My F-150 has developed a rattle and vibration at idle that only occurs with the truck in gear and stopped (with the brake depressed.) The noise appears to be coming from the front of the truck, perhaps from the driver's side (though it's difficult to tell while sitting in the cab).

Before I go crawling around underneath with my son holding the brake while the truck is in drive, I'm wondering if anyone else has had a similar issue--I would sure like to know where it might be best to point the flashlight.

~Steve

 

I have a 2006 4x4 with the same issue. Mine will rattle more loudly and then quit if I bring the rpm up to about 1k when I hold the brake down. It will also occasionally make the noise while driving under slight acceleration, but quit when the rpm gets a little above 1k.

 

Unless you're convinced the noise is underneath, be sure to check your windshield cowling. Wedge some foam or something between it and the windshield for a quick test, I spent a lot of time hunting an in-drive brake applied "rattle" only to find this was the culprit! Good luck.

 

Ty, I will check the cowling, but I think the noise is coming from under or maybe from the front left wheel area. It also is worse when it is cold or semi-cold outside.

 

Check you PCV valve. Going into gear with the brake depressed will affect vacuum...which the PCV valve is directly affected by.

 

heat shields over muffer / CAT / exhaust ?

 

I made sure the cowling is in place, but no dice. I will check the exhaust components and the pcv valve.