaths and another state ago, haven't had time) including clearing a lot of debris out of the windshield drain port things (which were pretty solidly clogged, this car has mostly been parked, had to use a sink drain cleaner wire, lots of debris.) The next day after about 12 miles driving with several stops, it suddenly started blowing steam out of the vents (the A/C was on and functioning.) Pulled it into the shop it was in front of, the guy said heater core. FWIW, the steam did NOT smell like coolant, only water, and when I opened the hood there was also steam coming out of the windshield drain port things I had cleaned the day before.

Took it home, pulled the panels under the dash, added more coolant (was very low), ran it, could see drops in that area (both sides) of fresh coolant. I can't afford a heater core replacement right now, so I disconnected the tubes that end up going through the firewall at the metal sections behind the block, put in a loop to connect them, made sure it cannot kink. Ran it this morning to test it, temperature went up fast (about 2 mile run, was at half.) So thermostat is my next guess. Any better guesses would be welcome And if thermostat is a good guess, which one do I order?

Thank you all!!
Pearl

[GardensInMyMind]

Update: After posting that, went out to check the fluid level (since it has cooled down) it was slightly down (but there were probably air bubbles in the system.) It's possible that loop I put in IS kinked. I had made an arch out of a section of a #10 can, looks like it bent more that I thought it would.
I'm about to redo it....

Advice is still needed...

[GardensInMyMind]

Fixed the possible hose kink, didn't change the problem.
About 2 miles driven, temp gauge at half. It was going up too fast to try running it longer to see how high it would go.

[Inline5fan]

Hey there. I have the same car...and she has some miles on her...and she does warm up quickly on the gauge, but she will stay at that midway point rock steady. But I would say that mine warms up just as quickly. But then
doesn't go passed that mid to two thirds point. I would try letting her warm stationary at idle from a cool engine and see if the temp gauge ever goes past that mid point. Mine will idle for nearly 20 minutes before the fan comes on. So, I am almost thinking yours may be fine. If doing the idle test, be sure you don't have any air in the system. One way to confirm this would be having working heat, but that would not be an option in your case with bypassing the heater core.

HTH. Let me know how you make out.

Ted H.
1997 965 221,000 miles and climbling

[GardensInMyMind]

Interesting. I haven't been driving that car much, and perhaps I have forgotten what her normal operating temperature is, or am just paranoid after the heater core... I'll check it in the morning, heat wave here, I don't think this afternoon is a good time to heat test anything.

I did put in a loop of pipe with no fluid in it, so air is in the system, if it didn't get out when I first tested it. If air might be an issue, how can I bleed the coolant system? Seems like it should just burp into the fill tank. The amount of coolant it went low when I ran her is about how much it would take to fill 2 feet of pipe.

My lady Volvo is at 288,185 miles I bought her high mileage, most of the miles were highway, and if a Volvo hasn't crapped out by 100,000, they'll run forever. I think it was worth it She's a good car, with a few personality quirks, nothing so horrible I can't deal with them.

[GardensInMyMind]

Ok, tested with it idling. Fan kicked on at exactly halfway up the gauge. My loop was good and hot, with no leaks. Haven't checked fluid level yet, too hot to open that lid.

So this means, I think, PLEASE correct me if I'm wrong, that all it needed was the heater core bypassed, and it's otherwise fine. I don't think the fan would have kicked on if the thermostat was bad.

There is a small vacuum leak, don't think it's related, looks like mouse damage. When I hold it in place it doesn't obviously change how it runs. I did have to fix a bunch of vacuum lines due to mice a year or so ago.

Incidentally, I DID have issues with the coolant pressure lid a few years back (viewtopic.php?f=2&t=73506&p=388053#p388053) but did put the correct cap on, as far as I recall. Definitely shows no signs of head gasket problems.

So do I dare run it and see if it blows anything? I'd love another opinion before I do so! Can't afford to damage anything.