2001 Malibu Problem

The engine in this car continues to overheat at freeway speeds. We've
replaced the water pump, thermostat, radiator, coolant tank and the pressure
cap. Filled and bled the system, fans work, idles all day long with no
problems. Get up to speed and it overheats. Any ideas? Thanks.

Patrick

"happytaxi" <happytaxi@comcast.net> wrote in message
news:iKGdnd4OW4NojFrcRVn-sQ@comcast.com...
> The engine in this car continues to overheat at freeway speeds. We've
> replaced the water pump, thermostat, radiator, coolant tank and the
pressure
> cap. Filled and bled the system, fans work, idles all day long with no
> problems. Get up to speed and it overheats. Any ideas? Thanks.
>
> Patrick
>
>

Did you put a pressure tester on the cooling system to see if it bleeds off
in pressure? Are you loosing coolant? Cracked head? Did it overheat real bad
prior to all of the problems you have now?

Brian

On Mon, 20 Dec 2004 16:59:26 -0500, "el Diablo" <nomail@spam.not>
wrote:

>
>"happytaxi" <happytaxi@comcast.net> wrote in message
>news:iKGdnd4OW4NojFrcRVn-sQ@comcast.com...
>> The engine in this car continues to overheat at freeway speeds. We've
>> replaced the water pump, thermostat, radiator, coolant tank and the
>pressure
>> cap. Filled and bled the system, fans work, idles all day long with no
>> problems. Get up to speed and it overheats. Any ideas? Thanks.
>>
>> Patrick
>>
>>
>
>Did you put a pressure tester on the cooling system to see if it bleeds off
>in pressure? Are you loosing coolant? Cracked head? Did it overheat real bad
>prior to all of the problems you have now?
>
>Brian
>
check your idler pully tension,
also check that your serpentine belt isn't glazed

might also want to check the performance of your tranny. if it's
heating up.....

also, I know that you'd have ruled this out but if the car has a bra
or some other restriction (big fog lights) that will reduce cooling
efficiency.

Failing that you could have some obstruction in the engine somewhere.
You'd have to reverse flush it and measure the flow to rule that out.

Best of luck & Merry Christmas

> Did you put a pressure tester on the cooling system to see if it
> bleeds off in pressure? Are you loosing coolant? Cracked head? Did it
> overheat real bad prior to all of the problems you have now?
>
> Brian
>
I concur with this. I recently had a similar problem with my 02 Malibu.
One gasket had a leak and caused the cooling system to lose pressure,
causing the car to overheat whil driving.