Darien

I’ve recently noticed a strange rattle noise under my 89 Shark! At this time it’s intermittent so troubleshooting is tough… although it sounds like it’s coming from the exhaust pipes or maybe above in the TT.

I’m hoping everyone can view the below “Dropbox” link. Sound familiar??https://www.dropbox.com/s/ooyv6zqyqh...%20PM.mov?dl=0

Mrmerlin

if you recently removed the sampling tubes from the manifolds and replaced them with plugs see if the plugs are loose ,
I have found this issue on 4 cars . hold your hand over the port to feel for gas escaping.
OTHERwise your TT bearings are ready to be replaced.
Send the TT to Constantine for upgraded bearings.


I listened/ watched the video

Landseer

Another possible source.

On 86 automatic I've had a metal on metal squall, intermittent and worsening. There is a spacer in vicinity of, in between, the snap rings that retain the TC shaft bearings. Somehow it started contacting and spinning with shaft. I used mechanics stethoscope to narrow down location. I ended up removing it, as it's only purpose seemed to be to as a pressing spacer. Solved, works great.

Darien

Thanks gents. The intermittent nature of this sound is frustrating… more to follow once I find it.

Please confirm if you could view the vid?

Petza914

with the car not running, bang on the exhaust with your hand or a mallet and see if you can hear it. Almost sounds like a piece of metal is inside the exhaust. Does your car have catalytic converters - a piece of the cat material may have broken off and is rattling around inside one of the pipes.

Darien

No cats but new exhaust installed just before rendezvous trip. I’m going out to use a rubber mallet and check the intake/exhaust test tubes.

Darien

Stan…your insight was spot on!’

I broke out my trusty stethoscope and waited for the noise to start, I started at the middle of the exhaust and moved forward. The sound was being derived from the driver side exhaust manifold! Checked the port and a PO used a flat headed screw and cap to plug the port. That screw was bouncing around inside the cap and resonating is down the exhaust!

Another easy fix in the books. Now I need some recommendations to securely plug that port.

Thanks Stan

Mrmerlin

OK that makes 5 cars with the improper repair,
check the right side port as well.
Find ball bearing ,
or use a short threaded cap screw that will sit proud of the port,
and the cap nut will hold it firmly in place ,
use antiseize. so it doesnt rust in place

Landseer

Dang, that was a great call, Stan!

Constantine

Nice call on the problem Stan.

This saved the OP hours of diagnostics and potential money fixing/replacing un-needed items.

Yep, Stan is a great resource to this forum.