[Netzke98]

Hey everyone,
I’m not sure if this is rod knock. The transmission is in park during the first video, there is a loud ticking/knocking. The second video has a spudder sound. The third video I disconnected the transmission from the engine. It’s a lot harder to hear any odd noise. When doing all this I also replaced the oil pan gasket & inspected the transmission pump. I didn’t find any of the bottom rod bearings to have play. I did replace the flex plate and torque converter but still had the same sounds.
Thanks for any help!



Bell housing knock
https://youtube.com/shorts/2P0ka9FVjQQ?feature=share

Acceleration noise
https://youtube.com/shorts/2ZTuICnkG-w?feature=share

Engine running with transmission disconnected
https://youtube.com/shorts/Ss56cGv1In8?feature=share

[SuperLomi]

Any debris/copper specs in the oil filter?

Have the old sent to blackstone labs for analysis.

[yupetc]

You can check your rod by opening up the spark plug port and use a long enough 3/8" extension to pass through the port and press against the pistons.

This is a quick one to learn from:
https://youtube.com/shorts/5y4Iy5aU6DA?feature=share

[Netzke98]

Thanks! I’m getting oil tested now. I tried that but I didn’t feel any movement

[F32Fleet]

Doesn't sound like rod bearings to me.

[F32Fleet]

Originally Posted by Netzke98

Thanks! I’m getting oil tested now. I tried that but I didn’t feel any movement

Oil UOA will probably not show signs of worn bearings. BMW stopped using lead before your car was built.

Just peak at your oil filter and housing. Look for glitter.

[SuperLomi]

Originally Posted by F32Fleet

Oil UOA will probably not show signs of worn bearings. BMW stopped using lead before your car was built.

Just peak at your oil filter and housing. Look for glitter.

It will show a high copper ppm.

[F32Fleet]

Originally Posted by SuperLomi

It will show a high copper ppm.

Or not.

[SuperLomi]

Originally Posted by F32Fleet

Or not.

Ah yes, you have convinced me with your eloquent rebuttal….


Care to actually explain what you are thinking, or post some form of source material?


I can’t imagine an oil analysis being less specific than looking for shinies in the oil filter. And form personal experience a spun bearing will shoot up the copper ppm beyond the normal 2-3ish.

[F32Fleet]

Originally Posted by SuperLomi

Ah yes, you have convinced me with your eloquent rebuttal….


Care to actually explain what you are thinking, or post some form of source material?


I can’t imagine an oil analysis being less specific than looking for shinies in the oil filter. And form personal experience a spun bearing will shoot up the copper ppm beyond the normal 2-3ish.

UOA's measure particles of a certain size. For example glitter won't show up. A spontaneous failure isn't likely to show up.

Basically a false negative is possible.

[SuperLomi]

Originally Posted by F32Fleet

UOA's measure particles of a certain size. For example glitter won't show up. A spontaneous failure isn't likely to show up.

Basically a false negative is possible.

I mean, yeah nothing like this is going to be 100%, but you’re describing an edge case situation.

Hardly supports the statement:

Oil UOA will probably not show signs of worn bearings.

So what info is making you form this opinion. Genuinely asking because I didn’t find anything with a few quick searches.

But I know I can find plenty of examples of oil analysis which did confirm a problem, my own included.

[F32Fleet]

Originally Posted by SuperLomi

So what info is making you form this opinion. Genuinely asking because I didn’t find anything with a few quick searches.

But I know I can find plenty of examples of oil analysis which did confirm a problem, my own included.

https://bobistheoilguy.com/forums/th...g-wear.200468/

https://bobistheoilguy.com/forums/th...g-wear.107183/


It's kinda of silly for the OP to pull a sample for a single-pass UOA without commenting on whether there's glitter in the filter.

[Netzke98]

Oil report came back

[F32Fleet]

Originally Posted by Netzke98

Oil report came back

You may want to mask your personal information on the UOA

[SithF30]

I have a similar noise, but only with warm engine and a lot less loud than yours.
I replaced the flex plate, torque converter, rod bearings (the old ones have been fine). All pulleys, belts and so on. No change unfortunately. Oil reports show no irregularities.

[Netzke98]

When my car is in drive on the lift the knocking turns to a intermintant rattling. I’m starting to think that it’s worn transmission bushings

Output shaft play
https://youtube.com/shorts/k-6LRbjP3...9X9p1HJaTP1vuH
Transmission rattle
https://youtube.com/shorts/17SMv6wJM...XYqlbhS6FSuzxU

[yupetc]

I can't help but agree with your suspicion. Is there a way the transmission can be diagnosed by a transmission shop quite easily without having to remove the tranny? I remember in your first post that you did have your transmission off the car and engine running. On that video, I find much less irregular rattling. With the latest videos, I hear more of a muffled irregular rattle. Anyway, very interested to know what's the final diagnosis, but if there's no more reason to suspect motor being the culprit, I'm in for more learning about the transmission if that turns out to be it.

[Netzke98]

the bell housing knock is when it’s in park. last video is when the transmission is in neutral. I ordered the rebuild manual off of eBay. Taking off the transfer case really is the only way but at that point you might as well drop the transmission. Took me 4 hours to drop trans

[yupetc]

Eager to find out the outcome, hopefully that noise can be fully addressed after the transmission replacement.

[Netzke98]

I got the transmission rebuild manual. Dm if you want a copy

[yupetc]

DM'd.

[yupetc]

By the way, did you get that possible transmission issued fully worked out? or are you in process of rebuilding it, seeing how you've obtained a full set of service manual.