So I've had a rumbling on start up when the temperature is around freezing. The colder, the louder and it rumbles for a longer distance. Usually it only last for about 10 or 20 feet. Seems like when in a turn and the weight is shifting to one side I'll get the rumble for a sec until the weight shifts back.

Today I climbed around the undercarriage and checked for a loose pipe or pretty much anything out of the ordinary. I knew I had a hole, a little bigger than quarter, in the bell housing. Today I noticed something laying on top of the transmission peep hole so I used a magnet to fish out the object. If that hole wasn't there, I would have never got it out.





I assume I'm missing a bolt to the torque converter and I need to pull the transmission now.........

 

It doesn't look fully formed so maybe one of the other bolts gave birth. The TC has studs and gets nuts, so maybe the front cover of the trans. Curious about the hole, aluminum bellhousings usually don't just rot out. The edges indicate it's not fresh.

 

Yeah TMT, not a fresh hole. It's been there since the time of purchase. Always great when you find crap AFTER purchase right. lol

I have no clue as to where the bolt came from. I think it's been there for awhile and is the root cause of ME replacing a starter or two this year. Also I believe it may be the cause of a slight vibration I've been nit-picking. It may have bent or warped something.

Anyone know where this might have come from internally?

 

Sir, you have no idea. Like $16,000 load of crap.

 

I'm thinking that's a rear cover bolt that came out and worked its way down between the rear cover and flywheel. IIRC, it'd be an M6 bolt with an 8mm head. Maybe it got chewed up by spinning stuff like the flywheel to make that groove.

This isn't the best pic of them, but what I could find quickly.




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That's a good possibility too.

 

On my cold 33* start up this morning I still had the growling noise after removing the bolt. I was hoping that the fly wheel or torque converter was rubbing the bolt causing the noise. I almost feel as if it's the hpop.