Has anyone ever heard a humming sound coming from the engine while it's at idle? It sounds almost as if someone is holding a ziptie or something plastic up against a fan. I looked and nothing is hitting the fan. It goes away when I rev the truck, or atleast I cant hear it anymore. I can hear it in the cab even. I may be wrong but it sounds like it's coming from the top portion of the engine. Its not so much the sound that bothers me but I just dont want something to go wrong... Any suggestions on what it could be?

 

leave the hood open - shut it off - get out and listenfor the noise right after you shut it down..I bet its the EVR

 

Check your belt as well. Might just need some silicone spray on it to make the sound go away.

 

Do they make silicon spray that you use on a serpentine belt? I have some of that Carquest belt dressing but , it says on the can not for use on serpentine belts ?? Yeah , just wondering if theres different stuff out there and what it's called..?

 

Seems like it comes and goes here in the past day or two. It kinda sounds like it's winding down (if that makes any sense) when I turn off the key so thats what kind of made me think that it could be the belt. But I dont know...thats just a hunch..

 

Shoot you gotta 5.4L - I'm pretty sure its your EVR ross - heres an easy test -


First, pull your throttle body cover off that says -

Leave you hood open and start the truck , let it run for about 10 seconds then shut it off, hurry up and get out and go look under the hood for the EGR Vacuum Regulator (EVR) , it's between your Throttle Position Sensor (TPS) and your Differential Pressure Feedback Exhaust Sensor(DPFE) and quickly put you hand on top of the EVR, This -



If its making the noise, it will be vibrating and you'll be able to feel it doing so..

 

If not the EVR, check the PCV valve. mine was loud enough that you could hear it outside the truck walking past it when it was idling. leave the truck idle until it makes the sound, leaving the truck idle, pop the hood and check the PVC valve on the passenger side valve cover, it has a large(r) hose going to it, it just pulls out of the valve cover real easy and takes about 45 seconds to replace ~$5.

 

Thanks for help guys and thanks for the pics jbrew...

Ill probably check it this evening...

I've got 160k on the truck and Its never really had a good tune up. I bought it at 100k for $5k. It was a good deal because the truck was in good shape. I just wasn't sure on the maintenance record for it. I just replaced the plugs in it this weekend for the second time in its entire life. It seems like more and more things keep going wrong with it. Its a good truck and I want to keep it running...

 

You can also check your PCV valve by disconnecting it and shaking - if it sounds like an empty paint can when you shake it - it's good.

This time of year with colder weather - condensation can screw them up, might be a good Idea just to change-it out like was said..

Check out this line as well - they have been know to split or collapse. The rubber 90 degree elbow back by the firewall.. -

 

Ok...Jbrobeck gets the prize on this one... Its the PCV. Its rattling where it connects to the valve cover. I noticed it had popped out when I was changing the plugs on the engine. Its the culprit here though...

So, just take the actual valve out of the hose and replace it? I'll probably go to auto zone to get it. Thanks again for the help and thanks for the pics, jbrew. It always seems more helpful when you can actually see what your dealing with. BTW... what's your truck look like? Seems like I know what everyone elses looks like but yours...

 

Good to hear you found the source. If it hadn't happened to me I would not have been able to help you out quite the same! You just pull the valve out of the tube, be sure to check the tube, as JBREW said, the hoses over the engine have a tendancy to split and you could be chasing gohsts. when you buy the new PCV valve, if it looks a little different, don't worry too much, just make sure it is listed as the correct part for the truck as I believe they are supposed to flow a specific amount of air.

Later

Josh

 

Did he pay you to say that lol

Kidding , glad you gotter fixed