Noise in valve cover!!!!

[ViPER1313]

Might sound weird but I had a crazy knock coming from the valve covers / engine valley that I thought was a bad timing chain tensioner / bad fuel injector / sticking valve or badly worn valve shim. It was very intermittent, and normally only occurred at a warm idle. It would (usually) go away when revving the motor. After checking or replacing every one of the above items, I found out that it was a bad coil pack. I never knew that spark knock could be that loud, but whatever had failed inside the coil was causing severe pre-ignition (or something along those lines) that was making the motor sound like a diesel / it had thrown a valve shim.

Just thought I would share....

 

[frosho]

I never knew that spark knock could be that loud, but whatever had failed inside the coil was causing severe pre-ignition (or something along those lines) that was making the motor sound like a diesel / it had thrown a valve shim.

Just thought I would share....

Sounds like a shorted plug wire was arcing and resonating in the plug well.

 

[blown331stang]

Yes I get my stang mixed up with it, lol. It does appear to be coming from the timing chain cover.

 

[blown331stang]

I mean timing belt, you see.

 

[HotRodKid]

belts are on the passenger side, chains are on the driver side

 

[ViPER1313]

Sounds like a shorted plug wire was arcing and resonating in the plug well.

Nope.... plug wires were not changed, only the coil.

 

[green94mtx]

I'm also having a similar noise as explained with my 94 mtx. Coming DIRECTLY from the valve cover where the timing chain is. Thought it was valve lash but the plug wells have been dry for the 5k miles that i have owned the car. I just wanna be certain before i tear it apart. Here is a vid i took of the sound.

http://www.youtube.com/watch?v=35tobhQEPDY

 

[hawkeye18]

Way to necropost, but beyond that, that does indeed sound like a bad timing chain tensioner.

 

[green94mtx]

"Necropost"? And thanks, i'm going to start tear down in the spring. Checking lash clearances as long as i'm in there.

 

[hawkeye18]

"Necropost"? And thanks, i'm going to start tear down in the spring. Checking lash clearances as long as i'm in there.

The last post in this thread before yours was from almost a year and a half ago. You brought this thread back from the dead - thus, necroposting.

It's not really that big of a deal, I guess - just try not to get in the habit of it.

Good luck with the teardown!

 

[green94mtx]

Well everyone complains about posting threads without searching first... But yeah thanks!