Heater Problems
Thread Starter
3rd Gear
Joined: Jul 2001
Posts: 3
Likes: 0
From: Dallas, Texas, The Great US of A
Heater Problems
I have a 1989 and was driving and kicked on the heater and got nothing but cold air blowing (car temp was 170-180). Just wondering where to begin on this problem. Thanks in advance for any help
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Re: Heater Problems (dink911)
Maybe need a new thermostat.They can get stuck open..is 180 temps low for your car or did you do any fan/cooling mods?
Is that highway or city driving full warmed up?
Is that highway or city driving full warmed up?
Thread Starter
3rd Gear
Joined: Jul 2001
Posts: 3
Likes: 0
From: Dallas, Texas, The Great US of A
Re: Heater Problems (dink911)
I was on the highway. Car was fully warmed. That temp is low, but it was 45 degrees outside so I thought that should be normal. (I had been driving for about 1-2 hours).
No mods on cooling system. I am running some new kind of antifreeze (king Purple)
No mods on cooling system. I am running some new kind of antifreeze (king Purple)
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Re: Heater Problems (dink911)
Do the heater hoses feel hot at the firewall?
Check the operation of the heater control valve.(located where the 2 hoses enter the firewall by the blower housing).
You should be able to manually push the plunger to the open position with the vacumn line disconnected.
Check the operation of the heater control valve.(located where the 2 hoses enter the firewall by the blower housing).
You should be able to manually push the plunger to the open position with the vacumn line disconnected.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Heater Problems (rodj)
No heater control valve on an '89. If both hoses feel hot, coolant maybe passing over the top of the core, but not through it. Try flushing it and flush your entire system if it hasn't been done. To make sure you get everything out after the flush, pull the lower radiator hose and the oiler cooler hose at the block (you can also pull the knock sensor, but doing the above should get 99% of everything out). If you still don't have heat when your done, the core may be plugged.
Thread Starter
3rd Gear
Joined: Jul 2001
Posts: 3
Likes: 0
From: Dallas, Texas, The Great US of A
Re: Heater Problems (dink911)
The hoses are hot. I had the system flushed and no heat stiil. If the core is plugged please tell me I dont have to pull the core.
Thanks for advice.
Thanks for advice.
Burning Brakes
Joined: Oct 1999
Posts: 843
Likes: 2
From: Nashua New Hampshire
Re: Heater Problems (dink911)
If you do have to replace the core, check my web site below. I have a link to a page where I tell how to get the passenger carpeted kick panel out (with pictures). It's actually not that hard. Once you do, the heater box is right in front of you. You'll just have to remove a few additional items (there's a cross-brace and such). The process is a bit simpler than http://www.corvettemagazine.com's article on how to replace the core. They said you'll fill up a swear jar to replace it. It was simple enough to remove the kick panel that I'll think I'll replace my own core when it goes. I est it'll take about 45 minutes to remove everything to get to the core, and 30-40 minutes to put everything back together. I only needed a few tools (magnetic 7mm socket, 13mm socket, etc). I don't know how hard though it is to actually get the core out and a new one in.
Burning Brakes
Joined: Dec 2000
Posts: 1,161
Likes: 0
From: Orangeburg, NY
Re: Heater Problems (dink911)
There are several possibilities. The vacum line to the control unit may be cracked, broke or disconnected.It is located under the distributor.At that locaton there is a t in in the lines. Make sure the t is properly connected to the lines. The t becomes old and breaks after a while causing a leak and ultimately the vacum control unit dos not get the proper vacum.
You may be having a problem with the temperature door inside the heating a/c air housing unit (located in the engine compartment on the passenger side of the car, attached to the fire wall). Remove the electrical connection on the top and remove the module. Look inside and you should see a door connected to a rod. The door moves from side to side to cover either the heater or the a/c core. The door may be covering the heater core for one of two possibilities. 1- the rod connected to the temperature door actuator may have a broken clip or 2- the vacum control unit may not be working properly. If you can move the door the clip is broken. If you cannot move the door the vacum control unit is in need of repair. Check out the first suggestions, if they are not the problem e-mail me.
You may be having a problem with the temperature door inside the heating a/c air housing unit (located in the engine compartment on the passenger side of the car, attached to the fire wall). Remove the electrical connection on the top and remove the module. Look inside and you should see a door connected to a rod. The door moves from side to side to cover either the heater or the a/c core. The door may be covering the heater core for one of two possibilities. 1- the rod connected to the temperature door actuator may have a broken clip or 2- the vacum control unit may not be working properly. If you can move the door the clip is broken. If you cannot move the door the vacum control unit is in need of repair. Check out the first suggestions, if they are not the problem e-mail me.
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Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Heater Problems (89 Bob L)
Bob L has good suggestions for checking it out further. If those items are ok, try flushing the core independently of the system. Disconnect both hoses and connect a couple of pieces of heater hose. Run water through each. You can also try compressed air, though you really don't want to exceed 25 psi because you could end up with a leak. After replacing my core, I put 125 psi to the old one and with a loud pop, it finally unplugged. Wonders of wonders, it didn't blow up.