Idle fixed, Knock not... But.....

[89SilverSHO]

Ok after buying new Bosch Platnum Plugs and Bosch Wires (besides for being alot lighter in the pants) has fixed my idle problem but not the knock. Seems when in nutral @1000rpm - 2750rpm its a knock BUT from 2.75k and up its a chatter. You can definately tell the difference from the idle sound and the high end sound. Im in the process of replacing all the vaccume lines now (old ones were beyond shot, crumbled in hands). So what could this problem be? Ive taken off my harmonic and looked at my timing sprocket it seems to be in good shape so i dont think crank cancer is the problem. Suggestions are welcomed since this is my only source of reliable accurate info

Thanks,
-John

 

[89SilverSHO]

Perfect way to describe the sound is by hitting a pen against ur desk and holding it from the bottom very hard sound. I also just checked my pullys and other misc. things for tightening. Sound seems to be coming from #2 cylinder using a scope to listen for it.

 

[sdpatt]

From the lower end of the engine? Connecting rod bearings. From the upper end? Badly worn valve shim.

Bosch plugs and wires? You'll need to replace these with the real parts for the SHO soon: Motorcraft AGSP32PP plugs and WR-4033 wires. These are NOT quality replacements for the SHO engine.

 

[89SilverSHO]

Valve shim... What does a badly worn one look like? Is it easy to replace? Ive looked at them when i did my CPS and Knock but didnt really inspect them closely. Think this has worn down my lobes?

How long you think i can get out of those plugs and wires? Ive herd mixed opinions about them throughout the board.

-John

 

[sdpatt]

A shim damaged badly engouh to cause the noise you are describing would most likely have damaged the cam lobe. There is no way to know until you check it out.

The Bosch plugs and wires? From a few thousand miles or until they decide to give up the ghost. They are not the correct components or properly fitted for the SHO application.

 

[89SilverSHO]

Thanks ALOT scott for the info looks like i have a new project on my hands... do you know where i would get the new shims?

-John