View Full Version : Hollow Clacking Sound Redux

10-01-2008, 06:38 PM
Ok, my buddy and I rebuilt the engine in my oldest son's SC after he over heated it and blew a head gasket. We installed new rod bearings, new rings, new lifters, new heads, all new gaskets, checked wrist pins, crank bearings, honed the cylinders. There was no wear or galding (sp) on the crank or the cam. Miced them all. The mains are solid as are the crank and cam bearings. We reassembled the engine, fired it up and there is a hollow clacking sound coming from it. And it is almost a phantom sound....we have not been able to pinpoint its exact location, the sound pitch changes with a change in vaccum, and at high rpms, say 3000+, it virtually disappears. We even tore it back down, double and triple checked everything and still the noise persists.

Needless to say we are at a loss. Plenty of power, runs smooth, etc.

So....HELP!!!!!!!! :)

10-01-2008, 06:42 PM
maybe a mechanics stethoscope might help you pinpoint the location of the noise.?. just throwin out ideas...i know they are used to find things like collapsed lifters or bent pushrods.......

10-01-2008, 06:46 PM
Are you sure the dip stick tube isn't hitting something? Seems like something that happens from time to time.

10-01-2008, 07:01 PM
Automatic transmission? Did you check the flexplate?

10-01-2008, 08:22 PM
i second the dipstick. sounds like a bad lifter till it breaks. take out the dipstick and cap the tube with a vacuum plug.

10-02-2008, 07:19 AM
Automatic transmission? Did you check the flexplate?

It is a manual tranny. And I will check the dip stick.


10-06-2008, 05:03 PM
take a large screwdriver and put the handle up to your ear. Put the tip on each of the injectors. Mine make alot of noise, that I couldn't track down until I tried this test. Number 4 ended up being the noise I couldn't find. Sort of a clacking noise.