Heater problem
Thread Starter
Heel & Toe
Joined: Mar 2008
Posts: 18
Likes: 0
From: lakeside california
Heater problem
Heres one I hope someone can shed some light on.The heater in my 85 comes on under acceleration/load with the selector turned off.I replaced the control valve with no results. This started after replacing the heater core. Any input would be appreciated thank you
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
This sounds like the door is not closing all the way. Under the increased horsepower hot coolant pressurized by the water pump may be forcing it's way past a semi closed door.
Check the linkage, and woe is you if the door has an internal blockage keeping it from closing. You've changed the heater core once.....
Check the linkage, and woe is you if the door has an internal blockage keeping it from closing. You've changed the heater core once.....
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
headaches, with the car running, have someone move the selector lever to heat, observe what the control valve does. With the car at operating temp one hose3/4 I think should be warm, the other,5/8, should be cold,well cooler. When the valve is opened both should get hot.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
Door, Valve......what ever that thing is that shuts off the flow of water when closed.
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
Why are you going into the heater core until you have exhausted all other possibilities? Seems to me the heater core is doing its job, hot water in --heat out. You have to determine how the core is getting hot coolant with the heater in the off position.
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