Strange Rattle

[Gunmetal Speedster]

Hey guys. So I recently had transmission work done (very long and annoying story so I wont get into it) but it required changing to a new transmission. Transmission seems to work fine, however, now when driving and idling I have this sort of, "rattle".

There are two different sounds that I'm hearing, at different times as well. Under acceleration and coasting at low speeds in neutral and in gear, I hear this deep rattling noise. When the car is stationary just idling the noise is there as well. It's not constant rattle, but it stops for a second and returns then stops and starts again. If I rev the car, after the revs die down it has a higher pitched rattle for a second and that goes away.

I know what I'm describing is very vague and not very descriptive, but that's all I can think of how to describe it. I'd post a video but it's very deep and I don't think it would be audible. Also, maybe I'm crazy, but it feels like I can "feel" my exhaust in my gas pedal more than I used to. I'm longtubes, cat deletes, and SW retro all the way back.

I believe you have to move part of the exhaust in order to drop the transmission right? I'm thinking maybe something is loose (even though I've pushed on it and it doesn't move) or maybe it's the heat shield? I don't know. If you guys have any questions or suggestions I'm all ears haha. I need to get under the car and start seeing if anything is loose I suppose

[LPcox628]

Check the heat shield under the car. Also check if the exhaust is sitting on the cost member on the passenger side. That has been what I have read or experienced.

[SquawkVFR]

Sounds like it has nothing to do with the transmission at all....

so begin with getting under the car and grabbing the exhaust at every point you can and shaking the hell out of it and tap around with a rubber mallet, including heat shields braces etc.

I'd betcha a dollar they simply didn't tighten something or didn't reassemble something or broke something (minor) when putting it all back together.

[SquawkVFR]

PS...Then the crawl under it while someone revs the motor diagnostic plan. Better you than you me.

[Gunmetal Speedster]

Sounds good fellas! I will give it a look and report back with my findings haha!

[Gunmetal Speedster]

Just to keep this updated in case anyone else ends of having the same issue, this is what I've found upon checking today. The light metallic high pitched noise I was hearing was due to a loose o2 sensor. Crazy how that makes that much racket but it does haha. As for the deep rumbling rattling going on, that's a whole other can of worms. Took it to my local shop and the master tech got it on a lift and everything and couldn't diagnose it from just listening and tapping around. I'll be dropping the car off with them next week and they will be opening her up to see what the cause is. They were thinking it had something to do with the flywheel? I dont know they are much more mechanically inclined than I. Hopefully all is well after this. I just want my pristine car back without having to deal with something every time I get in haha. Will continue to update this thread.

[ShadowYYZ]

Originally Posted by Gunmetal Speedster

Just to keep this updated in case anyone else ends of having the same issue, this is what I've found upon checking today. The light metallic high pitched noise I was hearing was due to a loose o2 sensor. Crazy how that makes that much racket but it does haha. As for the deep rumbling rattling going on, that's a whole other can of worms. Took it to my local shop and the master tech got it on a lift and everything and couldn't diagnose it from just listening and tapping around. I'll be dropping the car off with them next week and they will be opening her up to see what the cause is. They were thinking it had something to do with the flywheel? I dont know they are much more mechanically inclined than I. Hopefully all is well after this. I just want my pristine car back without having to deal with something every time I get in haha. Will continue to update this thread.

Keep us updated! I have a light mettallic sound over 88 MPH..
after 89 on 5th gear v6.. it goes away

[SquawkVFR]

Originally Posted by ShadowYYZ

Keep us updated! I have a light mettallic sound over 88 MPH..
after 89 on 5th gear v6.. it goes away

Consistently?

[ShadowYYZ]

Originally Posted by SquawkVFR

Consistently?

It goes away after climbing up even higher on the RPMS.

I tried replicating and it works at 3rd gear @ 65 mph RPMS bout 4K.. Sounds like its coming from the front/underneath...

Like a metallic swoosh sound.

loose heatshield/cat convert? perhaps :/?

[Gunmetal Speedster]

I have officially cleared my car of all noise now! The light metallic pinging was the o2 senors and the deep belowing grunge was the exhaust hitting the tunnel brace. Took the brace off and all is well. Strange how those little things can make such a worrisome sound. Glad it was a simple fix though!

Sorry about your current issue, I have no idea what might be causing it. Just make sure everything is tight and start there, Let me tell you, you would be surprised what something being slightly loose can cause