Yet another tappity-tap thread...

[JohnStra]

I've read through several engine noise/tapping threads, but haven't found any that quite match my sound. This is for a 92 V6 truck (3VZFE). Here are the symptoms...

At cold idle, tapping sound is in rhythm with engine RPM - not terribly loud.

Under load, there is a general rattling that sounds like valvetrain. This sound gets loader as the engine warms up.

At hot idle, engine sounds like a little diesel.

I listened closely with a scope and I hear the sound best right on the driver's side exhaust manifold. I also hear it well (but not quite as well) if I put the scope right on one of the driver's side head bolt. I can't hear the sound well at all from the bottom end.

I'm thinking either a lifter or a small exhaust leak.

Thoughts?

[Your Uncle Moe]

The tapping sound is only at cold idle? Are you sure its not a noisy lifter?