When driving on the parkway my heat blows nice hot air. When I drive around town the air begins to blow cold. Car is running smooth no other issues to report. What could be the problem? 1995 Olds 98 Regency

have you checked the engine coolant level?

Yeah, I originally was down a bit so I thought that I had found the problem but after filling, the problem remains.

Maybe a simple coolant flush?

Your solution doesn't fit the symptoms. Acidic coolant will not cause a temperature fluctuation.

The question is: What cooling system properties change (that should not), and/or do not (when they should), when conditions go from "stop and go" to "highway cruise" and back.

Not much chance the engine temp would vary that much, but the dash gauge is the easiest/best place to start.

Norm

What about the water pump? It spins faster at higher rpms, so it could be pushing the coolant better? Just a brain fart.

A faulty water pump would cause the engine to overheat. Nothing to do with the above symptoms.


Yes it does. Same phenomenon occurs in all (91buickmans, is a possible exception) our cars. Why is it, that all those cars do not show the same symptoms?


How would more coolant flow, make the engine run warmer?


The term applies to the mental equivalent of a "typo" and, as such, it can only be used as an acknowledgment by one who actually knows the subject.

It cannot be used by someone who is asking questions, in an effort to learn more about the topic.

Norm