Running warm
 

In hot traffic my temps get up to 100C and sometimes 105, never any higher. The aux is on but it doesn't cool it down any, it still continues to heat up. It has a 79C t-stat so it is fully open by 82C or so. If I turn the car off at 100C, heat soak will make the temps rise close to 120. Is this normal or is something not right. Thanks

that is usual for the temps to get like that in traffic. Mine was up to 90C in traffic today, plus it was frign hot out as usual.

I wish I could get mine to 90C in traffic. Years ago the temp would stay at 82C and never move, even in the hot summer.

did you check the coolant level? You might also need to test the t stat as well.

Coolant level is fine. Although I do have to top it off due to it running warm and it evaporates.

I might just replace the t-stat, cheap and easy to do. The current one is 2 years old.

Clutch fan not engaging? Often overlooked. Is it original?

I'd suggest topping it off indicates a problem.

There is a recovery tank hidden behind the RF wheel. Any coolant pushed out via the rad cap should return when system cools.

Check your rad cap for spring pressure and rubber seal.

Aux should cut in around 105. As mentioned, your primary belt driven fan clutch may not be engaging. See archives for test.

Jim

The fan does come on at 100C. I don't have a coolant tank on the top of the wheel well, I just have a cap on the rad. I just replaced the rad cap with a new one last week.

The fan clutch is engaged, it has resistance when hot and when cold. It stops spinning as soon as the motor stops running, it doesn't continue to spin.

Oops, my bad, was thinking of a W124.

The McParts stores do sell aftermarket coolant recovery tanks, and you could still fit one on your car.

Did you verify that the cap had a good seal and was holding the spec pressure? Lots of McPart stores have a tester for the cap.



How does the temp gage look when running down the freeway?

If temp rises when rolling at higher speeds, it's the radiator.
Low/no speed overheating is either circulation or airflow.

If high speed cooling is not an issue, and your fan clutch checks out, and you verified the aux is blowing when turned on, then that leaves circulation.

Circulation issues can be the T-stat, water pump, or clogged water passages.

Jim

Going down the road the temp is about 85-90. Stopped at a light its at 100 or 105.

The cap is brand new and has a good seal.

The temps go up at idle and come back down once I start moving again.

I'm suspicious of the water pump, then.

Jim

It could be, the water pump was replaced in 1984 when the headgasket blew.

What makes you think it is bad? How do steel fins go bad on the pump?

Some aftermarket pumps have excessive clearance between the impeller and the housing.

If your sure it's NOT the fans or radiator, you are left with circulation issues or heat transfer problems.

Jim

Just noticed, that waterpump is 24 years old.

Maybe the impeller is slipping on the shaft...

Jim

Is it okay to do a citric acid flush?