I have a '99, 4.6, 3:55, auto - stock at this point - with 8,000 miles. Whenever I'm parked with the engine running or sitting in traffic and my window is down, I hear a pronounced "click" from the front underside about every 15 seconds. Sounds like a cat cooling down after you shut off, or someone tapping the frame with a ballpeen, but it's very regular. Anyone have any idea what it is? Thanks.

 

My identical truck did that from 500 miles up to 2000 miles and it finally went away totally. I was told that the exhaust was changed to some different kind of stainless steel for 99 and it expands and contracts which causes the noise. Mine was very loud and I was worried about it, don't worry about yours.

Is the weather cooling off where you are or is it raining when it makes the noise. That may have a lot to do with it.

------------------
'99 XLT S/C 4.6Romeo, Auto, 3.55 LS, Oxford White, Dark Graphite int., Tow Package, Orlando appearance package (Body color honeycomb grill, mirrors, and Lariat wheels) Gave up on the captains chairs!! I'll live with the 60/40 for now
I am taking my Bucs front license plate off until they dump Trent Dilfer again!

 

Thanks, Seacrow. Yeah, it's a little cooler here in Alabama, but not that much. I assumed in was metal convection too, but thought I'd check with you experts.

 

Had a '97 that crackled and popped, but not nearly as much as this '99 has. Got 5,000 miles on it and either I'm getting deaf or the noise has disappeared.

Several others on this list have mentioned how noisy their '99 exhaust system has been, so just be patient. It goes away with more miles on it.

 

Is the A/C on? sounds like the compressor switching on and off.

------------------
97, 4.6, 3.55LS, Dk red 265/75/16, Leer cap, Rhino bed, rose wood dash kit, CD player, High performance cross drilled rotors