Air Problem/Vacum.

[RIVERA RACING]

I have a 04 Expedition when I put the air from the front panel and I drive under a load the air stops coming out the panel and goes to the defrost on windshield by its self any Suggestions..................help please.

 

[stamp11127]

Vacuum leak is the usual cause. Check the lines in the engine bay for dry rotted hoses.

 

[RIVERA RACING]

I've check and cant find nothing.....

 

[Hamfisted]

Look under the hood on the passenger side near the firewall. Most leaks are up in that area. A common one is the supply line going IN the firewall there under the PCM box, another one is the hot water valve control line that comes OUT of the firewall and attaches to the hot water valve. It gets knocked loose a lot when people change the sparkplugs on that side. Or sometimes the lines just crack with age and break loose.


-Mike