MRPVette

84 4+3

My guesses as they came to my head:
1. Knock
2. Flexplate cracked
3. Loose torque converter bolts if auto
4. Exhaust hangers
5. Bad cat
6. Heat shield

Shut off the car, let it cool and start banging on crap seeing if you can get it to make noise with out the engine running.

billschroeder5842

I'm going with something exhaust related. And as above, I'm going to guess heat shields. Those come loose after time.

MRPVette

I was hoping it was exhaust related banged around a bit with rubber mallet but didn't hear anything I am leaning towards Loose torque converter bolts,I haven't had it up on ramps yet how difficult is removing the fly wheel cover on a 95?Thanks Mike

Paul Workman

It sounds like thin metal of some sort that is definitely related to changes in RPM. It sounds like heat shields or perhaps a catalytic converter (guts) is disintegrating?

I've never experienced loose bolts on the torque converter, but I would think one would probably actually feel more of a clunk when shifting out of neutral or at the point of taking your foot off the throttle to coast to a stop. If I had to wager on it, I'd bet against the torque converter bolts: too "tinny" sounding (to me).

Ya need to get it up in the air when it is running to do more diagnosing. (I have done such on jack stands, but don't recommend it, even with hydraulic jacks positioned on the frame as a safety measure: Schitt happens!)

xrav22

Oh that sound is just like my TQ Converter bolts when they came loose.

MRPVette

Dam that top flywheel cover bolt on the passenger side was a pita to get off after finally getting it unbolted looks like I still need to take the starter off to get it out of the way to inspect the flywheel.

MRPVette

Got the fly wheel cover off and it is definitely louder all the flywheel bolts seem to be tight so I am leaning towards the torque converter,do these things come apart inside? don't know how to confirm the converter for sure.

dclong

I had a similar noise coming from under my 86. I was convinced it was flex plate at first, but after more looking/listening, determined it was the right front ?resonator? /catalytic converter. I guess that's fairly common that the baffles or internals come loose and rattle inside those things. I figured it out by using a short piece of heater hose as a stethoscope. I could hear that it was definitely coming from the front resonator whenever I moved the end of the hose close to it.

I replaced the y-pipe , resonators/cat. problem solved.

Can't say for sure that the sound on your video is the same as mine, but I'd suggest using the hose-stethoscope to listen and pinpoint the location of the noise first before doing anything.

MRPVette

OK Haven't had a lot of time lately but look one of those mechanic stethoscopes to it and it seemed loudest from the left front exhaust,I also noticed this in my drivers side exhaust so I leaning toward mt left front catalytic converter.

MRPVette

Can't get pic to load.

MRPVette

So close but yet so far,Can't get these studs off to save my life any ideas?

Ed Ramberger

Hard to diagnose like this but sounds like a convertor breaking up to me.

If you want to remove the stud, heat the flange. If you can't get a grip on the stud, double nut it - lock two nuts against each other and they become locked onto the stud. then a 12 point socket can be used to back it off.

MRPVette

Man that was a lot harder to get off than I expected but its off.

MRPVette

Finally got it out

MRPVette

Definitely coming apart

Ed Ramberger

Thank you for following up.

MRPVette

So are there no gaskets that go on the front and back of the converter?

1993C4LT1

That I don't know. But nice to see that the converter is coming apart.

Ed Ramberger

No - the ball/tapers seal