Need some help in diagnosis here. We have a 2006 4.2 that has a ticking noise, it sounds like and exhaust leak. It tends to do it only in drive, when you put the selector back in neutral it goes away. It seem like its coming from the front of the engine. When it's cold it doesn't do it until a few minutes later, but really noticeable in gear. Any advise on this?

 

Check the engine lifting bars that are bolted to the exhaust manifold. Mine did the same thing you are describing and I noticed that the flat lifting bar was vibrating while in drive but not neutral. Tighten the bolts on the manifold and that fixed the problem. The bolts are not easy to get to. Someone else had the same problem, I read about it in a truck forum.
Terry

 

I have the engine removal bar vibration - rattle. It sounded like it was coming from a pulley along the belt. A qualified mechanic figured this out for me. Soom to be fixed. Also I have a cold weather tick when the engine is first started. The tick varies wih rpm and goes away about 5 minutes in to the drive (well warmed up). I think this one is a valve train noise.

4.2L 6, 2007 150 XL 5 speed.

 

Wow, another '07 V6, 5 spd! These are collectors' items now, don't ya know?