Running hot, cooling prob

[notimprezed]

OK, so from a post 2 months ago, I drove cross country, broke down in the desert and had the water pump and themostat replaced. Recently the car has been running hot at idle and low speed/engine load. I noticed when at idle for 5-10 minutes at a drive threw (slow a$$ wendys) the temp guage went way up to about the 3/4 mark. It was a cool evening. The fans were running but didnt seem effective. Once under way and on the road though the car cooled back to normal range between 1/4-1/2. I tried to simulate that situation by letting the car idle again at home, the temp went up but not as far but just over 1/2. Then several days later during a bad early season snow storm I was driving home and the temp started climbing again. I couldnt go much faster than 35mph due to conditions. When going under 30 mph the temp seemed to want to head up to the 3/4 mark at which point I would speed up to 35mph and the temp seemed to drop back to 1/2. Then I got behind someone traveling at 20 mph and from this point on the temp stayed at 3/4 occationally hitting the bottom of the red zone before dropping to 3/4 and then going back up again. It also seems that when I let it idle and heat up over 1/2, if I hold the gas down a little letting the rpm rise up around 2000 the temp will decline. Could the pump be bad again not pumping properly under idle and light engine load?

[remark123]

This is a stupid question, but have you checked to see if the coolant is low? you may have an air pocket in the system. I had a similar problem, turned out to be air in the system. I didn't muck with the bleed screw, my car has 250K miles, and I'm sure that if I tried to loosen the bleed screw, it would have broken, its brass, and galvanic action would mean that it is probably corroded in place. I kept monitoring the level in the overflow, adding it as necessary. Took a few weeks, but it is stable now. Temp never goes higher than a tick over the 1/2 way mark now...

[LittleHoov]

His bleed "screw" will be at the top of the radiator on the passenger side, and is plastic not brass.

You might try loosening the bleeder screw and see if you get any air, as it does sound an awful lot like air in the system.


The cold temperature overheating also sounds like the thermostat problem some of the 3.5's have. You just had yours replaced, but you cant necessarily rule out the fact they might have replaced your thermostat with the old style one.

Your symptoms also sound a little bit like a weak water pump, but you also just had that replaced. Might check the belt tension.

[Tobey]

BTW, you only need to turn the bleed screw until air or coolant (if it's full) starts coming out of the little spout on the side. Some people end up taking the screw half way out, which isn't necessary...