Posted by Brian on November 05, 1998 at 18:20:57:
In Reply to: Heater diagnosis posted by Matt S. on November 05, 1998 at 16:22:19:
If, after checking the panel & cables as mentioned in the other reply and there are no heater hoses crimped, you still do not have heat try these....
Several possibilities:
1. Yes, the heater core is possible, but, if your p.s. floorboard is not soaked with anti-freeze, this is unlikley. When a heater core goes, it usually involves a leak...
2. Check your thermostat. Make sure it is opening up (to check this, drop it in a pot of boiling water, if it opens, it is good). If the stat does nothing in the boiling water, replace it.
3. Check the thermostat temp. If it is a cold one (example, 165 or 180 degrees) replace it with a 195 degree model. This cured my heat problem really quick!
4. This one is kind of rare, but, it could be "cooling system vapor-lock." Essentially it is just an air bubble in the cooling system. Hard to find, easy to fix. The best fix is to have a back-flush tee installed in a heater hose. Add anti-freeze to the system thru the tee while the engine is running. It will eventually beltch out an air bubble.
: The heater in my 73 Mav. 250 doesn't seem to ever get warm. The fan works fine, it just blows out cold air. I have read some postings here about the "heater core"; does that just need to be replaced? If anyone could give me the skinny on how or what I need to do I would appreciate it, and you will get a "thank you" post (I'm not ungreatful).
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