Cadillac Owners Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
1,162 Posts
Discussion Starter #1
Im my 85 FWB w/ 4100 the heater is not working the way it should. I replaced the heater water valve (the one located by the trans. dip stick) with no success. The temp door is operating the way it should be.

If I set the temp to 80 or 90 the cabin will get warm, but when I turn the fan on (set at the above temps) the air is not warm. Could this be a heater core problem or am I looking at something else?

Any help is always appreciated guys. Thanks in advance.
 

·
Registered
Joined
·
319 Posts
sounds like the door that opens to let fresh air in isnt closing like its supposed to when u turn the fan on. probably an easy fix if u can find the motor that opens and closes it.
 

·
Registered
Joined
·
6,471 Posts
Check your heater hoses. They should both be HOT, not warm, but HOT. If they aren't:
1. If both are cool or only warm, most likely cause is a bad thermostat.
2. If one is hot, and one is only warm, most likely cause would be a clogged heater core.
You should also make sure the coolant is up to the proper level since this too, can have an affect on the heat.
 

·
Registered
Joined
·
7,534 Posts
Cadillacs for some reason seem to have a higher than usual heater core plugging problem than other GM cars that I have owned. But then again, all my cars I have owned and maintained since low miles, and the Cads were much older. Likely just lack of maintenance. I typically backflush my cars once a year with the Prestone kit. And refill with distilled water!!!
 
1 - 5 of 5 Posts
About this Discussion
4 Replies
4 Participants
N0DIH
Top