Grand Prix heat bypass

[Eric Wettschreck]

2002 Grand Prix, 3800, 140k Miles.

The other day the dreaded plastic elbow/heat bypass fitting finally broke. Yesterday I took things apart and replaced both plastic elbows with aluminum. Filled with coolant, started, got up to temp, vented, thought everything was good to go.

Wrong.

I know it's July, but I can only get heat if I have it going down the road. If it's sitting in the driveway at idle cold air comes out.

I vented things again. I'm assuming stat is good as temp goes to 210 and stays there. Fans kick on and off as needed. Hoses going to heater core are pretty darn warm. Possible I knocked loose a chunk of pookey and it's now wedged in the heater core? It's the only thing I can think of but it's weird as both hoses are equally warm.

Any thought?

Thanks.

[Jeremy airjer W]

Get yourself a no spill funnel

You can find them at your local NAPA.

Install on a cold vehicle, start and let it come to full operating temp. Snap the throttle several times. You should see a bit more air come out. Top off as necessary.

Sometimes, if the a/c is working, I like to turn on the A/C when the car gets to about the 200 mark. This will keep the fans on and the coolant cool enough that it wont boil over as much while your trying to burp. GM's generally dont turn on the fans until the coolant hits the 220 mark which can lead to a lot of coolant getting pushed out of the radiator.

If this is unsuccessful than it may be possible that the heater core is plugged. Especially if the coolant was really nasty looking. If you think this is a possibility the heater core can be back flushed with a garden hose.

[Eric Wettschreck]

Thanks Jer, I'll give that a shot. It just seems a little weird to me. I thought I had it vented out real good but I've been wrong before.

[Eric Wettschreck]

That was the deal Jer thanks. I burped out a big arsed air bubble and voila, everythings buffy.

[Jeremy airjer W]

Good deal.

Those no spills are fantastic!