Re: Cooling system bubble?
 

Looks like a bubble is not your problem, having used Haibecks bleed method and getting full heat from the HVAC would pretty much count that out. As a final check, make sure the fans are coming on as they should. As you have probably seen running "hot" is both a common problem and to some degree normal. For emissions resasons these cars were set up to run on the hot side of what we are normally use to seeing. I had the same issue when I first bought mine. It would climb almost to max in hot weather around town. I found the radiator fins clogged with fine dirt and sand. Replaced the radiator with a new stock unit, a 180 degree thermostat and a Haibeck chip that turned the fans on at a lower temp. It now runs cool, half or under on the guage, under most conditions. BTW unless your racing or have a highly modified engine, an aftermarket high capacity radiator is a waste of money. IMO
H
:cheers:

Re: Cooling system bubble?
 

Oh god, the sand in the fins! That drove me crazy trying to pick it all out of my rad. Never really got it all either and I'm sure it is affecting my system performance.

I put the "screen" on my car when I took delivery. Then about two yrs later I pulled the rad to clean up the cooling stack. I didn't find alot of leafs or candy wrappers, I believe the screen stopped that stuff. I did have a lot of sand/dirt stuck in the fins. I never got it all as I was going cross-eyed so I gave up after 4 hrs. I got most of it, but not all of it. In hind sight, I should have just bought a new rad from GM.:redface:

My point is that my Z was a G/Queen. Only had 7400 miles when I bought it from the O.O. I put the screen on and that for sure stopped the garbage from collecting up there. I'm not so sure it stopped all of the sand/dirt from getting up in there. I hate to tell you to take apart the stack, but if everything else is okay then Hans is proly correct in his diagnostics.

:cheers:
Tom

Re: Cooling system bubble?
 

Success -- took out the old radiator, swapped in the new one tonight, new 180 degree thermostat, and we're running cool!

The climate control panel reads 87-89 degrees C when at operating temperature. Sounds about right.

Still have a little waver at idle from about 900-1100 rpm back and forth. Runs great otherwise!!

Thanks for the advice, everyone!

Re: Cooling system bubble?
 

Way to go Andy!

You may still want to go the chip route for all the other goodies and the + of the fans on early as well. Perf chip might help with idle too!

Re: Cooling system bubble?
 

:thumbsup: Glad you got to the bottom of this! Whose rad did you go with, if you don't mind me asking?

:cheers:
Tom

Re: Cooling system bubble?
 

Used the stocker from the partsladi. Seems to work just fine!

Re: Cooling system bubble?
 

Thanks for the info!:thumbsup:

:cheers:
Tom