esandes

car: 1990 ES250

the car keeps overheating on me when it is driven hard. for example, the other day i was driving up a long and constant incline and the temperature gauge kept climbing even though i slowed down well below the speed limit. i had to pull over.

it was belching out coolant.

is the exhaust too restrictive? what other causes could there be for overheating issues.

Tammy

A partially clogged radiator is more than likely the cause.

Check the seals on the radiator cap for cracking or rubber deterioration.

esandes

i was told the rad is new. i'll check the cap.

Tammy

An on going problem with a history?

Has the water pump or heater core been replaced, to your knowledge?

An additional consideration would be a failing head gasket or two. A compression leak down test would confirm if this were the case.

This may happen when the coolant is never changed and corrosion has set in.

esandes

the water pump was replaced 2 months ago.

if the head gasket fails/leaks wouldn't there be a loss of power and knocking?

there is no smoke in the exhaust and the coolant doesn't appear to have any oil or bubbling. the only time the coolant bubbles is when it overheats. one time i pulled the overflow hose out of the reservoir and steam was coming out.

i'm thinking the heater core or rad is plugged.

perhaps next time i should use premium fuel on long hauls to help drop down the heat.

esandes

i heard that a complete coolant system flush will clean out any plugging in the colling system. that will keep the engine from overheating.

clubfoot

Make sure that the thermostat was installed correctly.

Pheonix

A flushing won't clear plugs. They just help. For example. You can't fix a cloggedradiator. Well you could... But you would never actually go to the trouble.
Check the radiator fan, thermostat, pressure caps. Flush the fluid & check the coolant temp sensor. From there check that the radiator is not pluged, the water pump has not had it's vanes corroded off & that the head gasket isn't blown.

esandes

well the other week i drove it hard up a hill and it didn't overheat. i used premium fuel and the temperature was a bit cooler than before. maybe the plug got cleared out. i drove it up the same hill it used to overheat before and the temperature gauge kept steady at normal.

esandes

i have also experienced a situation where i'd highway drive and then stop the engine (went to a restaurant). i'd come out after a few minutes and attempt to start the car. nothing. no turn. just solenoid valve noise.

i pop the hood and see that the coolant fluid has expanded from the high heat from the engine. prior to stopping the engine the temperature was normal. after some time the coolant level drops down (engine cools off) and i attempt to start it again...it starts.

i think i will let the engine idle for a while before i shut off the engine after some highway driving. when i shut the engine off, the water pump also stops.

Pheonix

First rule of overheating. Never shut off an engine while it is in the process of overheating. It's bar none the worst thing you can do.