Have a 2007 F-150 5.4 3v with 130000 miles. Runs great, religiously change oil with Pennzoil UP, take good care of it. Anyways the last 2 years (20,000 miles) it’s had some sort of an exhaust/catalytic on and off tick I can’t pin point to save my life. The noise resonates between manifold and passenger side converter with the stethoscope and under the passenger door standing away from it. Don’t hear anything in the wheel well other than injectors and VCT ticking if it’s real hot.

This truck has had the full timing job already, updated VCT solenoids, new plugs, coils, injectors (all motorcraft).

When it’s real cold or hot it won’t do it. It’s the worst while warming up. Starts about 20-30 seconds after starting engine and starts ticking/tapping as things start heating up. It’s and on and off rhythmic soft metal tick. “aka 7 ticks then stops for a few seconds, then ticks a few more times, stops, then starts etc”. Vehicle runs great otherwise and has no drive ability concerns or CEL codes. Definetly strange and just curious if anyone else heard this. Already loosened the converter heat shield band and it’s not that either.

I only drive this vehicle when going several hundred miles from home. If I was local I’d just live with it but don’t want something breaking down while away with a trailer etc...

I’m thinking something broken in the cat or a sticking lash adjuster maybe? Only reason I lean away from lash adjuster is it’s so intermittent and temp related. Also has that exhaust tinny sound. Hasn’t gotten any better or worse since it started randomly one day about 2 years ago.

 

 

Ended up being a broken bolt on passenger exhaust manifold. Was just resting in there loose. New stainless steel bolts and all quiet now.