Clicking noise: bad piston?

[forestdan7]

87 4Runner 22RE 5 speed

I've got a clicking noise that's been on and off for a while. Right now, if I hold it at 2000 RPM, it's loud and constant, but only very intermittent at idle, with no rhythm to it at idle. Above 2000 RPM, it's also intermittent.

Sounds like one of those old noise makers at football games. Very metallic sound. I used a hose tonight and could not locate it very specifically, but seems like it's coming from inside the block.

It's not from the timing chain I don't think, and the valves are kind of loud, but not like this.

It really sounds like it's one cylinder doing something bad. Any ideas? With the rust issues I've got, I'm not sure I'd be into rebuilding this engine.

 

[Hilux]

If its from the top, and a light clicking, I'd say piston slap.

Bottom, and more pronounced I'd say rods...

 

[forestdan7]

Thanks, Hilux.

It does sound like it's more from the top. But it is pretty pronounced.

It is strange that it's only around 2000 RPM, and not constant at any old speed.

I was about to drive a few hundred miles in her this weekend. Would either piston slap or rods leave me stranded, or is it just going to get worse and worse and start running bad?

 

[PressOn]

I picked up an 81 landcruiser (BJ42) in Tennesse and drove it to northern Michigan with a respectable piston slap. I put on another 4k miles until I got the rebuild parts together. In my case it was a cracked and missing piston skirt on half the piston. It also had a sweet spot where it was pronounced similar to what you describe.

I'd suggest pulling the oil pan and take a look. You might see where the slapping is coming from.

Good luck.

Jeff

 

[WristPin]

neither one of those possible problems are going to be nice to you.

if you are genuinely concerned about it, tear it down and fix it.

it also could be broken chain guides, and the noise is chain hitting timing cover.

use a stick as a stethoscope, not a hose. and check the timing cover for the noise

 

[forestdan7]

Good ideas. Thanks for the feedback. I'll post up what I find out. Might even let my mechanic take a listen this weekend if he's got the time.