I have a 97 EB Expy with the 5.4L Triton in it. The problem is with the PCV, I had a Motorcraft in it when I bought it and it was buzzing at idle. I went to the local parts house and got an aftermarket Purolator and installed it. The buzzing stopped and I thought, Horray!!!!. I then took a trip to Tennessee, When I got to my cabin in the mountains, I noticed that it was buzzing again, so I replaced it again! Now not even 2 months later it is buzzing again!!!!!! This is getting pretty rediculous! Has anybody else had this problem? Am I alone on this? It is so loud, that you can hear it inside the truck with the windows up. It only does it at idle, and if I pull it out of the valve cover,it quiets down. Is there any aftermarket modification I can make to this thing to make it stop? TIA !

 

My Expy makes a whine noise at idle also, even after the engine is warm. I have no idea why it makes that noise and would be grateful to get a solution to stop it...

John B.
1998 Expy 4.6

 

If yours is coming from the pcv also, I have found a solution. If you start the truck and gently squeeze the elbow at the pcv, you will notice that the noise will stop. The problem that I found ,is that there is too much vaccuum going through the PCV. If you restrict the flow a bit, it stops buzzing. Now for the cure: This was what myself and the Advance Auto tech came up with, you can try to find a smaller pcv with the same size bottom end, but a smaller top end, thten get a smaller hose to go from the pcv tubing to the new pcv. Or you can do what I did, Get a small hose clamp, pull the pcv out of the valve cover, next pull the elbow off the plastic tube that goes to the intake. Next slide the hose clamp onto the longer part of the elbow, now insert the pcv into the side of the elbow with the clamp on it. Next replace the pcv back in the valve coverand connect the tube back to the elbow. Make sure it is tight! any leaks will cause a rough idle or stalling! Then start the truck , with a screwdriver, turn the screw on the hose clamp until the buzzing stops. Don't close the clamp completely, but restrict the flow enough to make it stop buzzing. Close the hood, and you're finished. My truck idles smooth as silk, with no annoying buzzing!

 

Thanks 4by4 freek...I'm not one to venture under the hood with the exception of checking fluid levels, but maybe I'll give this on a try...

John B.
1998 Expy 4.6

 

Thanks 4X4! I will try that. I have 92K on my 97 and it is annoying as hell!

Thanks,

Bob