Evap system hiss....need input!

I've been having a real anoying hiss coming from the driver's side on my X Sport Trac. It seems to be more present when the weather gets cooler and sounds like a vacum leak. It goes away as my revs go up and dissapears when my revs go down. At first at idle the hiss would go away when my AC clutch engaged or after 20 or so seconds. Finaly it stayed on long enough so I could see where it was coming from.

It's coming from a small roundish module about 2"x2"x4" that has two vacum hoses about 1/2" in diameter and an electrical plug. My friend who's a mechanic says it's part of the evap system (regulator, or something of the sort). He says it should only be on when driving on the highway and should throw codes if it's bad......any thoughts?!?!?! It's driving me the hell crazzy and I'm wondering if replacing it will solve my problem.

Sounds like you may be describing the EGR regulator. However, I don't see what year your Sport Trac is, so I don't know what yours should look like.

-Rod

It's a 2004 and the module is mounted on the driver's side fender well. There also seems to be a smaller line coming up beside it caped off with a green cap (not sure if it's connected I just peaked at it quickly). I'll try to take a picture of it tonight. Anyone know where someone might find a diagram of the modules located under the hood?

Denis

Figures, I don't have any manuals that new.

Sounds like you might be looking at the canister purge solenoid though.

-Rod

Hi Rod,

I was hoping you'd have something. I kinda figured if someone had something on Fords you would. I'm going to keep playing with it to see if I can figure anything out. So far I've talked to a shop supervisor I know at a local dealer and he said sometimes you can get vacume noises that wont go away by changing parts. We'll see.

Thanks anyway!

Denis

Any chance you could post a picture of the suspect part? That may help to identify it. Also, if you have access to a scan tool that can access the Ford PIDs/CIDs/Component Parameters, you can check the EVAP system checks to see if any of the devices are failing. A failed component parameter will not necessarily cause the check engine light to illuminate, but may indicate if the hiss is a problem or not.

-Rod

Here's a link to both pics I took (took the pics in a hurry hope it works). It's the module right behind the tube with the green cap on it. The first pic is a close up of the module. The second is more to show the location

http://i234.photobucket.com/albums/ee158/denisbourque/IMG_0348.jpg

http://i234.photobucket.com/albums/ee158/denisbourque/IMG_0349.jpg

If you need a better pic or can't open, let me know and I'll try to figure something out.

Thanks a bunch,

Denis

That is the Vapor Management Valve for your Explorer. It is part of the emission system. Seems like the valve leaking would cause the check engine light to come on though. The little green cap is where you wpuld introduce "smoke" to the EVAP system to search for a leak.

That's what I tought that was and I figured it should throw a code if it was FUBARed. I don't think it's leaking via the vacum lines because I tried to wiggle them and the wistle didn't change sound, so I'm gessing it's the air flowing inside that's causing the wistling. Maybe a seal inside causing turbulance when the solnoid is open or such.

The shop manager did say that some model vehicles produce sounds that are normal (if you will) and can't be helped. Maybe this is one of those. Just very anoying. I'm going to try to find a cure myself because every time I have it in to be looked at they charge me labour because there was no actual problem found......Maybe I can sell my fix to them if I find one.

Denis