Stinky A/C

[rmkeen]

I have a 2002 Trailblazer w/4.2L. Under medium to hard acceleration an exhaust like odor seems to come through the AC vents. Under steady state speeds, the odor is intermittant. Any Ideas?

TIA

Bob

[snoman]

Sure it is the exhaust? What happens when blower is on hi? (I have a idea)

[Bluesman123]

OK...here's my guess.....

 

You have a very small vacuum leak. Not enough to trigger the MIL but enough so that when your engine vacuum falls (under medium to hard acceleration) the vent flapper valves start to close. That sends a puff of air through the defroster vents (the default with no vacuum assist), which haven't been used in quite a while. They are beginning to get a bit funky, but you don't smell it because they are usually closed.

 

1. Check to see if you are leaking just a bit past the 1-way vacuum valve that goes to the accesseries;

 

2. There is a product (name forgotten) that you can spray in the vent intake just in front of the windshield to freshed up your "fresh" air system.

 

How is that for a WAG ??

 

Dave

[snoman]

OK...here's my guess.....

 

You have a very small vacuum leak. Not enough to trigger the MIL but enough so that when your engine vacuum falls (under medium to hard acceleration) the vent flapper valves start to close. That sends a puff of air through the defroster vents (the default with no vacuum assist), which haven't been used in quite a while. They are beginning to get a bit funky, but you don't smell it because they are usually closed.

 

1. Check to see if you are leaking just a bit past the 1-way vacuum valve that goes to the accesseries;

 

2. There is a product (name forgotten) that you can spray in the vent intake just in front of the windshield to freshed up your "fresh" air system.

 

How is that for a WAG ??

 

Dave

A interesting possible solution!