e30 m50, zf gearbox weird noise

[thisismatuuu]

Hey guys, so today i swapped my m50b20 nv for a m50b25 non vanos. im using a zf gearbox, single mass flywheel and a 228mm clutch. Now im getting weird noises at idle. Noise occurs when im not pressing the clutch and when the clutch reaches bottom. No noise when clutch pedal is in the middle. Small test clip too, at first i panicked thinking it was engine that was making the noise, but when clutch was pushed half way the sound went away. Oh and also car didnt do that before, but now when swapping the engine i also installed a brand new clutch disc.

[BristolE30]

Hey guys, so today i swapped my m50b20 nv for a m50b25 non vanos. im using a zf gearbox, single mass flywheel and a 228mm clutch. Now im getting weird noises at idle. Noise occurs when im not pressing the clutch and when the clutch reaches bottom. No noise when clutch pedal is in the middle. Small test clip too, at first i panicked thinking it was engine that was making the noise, but when clutch was pushed half way the sound went away. Oh and also car didnt do that before, but now when swapping the engine i also installed a brand new clutch disc.

I’m not sure with a ZF gearbox, but my Getrag 260 rattles at idle. It’s called the Getrag rattle, over time the innards wear and chatter next to each. As soon as you press clutch in goes away. Apparently it’s quite normal, maybe applies to yours also?

[flybynite]

Single mass flywheels always chatter compared to the Dual mass flywheels, however that does sound more like something is grinding slipping as opposed to the usual smf chatter

[thisismatuuu]

Thanks for the replies. the car didnt have that problem 2 days ago with the old m50 engine. Today i tried a different flywheel and clutch, still the same. Car runs fine about a minute and then the noise comes and starts increasing. Also as it turns out the crankshaft has a little longitudinal play that can be felt by hand.

[DanThe]

Check the 6 bolts holding the front pulley onto the crank, they could be too long

[Brianmoooore]

Is the new engine from an auto?

[thisismatuuu]

Yes

[Brianmoooore]

Yes

Did you fit a spigot bearing of the correct size in the end of the crankshaft?

[thisismatuuu]

Yes, zf gearbox uses the one with 15mm inner diameter.

[Brianmoooore]

Yes, zf gearbox uses the one with 15mm inner diameter.

That's my idea dead then!
Have you checked out DanThe's suggestion? Could be this or similar, especially if the crank's floating around.

[thisismatuuu]

Haven't had the chance yet but I doubt that. With my old engine I once used 1 too long bolt, u even can't turn the engine around with a spanner when these bolts hit something. Luckily I discovered it when turning the engine around with a wrench. What I dont get is why the engine is silent for the first minute.

[thisismatuuu]

okay so i figured someone in the future might come here searching for the same thing, so here it goes. all of my headache was caused by 6 bolts that hold the trigger wheel in place. The engine i bought came from an e34 which had AC, so obviously it had one extra wheel to run the ac so the bolts were longer. Now i just need to replace the crank seal that was broken because of these bolts and should be good to go. Shorter bolt for comparison came from my old m50.

[Brianmoooore]

This is exactly the scenario that DanThe was suggesting.

[thisismatuuu]

I had the same problem with last engine but then the engine didn't turn at all