23 replies to this topic

[code33]

Do a pressure test on the cooling system to ensure it is holding enough pressure. Check the coolant res. cap.

If it's been awhile, change the T-stat and the sensor near it. Replace the coolant.

Check the freon level.

[kenk]

I would worry more about the engine than the AC if your driving around near the red zone.

If your coolant levels are OK,
replace the thermostat,
check for the fan operation (does it come on?) - does the car tend to overheat when in traffic or regular driving.?

if it overheats in traffic its likely a fan related issue, - check relays, and fuses
if it overheats during normal driving, replace the thermostat - flush coolant
if that still does not fix it, your radiator may have become restricted and may not be flowing at full capacity, so on the hottest of days under the highest of load it lags behind.... you can have a shop test the flow through it.

[WhiteT5]

Replacing t-stat is definitely the first step. Buy new bolts first . Thank me later .

[KLS]

Which thermostat?

--The coolant thermostat?...It has the job of holding the engine coolant at a near-constant temperature. The turbo engine needs the 87°C 'stat, and the normally-aspirated engine needs the 90°C 'stat. The bolts require a long-shank T40 torx bit. The bolt heads usually won't be damaged with the long-shank bit.

--The thermostatic switch that starts and stops the cooling fans?

--Also be sure the cooling system is internally clean and filled with 40% antifreeze & 60% distilled water solution. 50/50 is good if you get into cold winter areas. Antifreeze carries away about half the heat that water carries, so the less antifreeze the better. If you never get into freezing weather, pure water plus a corrosion inhibitor like Red Line Water Wetter works best. If needed, you can clean the cooling system with a heavy duty cooling system cleanser, a powdered product with a powdered neutralizer.

--Be sure the radiator is clean externally. Be sure the air passage is clear of any obstructions, dirt, bugs, etc.

--If all this fails to get the engine cool, your radiator might be plugged with precipitate caused by minerals in tap water combined with chemicals in the antifreeze. Check with a radiator shop...maybe they can clean this out, and maybe a new radiator is needed.


Ken

[ajs850T]

-sounds like a coolling fan issue to me

-like said, just change the thermostat just to rule it out, it's like 7 dollars and 5 minutes to do

[the underlørd]

Quick question: Do I go to like an o'reilly's and get a generic thermostat, or is it something I need to go to the volvo dealership for?

Prestone 337-195

[ziddey]

just in general i've found that most autoparts store generic tstats are absolutely horrid. the oe one isn't too too expensive.

[WhiteT5]

ok, so this prestone 337-195 does not seem to exist anywhere (Can't even find it on the prestone site, except as some sort of tester which is not a thermostat) Every auto store I've tried today has wanted my year, make and model and tried to sell me something I did not ask for.

What are the specs of a thermostat that I need? What temp is best so I can just get one that opens at the right time and get this problem (hopefully) fixed asap?

87 degree one is the one you want, but the dealer only sells the 90° now. Hit up FCP Groton or EEuroParts for the 87° one.

[troyhyde]

Hey partner, you probably need a Cooling Fan Relay. Costs like $60 or so from FCP. Mine failed a while back, same symptoms. I sort of doubt it's the thermostat, but it wouldn't hurt anything to replace it and it is inexpensive. Put the bleeder valve forward when re-installing.

You can see if the relay is shot by turning on the A/C (the cooling fan should turn on immediately and stay on). If the car is hot or overheating, when you turn the engine off the relay will make the fan run enough to bring the engine down to a reasonable temperature. If not, suspect the relay again.

This is a typical "failure" item at the age of your car.

Be careful not to overheat the engine, it will warp the head and blow the head gasket. You'll be in for a fair amount of grief (and more than $60) before you are back on the road.

[Kashif]

When you replace the coolant, stick with Volvo Coolant. I know it more expensive but OEM parts are actually really good on our Volvo's. Well maybe not the sway bars, struts and shocks.

[Kashif]

No 50/50 is good enough.

[ziddey]

Finally got around to flushing the radiator and installing the thermostat (a surprisingly easy task) and everything seems to check out. Idlesd the car for a good 15 minutes with A/C on full blast, and temp stayed right at 3 o'clock (and the A/C is now ice cold). Took her out for a spin on the highway doing some full boost runs and one thing is now different. Instead of going to 13.5psi and creeping up to 15, it shoots straight past 15 and spikes to 17 or so on a shift. Sweet

The only thing that worries me is that a couple of times an orange dash light came on for a split second. Looking in the manual, it's either the service or check engine light. But that may have been cuased by my need for an oil change really really badly.

That's real good to hear! Yeah, volvo's design of a flat tstat placement instead of sideways like many japanese cars sure is good.

Neither CEL nor Service should ever blink for a split second so I'd suspect something else. You said it's an orange light though which is weird. Any chance of it being the coolant light?