88 corvette help
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Joined: Jul 2009
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88 corvette help
can anyone help with an issue i have.When I drive the vette down the road accessive heater is coming out from under the dash and feels like its coming from the heater eventhough the heater is off.When I turn the heater on it seems to make the car miss so I dont know whats going on please help
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
My '88 IROC-Z has a heater control valve in the coolant line to the heater but my '88 Vette has no such valve.
If you drop the RH hush panel and look up under the dash near the large HVAC plenum you will see the Temperature door control motor. There is an "L" shaped rod sticking out top of this motor with a white plastic retainer that holds a rod which goes into the plenum and attaches to the Temperature door.
Check to see if the "L" shaped rod is indeed connected to said control rod. If not you just need to find/fab a new retainer.
If the rod is attached, run the HVAC in Auto mode and run the temp control up/down while watching the "L" shaped rod; it should rotate as you change the temp setting.
If not, the problem is in the HVAC control head or the motor is burned out.
Hope this helps to isolate the heater issue; sorry but I can offer no suggestions about the rough idle at this point.
If you drop the RH hush panel and look up under the dash near the large HVAC plenum you will see the Temperature door control motor. There is an "L" shaped rod sticking out top of this motor with a white plastic retainer that holds a rod which goes into the plenum and attaches to the Temperature door.
Check to see if the "L" shaped rod is indeed connected to said control rod. If not you just need to find/fab a new retainer.
If the rod is attached, run the HVAC in Auto mode and run the temp control up/down while watching the "L" shaped rod; it should rotate as you change the temp setting.
If not, the problem is in the HVAC control head or the motor is burned out.
Hope this helps to isolate the heater issue; sorry but I can offer no suggestions about the rough idle at this point.
Race Director
Joined: Dec 2003
Posts: 14,134
Likes: 935
From: Fremont Ca
2022 C4 of the Year Finalist - Modified
Based on an 84 I owned years ago the valve was controlled by vacuum so this may be the cause of a vacuum leak if in fact 1988 has the same type of valve,it should have.Something stops the water from circulating through the heater core when the heater isn't needed.
