I have the L03. You can check my sig for mods.

I let my car sit for a few minutes after I start it and I get heat in my car. If I run it on the highway, and it's below ~50 deg., then I get heat for a little while, then I get cold air from the ducts. Then a few miles down the road I get warm air again. Just long enough of a delay that my wife complains.

Does the 180* T-stat have that effect? Is it because it keeps closing to keep the engine warm? Or is the heater valve shot?

I have read on here about the heater valve and that a few of you have deleted it. But I've found no posts that mention the same problem I'm having.

I thought some of you said that the heater core gets antifreeze regardless if the T-stat is open or closed, because of the heater valve. Is that right?

Thanks for any help,
AJ

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92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford Punch 100. 1 - MTX 12" sub

 

I don't know how much help this is but the only times I've had that happen is when the coolant is low or there is air in the cooling system. If you just had any cooling system work done that could be it. Especially the air problem.

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'92 firebird t-tops
305tbi,670cfm tbi, 2 1/2" Dynomax catback, 9x3 K&N open element

 

The coolant resevoir is fine. I guess I can check the level in the radiator. I checked it everyday for a week back in June, when I first changed the temp switch and T-stat. It was fine then.

I'll let ya know,
AJ

 

The level was a tad low in the resevoir, but fine in the radiator. The resevoir was at "Full when cold" line after the engine was warm. I added a little mix to the "Full when hot" line.

I guess I'll have to wait and see. I doubt if that little amount would make that big of a diff, but who knows?

AJ

 

I still think you have air in the cooling system. I had this problem on my daughter's car. I thought I had the system full, and that's how it showed in the tank and on the resevoir. The car still had spotty heat. I finally took the cap off the radiator aand brought the engine up to temp. As I let run every few minutes the radiator would burp a big air bubble. It took about 30 min. till it quit. Now it has constant heat.

 

Yeah - sounds like air in the system to me. I've seen the same problem on a couple other cars. If your stat was opening and closing that much you'd see your temperature guage bouncing up and down a lot, right?

You're right, the heater valve stays open (it is vacuum controlled by the slider on the console) and allows coolant through the heater core as long as you have heat selected on the inside slider.

I'd do what 92blackbird did to purge the air (run w/cap open).

 

Cool.(Edit. No pun intended HEHE.) I did let it run the other night with the cap open so that the T-stat would open. I don't think it ran but maybe 10 min. though.

Air in the system would make sense. I swapped the fan switch without draining the coolant. That spot is perfect for letting air into a "pocket".

Thanks all. I'll try that and let ya'll know.

AJ

[This message has been edited by AJ_92RS (edited November 10, 2001).]

 

OK. I did the "let the car run for a 1/2 hr. with the radiator cap off". I couldn't tell if any air pockets were released or not.

I guess I'll have to take it out on the open road and find out. Can't do that until the wife gets home from work in about 45 min. I'm the "at home Dad" right now.


Thanks for all the input. That's not something I would have thought of myself.


AJ

[This message has been edited by AJ_92RS (edited November 11, 2001).]