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Well... I found the exhaust rattle... Now I'm paranoid
When I took the car out last weekend there was a very loud rattle from the exhaust. So loud that I turned around and took the other car.
I determined that it was coming from the Cat. I've never really trusted the Cat... it's the one Lindsay packaged with their 3" muffler set and it's always been a bit stinky. So I ordered a new one from Magnaflow.
Fast forward to this morning when I took the old one off (I love the new Quickjack... but that's a different story). The rattle came from a bolt trapped on the engine side of the Cat. Pictures are below.
The bolt is a bit rusty... but not at all chewed up. I've got to assume I dropped it into the system at some point when things were apart. The question is _where_. I don't see how this could possibly have come through the engine without, at a minimum, grenading the hot side of the turbo. Can't see how the wastegate could possibly be the source. The car running fine. I'd like to assume that it's just been sitting there... but the "baffle" on the cat that has been pushed in isn't making me feel any better. I'm not sure if that damage is related... It looks like the fiberous stuff between the baffle and the wall of the cat has given way. I don't see any real damage. I'm guessing the lighter rusty part on the bottom is where the bolt has been sitting. There wasn't any other "debris" from damaged... whatever.
Anyone want to make me feel better and say "you're fine... just put on the new Cat?" Or should I at minimum try to take a look at the blades on the hot side of the turbo?
Well... not without completely destroying it (and severely damaging the bolt). Not to mention whatever was upstream. I would think I would have noticed that...
Like I said... paranoid...
Last edited by Millermatic; 10-29-2022 at 12:55 PM.
Were it me, I'd chalk it up to a good story and get on with life.
If it's easy to inspect the turbo then I guess it's worth it for peace of mind (and I get it, I can be a bit neurotic about the cars, too!) but I think you're fine. I don't see how it could come through the turbo and still look like that and have the car still drive fine.
I also think you're probably fine. If the blades on the turbo were damaged in any significant way, I'm pretty sure you'd feel it in driveability and response. It sounds like, separate from the noise, you've been pretty satisfied (meaning, it's performing as normal) with the engine performance so chances are high you're all good.
It just could be that somehow the bolt got in there during the manufacturing process/and/or. Installation of the cat. OR some tech might have done it as a prank just to mess with your head. LOL!
Yes, they are usually found in the compressor vanes, making magic sparkledust. The bolt doesn't look right either, but it's a place to start if someone is worried about this sort of thing.
It just could be that somehow the bolt got in there during the manufacturing process/and/or. Installation of the cat. OR some tech might have done it as a prank just to mess with your head. LOL!
I'd love to think this... but I'm the one who put on the cat in question. And the exhaust. And turbo, wastegate, cross-over, manifold, head... Everything but the block.
Short story... unless that bolt was there since getting the cat from Lindsey... it's my fault it's there.
Here's my new theory: The bolt was just hanging out and not making any noise - and has been sitting mostly happily for the last year and a half. The internal baffle on the cat broke free last weekend - and _that's_ what was making the noise. That's not to say it came that way... just that it's been there at least since I last had the exhaust opened up.
Last edited by Millermatic; 10-30-2022 at 11:10 PM.
That bolt hasn't been through the compressor or the engine or it would be severely damaged. Other than a little carbon and light rust, it is in pristine condition!
It really doesn't seem to have been inside of the cat for long, as it is still pretty clean .
That bolt hasn't been through the compressor or the engine or it would be severely damaged. Other than a little carbon and light rust, it is in pristine condition!
It really doesn't seem to have been inside of the cat for long, as it is still pretty clean .
You’re right. The Cat is (was) only 2.5 years old. I’ve had the exhaust off once in that time (when I did the TT, transaxle and clutch). I must have dropped something.
As everyone has pointed out... there is _no_ damage and just some mild corrosion on the bolt. I just put the new Cat on and will put on the band clamps and exhaust sealant in the next day or so.
I did get to break out the MIG welder and try welding SS for the first time (had to extend the new Cat). Not the prettiest welds... but not horrible given that I’m out of practice and new to SS. And I have more confidence in the welds than those band clamps. I debated ditching a couple of the clamps and welding more of the tubing... but the clamps work and I’ve never welded galvanized, either.
While working on my '84 ZX yesterday, I came across one nut, a bolt (different) and 25 cents. I like to think all of this as being Christmas-like. I'm guessing I have the previous owner to thank but who knows for sure.
I've also found a variety of tools under the hood (and elsewhere) in other used cars I've bought over the years. I'm guessing they were dropped and impossible (?) to find at the time. Screw drivers have turned up in orders from used-parts sellers as well. (Hopefully there's nothing subliminal about that..!)
10-29-2022, 12:34 PM
Well... I found the exhaust rattle... Now I'm paranoid
