MTFCA Forum

What am I looking at for parts if I determine I have a noisy wrist pin?

Do you know if your car has cast iron original pistons or does it have aluminum pistons.
The original style cast iron pistons have piston pin bushings that can be replaced.
They are still available.
The newer aluminum pistons don’t have piston pin bushings that I know of. Others might know different. Maybe replace the piston and piston pin if it’s an aluminum piston.

If you determined which piston the noise is coming from you’ll have to pull the head and engine pan and remove the rod/piston then you will find out if it’s a loose rod, piston pin ,loose wrist pin bolt or maybe a bushing if it’s got cast iron pistons. Maybe a broken ring would cause a clicking noise? Not sure on that one.

If you find your issue a new head gasket would be needed to put it back together with. Also maybe a pan gasket/sealant.

Thanks. Used a stethoscope today and really couldn't narrow down which cylinder.

Aluminum pistons 40 over. will pull the inspection plate tomorrow and get my hands dirty.

Sure would be nice if it was a rod cap...

Piston pins can be changed without removing the cylinder head. The rod/piston can be drawn down far enough that the pin can be removed just by taking off the bottom inspection plate. With cast iron pistons there is the complication of having to compress the bottom ring when pushing the piston back up the bore. With alloy pistons, no such complication.
I do wonder how the diagnosis made though.

Allan from down under.

You mentioned ‘if’ in your post. You mentioned your engine has aluminum pistons which could mean it’s been rebuilt? Does your engine have adjustable lifters? Maybe something in the camshaft bearings or lifters? The noise you can hear in these engines can fool you. Good luck in your checking it out.

If you take the rod out, it might be a good idea to check it's alignment to be sure it doesnt have a little twist or bend in it. I've heard they can be bent when tightening/loosening the wrist pin bolt.

Any time you are working with an old motor or Installing NEW rods they should be checked. The last guy may have twisted them installing pistons. New rods are frequently a bit twisted. The last re- rebuild had new rods with a little twist. Verify, verify.

The rods can be checked for bend and twist once you have them out. Still no need to pull the head, but probably easier if you don't have access to a hoist.

Allan from down under.