( Howdy. My first time on) I have a 95 4Rnr 3vze, 160K - audible clicking under load from left bank - not injectors - - external stethescope indicating #4 cyl but hardly a determination. Checked all valve clearances and both banks, Intakes and Exhausts are in the .009" to .011" range throughout EXCEPT #4 Ex is a tight .005" and #6 Ex. is .007". I expected to find something sloppy, not too tght. All lifters spin freely.

Can this tightness be the source of the clicking? (That'd be weird.) 2) Should I bother to re-shim these two Exhaust valves looser or just leave 'em if not a threat? 3) Do clearances actually tighten up over time - that seems wrong?

Any info someone can offer I'd really appreciate.

 

1. No. Looseness is what could potentially make noise. But 3VZE valves don't even when very loose, in my experience.

2. The exhaust clearance specs are .009" - .013". Yes, fix those ASAP.

3. Yes they do. Because the valve seat and the portion of the valve where it contacts it are the major wear points. Over time the valves, usually exhaust, retract further into the head when closed because of the metal that gets worn away from those two areas. Thus the valve clearance shrinks, as the valve lifter is then pushed more towards the cam lobe/base circle.

 

The main source of clicking on the 3VZE engine is the fuel pressure regulator. Mine clicks like crazy.

 

Both you guys: Thanks. Shims are out w/o disturbing the cam. I fabbed a tool for collapsing the lifters. If I lived in Cuba I'd grind the shims - both scenarios would suck!

I tried before to post a "Thank You" but my learning curve on this site is still in its early stages. I gotta say though, this is one great site and I shoulda joined years ago. I'll be back......