cleaning my air filter. After I finish I usually let it sit and idle for about 10 minutes while I clean up. As I was cleaning I noticed this strange noise coming from my engine. I get closer and it was something I had never heard before coming from my engine so I knew something wasnt right. It sounded just like a hose from an air compressor. I was listening to that for about 10 minutes puzzled on what it was when all of a sudden the idle on my truck begins really roughly then all of a sudden it turns off. WTF!

I let it sit off for about 5 minutes and I turn it back on. Right off the bat the idle is extremely rough and I could tell it was about to choke again so I turned it off.

Do you guys have any idea what it is? It sounds like it was coming from the middle of the engine bay closest to the firewall.

blehhhhh

 

its hard to say without listning and lookin at it, but make sure all ur sensors are pluged in. if u took the air filter out u may have unpluged the maf sensor. push down on all the plug wires and make sure there connected at both ends.

 

Check the crankcase vent hose. Its a hose coming off of the engine and it connects to the intake tube after the maf.

 

You did refill it with oil right?

 

lol yes I did. 4.5qrts plus a tad extra..I checked the hose goin into my intake and that was fine.

I turned it on again and revved it a little bit and the idle seemed to get better after a little while..Then I noticed if I was idling and I hit the gas and let off, the rpms stay at about 1.5 then after like 10 seconds it goes down to 1 or slightly less...when I let the gas off its acts like im actually hitting it slightly even though im not



I have been noticing a rough idle for about a month now, I just never let it idle as long as I did so maybe this has been a problem for a while and I just now noticed since I let it idle that long

 

It may be time to clean your throttle body and maf with some air intake cleaner.

 

that still doesnt explain the sound...you know what an air compressor sounds like when you blow air out...thats the same exact sound its making.

 

Check your intake. Make sure its on all the way at the throttle body side.

 

The symptom is the sound of rushing air. That EXCLUDES any wire connector problems or dirty sensors.

Check your entire intake system for loose connections. If the intake hose wiggles at all on the throttle body or MAF, tighten the clamps. Check all of the VACUUM hoses that connect to the intake manifold.

One of these has to be loose, and it's allowing excess unmetered air into the engine, causing it to "choke" out.

 

sounds like unregulated air getting into your intake. i thought i could drive my truck to the store one time to pick up a new egr valve with my old one off. nope the truck runs like crap and dies.

 

I know the hose going into my intake has never fit snug. Its been out about a quarter of an inch(maybe a little less) since I installed it since it couldnt reach...but i mean ive had my intake on for 3 years.

I just got back from the gym and it drove fine. I think as long as I dont idle for a long period of time im ok for now. Im calling ford tomorrow for my recall and im just going to tell them to check that out when I take it in hopefully this weekend.

 

my money is on a loose vac hose

 

yea thats what I was thinking it was

 

Take a piece of rubber hose about 2' long and put one end to your ear and move the other end around the engine compartment (with the engine running) until you locate the loose/cracked/broken vacuum hose/fitting and then replace it. It might be a good time to go ahead and inspect all of your vacuum hoses and fittings cause they tend to get dry and crack, especially if you frequently wash the engine bay.

 

I dont even know which hoses are vacuum hoses. Never really looked. Im sure it wont be hard though. Someone said take some of berrymans carb cleaner and spray the hoses and depending on if their is a leak, it should either spike the idle or stall it out

 

ok well I found the problem..its on top of the engine bay middle like I said..its a little rubber tube about 6 inches (90 degree bend) and had some oil in it...I dont know if thats a bad thing. Has two hoses connecting to it which I think is just water. Its all cracked in multiple spots. I cant get a replacement part for it until fords open next and thats not til tuesday.

anyway here is a pic to get a better idea of where it is.

 

Any chance you could zoom that in? I can't see anything in at picture! Take a pic of where it connects and where it goes.

I may have a spare if you give me the length and ID of the hose.

 

I just checked my 03 and it goes down to the valve cover . Looks like into a PCV valve.

Edit
The large end is 7/8 and molded down to about 3/8 to the pcv valve.

 

ya sorry thats a really old pic...ill take one when my parents get back..they borrowed my truck to take some junk to the dump

 

That sounds like you have a vacuum leak on the engine somewhere. that would have to do with your intake. Check all your intake manifold gaskets, then check all your vacuum hoses, then check to make sure that you have a seal on the airbox, and that the air hose is sealed shut too.

 

ok here we go guys..

as you can see the elbow piece collapsed on itself. Then at the base of this thing where the sensor is its all cracked so im going to have to get a whole new piece it looks like

 

what sensor is that?

 

I have no idea..I just added in some colors to show u guys more..the arrow is pointing to where that sensor is and the green line is where its all cracked

 

Mines running the exact same way, i have an intake vacuum leak.

 

It's not a sensor guys. It's the PCV valve (Positive Crankcase Ventilation). It's a simple device that allows vapors from the crankcase to flow into the intake and be burnt up in the combustion chamber.

I believe your particular application uses a water hose that wraps around it to warm up the PCV valve. This is visible in the image above. Don't be alarmed when you remove the PCV valve by a U-shaped metal hose that surrounds the rubber grommet. Make sure you put the new one in the same way the old was removed.

The PCV valve is available at any auto parts store for a few bucks. It looks like this:

Due to the large size of this valve and the hose connecting it, any loose fittings will cause a rough idle condition and poor low-end performance. Replace the PCV valve by simply pulling it out of the rubber grommet and disconnecting the rubber vacuum hose from the intake manifold.