[maxor]

Hello,

So for the past 2 months i've been hearing a rattle from the car when it was at idle and while driving. I figured it was a loose heat shield so I put it off for a while. Finally found some time and lifted the car on ramps and took off all the covers for inspection.

The sound seems to be coming from the torque converter, it sounds like marbles in a tin can and its very annoying.

Shifting doesn't seem to be an issue (right now) but i'd like to get the noise resolved. When at idle, the noise does go away somewhat, but comes back after a while. Driveability not an issue right now.

Can anyone tell me what it is or if my suspicions are correct.

[NinetyEight740]

That sounds horrible. Check and make sure bolts are tight to the flywheel to start.

[maxor]

Originally Posted by NinetyEight740

That sounds horrible. Check and make sure bolts are tight to the flywheel to start.

Yes it does.

Any way to check the bolts without taking the transmission off? It looks like you can stick a ratchet through the peep hole and reach some bolts and spin the torque converter with a bar, though i could be wrong.

Side note :

If i end up taking the transmission off, anything i should replace while its off? fluids, rear main seal, bolts, etc...

[NinetyEight740]

The bolts are accessible from the engine side. There is a plug in the oil pan you remove to gain access to them. You will need to be able to rotate engine over to find them one by one.

[maxor]

Was getting ready to take the transmission off and decided to pull the starter to inspect any play in the flywheel from there. Took out the starter and noticed some play in the pinon gear as it freely comes in and out without much effort. As well as the gears are very worn.

Will be ordering a new Bosch starter from fcpeuro hopefully it solves it.

[maxor]

Just checking back in... installed the new starter tonight and the car runs and sounds fine. The noise has disappeared and it sounds good as new. I’ll drive it for a bit and see if the issue comes back. Hopefully not. Issue seemed to be the starter gear. I’m thinking when the car was started, with the engine vibrations, the gear would slide back out and grind against the flywheel. I’ve inspected the flywheel teeth and everything looks fine there. Fingers crossed!

[Oembmw]

Originally Posted by maxor

Just checking back in... installed the new starter tonight and the car runs and sounds fine. The noise has disappeared and it sounds good as new. I’ll drive it for a bit and see if the issue comes back. Hopefully not. Issue seemed to be the starter gear. I’m thinking when the car was started, with the engine vibrations, the gear would slide back out and grind against the flywheel. I’ve inspected the flywheel teeth and everything looks fine there. Fingers crossed!

Having this exact same noise! been searching for months!

at least 10 technicians have driven and listened to the car.

all deemed it to be exhaust / heatshield. they tightened everything and nothing has fixed it.

Did replacing the starter fix it permanently?

Thank You

[E92_William]

Originally Posted by Oembmw

Having this exact same noise! been searching for months!

at least 10 technicians have driven and listened to the car.

all deemed it to be exhaust / heatshield. they tightened everything and nothing has fixed it.

Did replacing the starter fix it permanently?

Thank You

Well he hasn't been around since 2020 according to his profile so I guess he can't really respond but I'm sure if he went as far as updating what fixed it, he would have also updated a year later (this was in 2019 and he left in 2020) if it hadn't worked. Kind of makes sense it was this since it sounds like something is rubbing back and forth on the flywheels teeth

[BennettBucsFan]

That sound is a loose bolt that connects the flexplate to the flywheel. I know from experience. You need to check each bolt for proper torque and replace any that are missing. Filimng this was very dangerous as the bolt could have come flying out and hit you. I would not leave the car running when you are looking throught the transmission peephole.

[e90yyc]

Originally Posted by E92_William

Well he hasn't been around since 2020 according to his profile so I guess he can't really respond but I'm sure if he went as far as updating what fixed it, he would have also updated a year later (this was in 2019 and he left in 2020) if it hadn't worked. Kind of makes sense it was this since it sounds like something is rubbing back and forth on the flywheels teeth

Yup.

Originally Posted by BennettBucsFan

That sound is a loose bolt that connects the flexplate to the flywheel. I know from experience. You need to check each bolt for proper torque and replace any that are missing. Filimng this was very dangerous as the bolt could have come flying out and hit you. I would not leave the car running when you are looking throught the transmission peephole.

LOL. No it wasn’t. Did you happen to read the thread or just the original post?

[clairemc]

Yikes!

[Oembmw]

FIXED: Replaced my starter. 2007 335I n54 e90

I literally had the EXACT same noise in this video but it was very faint at idle youd have to be a nutcase to notice it (guilty)

for me, the noise would take place on acceleration from a slow speed or dead stop.

pulled the starter out and it had no logos or branding and it was also marked with paint. possibly a rebuilt BS part from previous owner / tech.

the starter started the car up fine. never had any starting issues. just the noise.

[clubs07]

I almost have identical noise coming from the same area under the car. Link posted below.
I checked the exhaust pipe and the brackets as well as the heatshield and all of them seem to be secured tight.
I am thinking of changing the starter to see if it is the culprit.
Side note: I changed my starter after it died with an aftermarket starter many years ago. It starts the engine just fine but could have the gear loose?
I also used a cheap endoscope to look at the gears from the peep window and the gears seems fine. I will also post a video of the gears.