I have a 99 F-150 V-6 109,000 miles, has been a great 1st American made truck. It has started making a fluttering noise, coming from engine compartment, most noticeable at stop in drive. Loudest on left side of vehicle near wheel well. Starts after Truck warms, decreases greatly when it's shifted to neutral, increases when the wheel is turned. Exhuast ?? Making trip to Fla. end of week. Help!

 

I have relatively the same problem with mine. It will start about 2-3 min after starting the truck (in park) and will not make it EVER if I am in neutral. When I am in drive and parked, I can hear it - only makes it for a few seconds at a time, but it sort of waxes and wanes and comes and goes without any other warnings. No idea what it is, but I've had it now for 15,000 miles.

If anyone DOES know, please let ME know. I told my service guy to check it out when they were doing my tranny job, and he said that he would. When I went to pick it up and asked about "unusual sounds", I was told that no one heard anything.

 

I appreciate the response. The noise is constant after it warms up. You can really hear it if your are next to a wall where the sound reverberates ,ie. drive thru window, to the point that I put it in neutral so it goes away.Again, it gets louder when you cut the wheel. I have noticed the smell of exhaust fumes when I run the heat or defroster. It seems to run fine and the mileage is pretty much normal. I guess I'll find out on my Roadtrip. I have been told by several people that it is probably an exhuast leak, one even said " Fords just make noises like that". If it is an exhuast leak what are the ramifications.I would appreciate any and all responses.

 

Sounds like the idle air control valve fluttering and needs cleaning. The noise is being transmitted through the air intake which brings air in thru the left fender.

 

Thanks general05, will check it out.