94 low miles - knocking sound turning off engine

[bstaneland]

The knocking sound after the engine shuts off. Very concerned.

Thoughts on what it may be?

Rod knock from 1st gen Viper???

youtube.com

 

[99RT10GTS]

If your oil pressure is good and you're not hearing it while running, I would move to the clutch, possible a loose flywheel pressure plate.

 

[Steve-Indy]

Maybe a stuck open injector that is causing dieseling ?

 

[bstaneland]

I don’t hear it while the engine is running (a good sign), but that may be because the exhaust I have is loud and drowns it out.
Going to get it in the air this weekend and see if I can figure it out.
I was thinking (hoping) motor mounts or some kind of a bracket or something loose with the clutch because it does have more of that kind of sound.
Not to mention I’ve never heard of the 1st and 2nd gen Vipers having internal issues.

 

[TEALLIFE]

Doesnt sound like knock. You should be able to hear it when running if you get in there close, if it was.

 

[fxchevyshop]

Doesnt sound like knock. You should be able to hear it when running if you get in there close, if it was.

Does it knock after engine switch is turnoff for few seconds?

 

[AZTVR]

It sounds like sheet metal. However; I would say that motor mount would be the number one suspect from those symptoms because it seems to have been a VERY COMMONLY reported failure in the past. The rubber ages out just like tires, except faster, I think, with the addition to 8 liters of engine heat. The next most suspect; at almost the same suspicion level would be a loose exhaust piping connection. I used "the best" clamps for the slip joints on my aftermarket High Flow Cats' outputs and one side, I could never get to stay tightly clamped until I spot welded it. Just one spot. (2002 GTS) Actually, it is likely to be a combination of both issues. Include the transmission mount as something to renew if you do motor mounts.

 

[daveg]

I would look at exhaust first, sounds like its hitting something.

 

[bstaneland]

You know when you want to kick your own *** for being dumb?
That’s me right now.
It was just the wing on one of the nuts on the exhaust ****** bolt that was just barely touching the chassis.
Apologies for wasting the time of those that commented.

 

[bstaneland]

“f l a n g e” is a word that gets blocked? Weird

 

[BlackWidow]

Really

Flange

Not anymore