hey guys when i put my heat on it only comes out of the dash and not out of the vents at all, even if its on vent. now is there sonthing wrong here or is this how these cars are? also if so how coudl i fix this?

 

the defrost is the "default" position.

the vents are operated by engine vacum, check to make sure all the vacum lines are hooked up that come out of the heater box thing in the engine bay.

is there a hissing sound coming out of the heater control panel?
if so then there is a vacum leak there.

 

Mine did that same thing...

 

The air control doors in the HVAC system are positioned by vacuum actuators. Each outlet and bypass door in the duct work has a small vacuum diaphragm motor that operates the door open or closed (except for the temperature control door, which is direct-cabled). Each of these vacuum motors has a spring to return the door to its "home" or default position. Applying vacuum moves the door one way, removing vacuum allows the spring to return the door the opposite way. When the system is in total default, air will discharge through the defroster outlets only.

The HVAC selector position switch is also a ported vacuum valve that routes the vacuum to the correct door for defrost, heat, A/C, MAX, Bi-Level, etc. The source for the vacuum is the intake manifold or plenum. There is a small (about ¼") hose connected to the intake. If this hose is disconnected or damaged, the HVAC controls will assume their default positions, causing all air to exit the defroster ducts. The defrost position is the default so that if the system fails, driving safety can still be assured since the windows can be kept clear.

Under normal circumstances, when the HVAC controls are moved to a different position, you should be able to hear a slight hissing noise inside the vehicle as the vacuum is vented from one motor and routed to another. If you don't hear any noise when the control is moved, chances are that the vacuum source hose is disconnected, connected incorrectly, or pinched or damaged in the engine compartment. If you hear a constant hissing noise, there is likely a vacuum leak inside the passenger compartment. This can be from a disconnected or damaged hose, or a failing ported vacuum valve in the HVAC controls. In either case, you would need to remove the HVAC control cluster and/or the lower instrument panel trim to access the hoses and controls.

This sounds like your situation. It is caused by a lack of vacuum to the HVAC controls or a failed vacuum switch/valve in the HVAC conrol head on the dash. The vacuum is routed through a small plastic line through the firewall and to the control switch.

Check for a small hose near the firewall that is disconnected, kinked, melted, cut, or otherwise damaged. On a TPI engine, the vacuum source is at the fitting on the right side of the plenum, directly behind the vacuum fitting for the fuel pressure regulator. If you do not find a hose problem, you'll have to remove the control and check for vacuum at the control switch/valve. If a vacuum supply is present, turn the control to different positions to test whether vacuum is ported to the correct line in a given position. If the vacuum just leaks out all around the control, you'll have to disassemble, clean, and regrease the control valve with silicone grease. You could replace the control, but it is likely a dealer-only item that is not in stock. Unless the control is completely broken, I would try the cleaning and regrease. It's worked for me.

 

camaros have a problem of losing vacuum in the heating check the pressure in the lines

 

mine is hissing inm the hot possition. is that a vacumn leak? thnks