Air Controls

[dcking01exped]

Please help me with a problem with my air flow in my '01 XLT.

Going down the road, passing a car, the air flow out of the dash vents stops when the 4.6 L is under the extra strain. When I let off of the gas, the flow comes back out of the vents as expected.

Is this normal? I've been searching the forum and can't find. New to this forum. Thanks for sharing!

 

[AMERICAN AIR-1]

I've never had that problem with mine(knock on wood), but as a rule of thumb, if the air goes to the defroster ducts on hard acceleration, you have a vacuum leak somewhere.

Listen under the hood with the engine running and listen for a hiss. You may want to look at all the lines coming off the intake. They are bad about collapsing and eventually leaking. If you see one your wondering about, close it off with a pair of needlenose pliers to see if the hiss changes.

 

[dcking01exped]

I'll try it out. Thanks for the help. I'll try and post the results this weekend.

 

[Godfrey]

Hey, I know we're a couple of months out since the last reply to this post. But I was having the same problem. I was just about to post the question and decided to search first.

The vacuum line was actually pulled off. A quick reattachment solved the problem and I was able to recreate the situation again by disconnecting it. Thank you AMERICAN AIR-1!

My problem was that, really at any speed, it would go between defrost vent and back to the front...back and forth all day long and the Expy never got cool.


Thanks again guys! Saved me a trip to the dealer!



Phil Godfrey
St. Louis, MO

 

[dcking01exped]

Godfrey,

Sorry for the delay in my response. I'm glad to hear that your problem was solved. My still remains. Mine is only doing it under acceleration. What line did you disconnect. I'm not sure that I'm seeing the right one. Someone told me that it sounds like the line is collapsing.

What do you think?

 

[Godfrey]

I have a 2004 Expedition with the 5.4L. I am not sure exactly what the line is called that I found. But in my case it was located pretty much near the middle of the engine compartment behind the plastic shroud that covers the top of the engine...near the firewall.


I don't know what could be causing your problem...could it be the result of losing vacuum pressure somehow during higher RPM?



Phil

 

[dcking01exped]

Guys -- Sorry for beating a dead horse, but in my world I'm still chasing this ghost. I've traced all lines, all are fine. I'm being told now that it must be in the dash. Does that sound right? I'm getting closer to taking to the dealership, but I thought that I would try one more time to the group. I know the answer is here.

Thanks in advance.