Click, click, click....

I recently notice a 'clicking' sound as I accelerate my 2001 E150 XLT 5.4 ( 210,000 miles ). Happens only in very cold weather and then only until the engine warms up. When temperature more moderate, no clicking at all. Only happens when accelerating and only at low RPM.

Thoughts?

Exhaust leak?

On my 2005 with a V-10 it used to make a clicking noise. Discovered it was the engine tuning itself. The exhaust manifold bolts were popping off like popcorn. I only have a total of 3 bolts holding my manifolds on but it runs great. Same gas mileage for the last 120,000 miles.:runaround: