The heater only blows through the defroster on the top of the dash, and it makes a weird noise when it is on. it makes a noise like a blow by valve on a turbo. any hints

 

I would say you have one of the internal deflector stuck in the closed position in your air duct. Good Luck with that one!!

 

The flaps that direct the air are vacuum operated. So start with checking for vacuum leaks. This means engine vacuum leaks also. Start at the vacuum resivoir behind the front bumper(passenger side) and work back from there.

Also check the vacuum switch in the heater controls themselves. This may be the culprit for both problems.

 

i will try and have fun with this 1 i guess...

 

Check the vacume line down on the side of your intake manifold and work your way to the HVAC unit from there checking for cracked or loose lines.

 

Vaccum is your problem My old heep had the same prolem GOOD LUCK FIXING IT>

 

im guessing thats whats wrong with mine. i had to put in a different heater control since mine got all busted when they tried to steal my radio. so i know thats all connected. my heat likes to switch from floor to defrost and back down again.