Jaxem

iTrader: (3)

So i've had an issue for a while now, my HVAC always has hot air coming out of it. The blower turns off, but there's a moderate trickle of air that comes out anyways, enough to the point that my legs are always sweating. There's also a smell of gas/exhaust when i come to a stop and the car is idling, quickly enough that it seems to come in through the HVAC almost (though my exhaust guy say i don't have an exhaust leak)

The car also has symptoms that make me think it also has a vacuum leak (bucking at low speeds, idle all over, high BLM's on one bank 2)

My question is, is it possible or even probable that these are coming from the same place? I know the HVAC actuation is run off vacuum, so would having a vacuum leak in the HVAC system maybe keep the door from closing all the way and let heat in?

I'm just hoping they're related so maybe i can get two problems fixed with one repair.

Spartan7

iTrader: (7)

The directional doors are indeed driven off engine vacuum. However, the mixer door (hot/cold) is controlled by a cable linkage from the HVAC control **** to a cam on the bottom of the mixer door hinge. If your linkage is binding or snapped, it may be stuck open to full heat.

HVAC has nothing to do with a fuel smell, although I would say if you have a suspected vacuum leak combined with an exhaust leak, it will burn rich and smell like it.

Kevin97ss

Check your PCV system, it can smell like exhaust fumes if its open. With no recirc option in floor mode those fumes can enter the HVAC system while driving. Also check for an exhaust leak by the HVAC box under the hood, there is a water drain in the bottom of the box above the frame rail that is open to the inside vents.

trilkb

iTrader: (4)

Put it on recirculate?

Kevin97ss

Recirc, or recirculate is only available in the max a/c position, which, if memory serves is panel vents only.

trilkb

iTrader: (4)

Have you tried it?

Turn the system to max ac then shut it off, the recirc panel will stay shut. Normally this solves are coming through any vents if you're moving. If your stopped and still getting air flowing with the system off then I have no idea lol

Kevin97ss

I guess I skimmed past "the blower turns off", and got the impression he had it set on floor. You are correct, the recirc door should be closed when the system is off.

Jaxem

iTrader: (3)

I'll check into everyone's suggestions and report back with whatever i find, thanks for the input so far guys!