95 Grand Am GT 3.1 Cooling Sys Problem

Hello.. I hope someone can help me out.. I've been having a hard time with my 1995 Grand Am GT 3.1L cooling system.

Here's whats happening..

The temp will rise above 230 at an idle/low rpms, and I'll get no heat from the car. But, as soon as I accelerate to above 2500rpms, the temp drops down to normal and I get excellent heat.

Here's what I've already done..

I've replaced the intake gaskets, new radiator, both temp sensors (pcm and gauge sensors), coolant flush, properly bled the cooling system. I've also put a vaccum kit on the cooling system and backfed the coolant to refill. The system holds perfect pressure with my stant pressure tester, and also holds perfect vaccum at 15lbs. I've also check the engine several different ways for a possible head gasket leak.. all turn out negitive.. what the heck am I overlooking?

Any help or suggestions would be greatly appriciated!!

--John

Reply to
John
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Sure sounds like air in the system. When a slug of hot water hits the heater, you get heat.

Reply to
=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?=

Waterpump??

Reply to
Mike

"=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?=" wrote in news: snipped-for-privacy@pyats.rr.co.tx:

I agree.. but I sure can't find out where.. system holds perfect on both pressure and vaccum.. I'm lost.. =( .. I've heard where the veins rot on the waterpumps.. and thats where I'm leading.. but damn, I've spent a lot of money on this car already ;)

Thanks for the reply!!!!

--John

Reply to
John

"Mike" wrote in news:Kytec.41461$ snipped-for-privacy@twister.nyroc.rr.com:

Thats what I'm hoping.. thanks for the reply!!

--John

Reply to
John

I've seen worn down vanes on water pumps but don't know if that would have the affect of intermittant hot water to the heater core. If the system were entirely filled with coolant and you put the pressure pump on the system, it ought to max out in only one or two pumps since water does not compress (taking into account hose expansion).

Reply to
=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?=

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