yet another question about running too hot

mike944 · 08-13-2003, 08:14 AM

Hi guys,

My car is running too hot for my liking. it runs between 1/2 and 3/4 on the gauge. I have never had any problems like this until about 3 months ago. It started running hot, and i noticed that my coolant level was low, and my water pump was leaking. I figured the hot running was due to ait that got into the system from the leaking water pump. it never ran over 3/4, I stopped driving it, and replaced the water pump, thermostat, and timing and balance belts. I bled the system like you're supposed to, several times, in fact! Since i have replaced the water pump, the temperature has never returned to normal. Before all of this, the car NEVER ran over 1/2. I've checked the fans and they both operate properly.

I've noticed that, at idle, the air blowing from the fans is warm, but not hot. If i rev up the engine, the air blowing from the fans gets HOT. This tells me that the pump is not circulating enough coolant at low RPM's Once the RPM's come up, all the really hot coolant gets pushed into the radiator, the radiator and fans seem to do their job, of getting the heat out, properly.

Somebody mentioned that it could be a leaking head gasket, which i doubt, since it was changed 15K ago. On my way home today, i am going to stop at an auto parts store and see if i can find one of those things that you put into the radiator cap hole, to see if combustion gasses are present. That should answer the head gasket question.

Any other ideas????? i'm stumped!

Mike

NYC_SpeedRacer · 08-13-2003, 08:19 AM

is ur coolant level still low at times....maybe u have a slow leak somewhere.....where it leaks so slowly that by the time it leaks out its burned up

Lawrence Coppari · 08-13-2003, 10:46 AM

Quote:

I've noticed that, at idle, the air blowing from the fans is warm, but not hot. If i rev up the engine, the air blowing from the fans gets HOT. This tells me that the pump is not circulating enough coolant at low RPM's Once the RPM's come up, all the really hot coolant gets pushed into the radiator, the radiator and fans seem to do their job, of getting the heat out, properly

It could also be telling you that there is restriction in the radiator (or elsewhere) and that more pressure from a faster running pump is needed to get the coolant through.

Also, I would check to see if the pump is slipping on the cam belt. That would not be good.

mike944 · 08-14-2003, 07:23 AM

thanks for the replies.

The coolant level is fine, i've probably only put on 100 miles since the water pump replacement.

The pump shouldn't be slipping on the cam belt, i tensioned the belt properly using the P9201 gauge (yes, i actually bought the $$$$ thing)

The only other thing i can think of would be a clogged radiator. Why would this happen so suddenly?

I picked up the combustion gas leak detector kit yesterday, but haven't had a chance to use it yet. I have my doubts about a leaky head gasket, because the coolant hasn't "boiled" over, like would be typical with coolant system overpressurization because of high-pressure combustion gasses leaking into the cooling system.

Does anyone know what actual temperatures correspond to gauge markings? I can put a thermocouple in the radiator hose, to see if maybe the gauge went bad.

Mike

944pete · 944pete's Garage

I've got the exact same issue. I just changed a leaky waterpump also. I think there may still be an air pocket in the system somewhere. I'm going to bleed the system again. The lack of hot air from the heater points to air in the system. These cars are very touchy about that.

highboost951 · 08-15-2003, 09:41 AM

just in case, take the cover off and see if you can turn the waterpump by hand, if so, retension it,

TCMdocs944 · 08-15-2003, 05:35 PM

TCMdocs944 · 08-15-2003, 05:36 PM

Ooopps, I think this pic is in centegrade...No the us farenheit

ronin · 08-15-2003, 08:38 PM

definitely centigrade

highboost951 · 08-16-2003, 08:01 AM

that's the outside temperature gauge