Hello guys.
I had an issue with my mini r56 S (2008). It had rough idle and oil was leaking from turbo supply line. Well, i've done the job with all new parts according to many DIY videos/manuals (new timing chain kit and new oil feed line). I was ready to finish all the stuff, when I noticed that crankshaft seal (new one) is leaking. Yes, without even trying to crank the engine. I simply lubricated new chain and it's guides with half a quart of oil when the head gasket was off, and after manual rotations to finish the timing job, I noticed that seal is leaking.

First I thought that it's a bad installation of a seal in term of depth (I didn't install new pulley hub), so I tried to push the seal more without removing all the stuff. It wouldn't stop leaking. Then, I noticed that the pulley hub is actually NOT CENTERED relatively to seal housing... Well, I am a bit upset and confused. No manuals were talking about centering the hub with the seal housing..

The only thing I didn't do according to the manual - I've tightened crankshaft bolt without special tool. I was only relying on flywheel locker and applied a bit of counter-force to the vibration pulley when tightening.

I don't believe I could damage the crankshaft, so, what do you guys think could go wrong? Is there any techniques to put the pulley hub into correct position? I rotated the crankshaft externally and my pulley hub is definitely moving 1 or 2 mm up and down, which makes the seal pressed inequality around the hub, which lead to oil leak. And once again, all of this is just by rotating the engine manually. I was lucky enough (well..) to notice the issue before I put my radiator back from maintenance positions.

Any help is highly appreciated.

Pic of a new seal installed and leaking:

 

Double post, answered in your other one

 

Seems that your seal is twisted (looks like on the bottom seal seats deeper in the block than on the top) also my hub was rusted on the contact surface so buffed it out. Also hub might be twisted if you are not fully slided it into oil pump sprocket. Double check everything!

 

TimBaleia, not, it wasn't twisted. The picture is taken from some angle, and shadows are in play. However, you may notice on the picture above an OPENING of 1/3 of mm between pulley hub and seal's lip. It looks like its a part of dirt covering the pulley, but in fact its a hole. You may even see some internals through it


Guys, anyone got bentley manual? I am not sure if I installed the pulley hub correctly. I removed it today, and reinstalled, but I still have a feeling it's not centered (much less now, and not leaking), and also I think it's not sitting deep enough. Can anyone tell me some measure to make sure it's well installed?

The problem was that pulley didn't go deep enough into the oil pump sprocket, so it had some way to get off the center of the seal.

Below you will find some pics before I removed it once again. As you may see, distance between bolt's sides are unequal to the body of the pulley. I didn't take pictures after reinstall, but you couldn't notice anything from it. I measured all kind of distances between pulley hub and seal housing, between bolt and pulley body, and there's still some variance :(

Another observation - I couldn't decouple pulley hub and timing chain sprocket. Pulley hub seems to be a bit WIDER at the end. Wonder how did it get damaged.. it doesn't feel to be a one-time install part.

Anyways, I've ordered another bolts, pulley and seal to make sure I install stuff correctly. Hope that will solve the issue.
Tomorrow I will attach the external pulley and measure if it has some horizontal misbalance. I will attach some strong wire to the body of car, and set it the way so it just "touched" the pulley and then rotate the engine manually and watch if distance between pulley surface and my wire is changing. If not... well, I am not sure what am I going to do. May be I will remove sparks and rotate engine with starter to see if pulleys are shaking, just to confirm a bad install.

For anyone doing this job themselves - DO NOT TENSION the chain when tightening the crankshaft bolt. It will do it's best to get out of the axis it should be rotating along.

 

I wouldn't rotate engine with strter just to confirm bad install )

i will take a look in all manuals this evening to see what info provided there about hub.

Personally never had issues with it.

By what you are saying your hub is damaged. I should slide out of the block pretty easy with some WD-40 and timing chain bottom sprocket should stay in the block hanging on the chain.
i would suggest you to remove hub and first inspect seal. And how its installed.
Than inspect the hub and measure it with calipers to see if there is any "damage"/"mushrooming" to it.

i think what's happened in your case is that you installed hub not all the way in (may be because its damaged) and it was off axis lil bit and you tightened it with bolt thats why you have this up and down/side to side move.

Ill post specs today. Keep us updated!

 

The pictures above are taken before I reassembled the hub. Now it looks good, and even when you rotate the engine you can't notice any dis-balance. However, if you measure distances toward the seal housing, there's still eccentric. I believe the hub is mushroomed a bit... Not sure how could it happen, the torque applied is way to low to bend this type of metal. And if it IS mushroomed, then something behind it should also had smashed. All chains look ok, and all sprockets too.

The seal is new, and now it's installed correctly. Not leaking by manual turn of an engine, but you never know with these spring-less seals.

Today I will remove timing lower sprocket and try to see if hub aligns with the crankshaft surface. But once again, I don't know what would be acceptable eccentric, if any. Surface-to-surface of such limited area will never guarantee absolute alignment, unless machined very precisely, which doesn't look to be a case (with the hub at least). Also I believe the hub never touches the crankshaft. Otherwise it would be absolutely impossible to maintain required level of tension between hub and two sprockets (timing and oil pump). Having said this... I am lost.

Anyone knows how to make sure that oil chain is actually sitting on the oil pump side sprocket? I can't see it from the hub place.

 

I believe the 'hub' should come away from the timing sprocket and not wedged in and be stuck to it. Are you able to double check your sprocket is correct, did it come with a kit or did you source it separately? If the sprocket is the wrong size, then your hub will never seat properly as it will not go in far enough, even a mm would give the hub free movement when torqueing it up. You really are having no luck.

 

Timing sprocket came with a kit (from BMW/mini). It's moving on the hub very easily, but if you try to take it out, it will eventually get stuck at the top position. Making me think that hub is damaged. I didn't have an issue putting it (the only thing is that both part should be dry, otherwise it won't go in) on the hub during initial install thou.

Anyways, I've ordered new hub and sprocket, to make sure all is good. Now curious if I also need to replace the oil pump chain sprocket to be on a safe side.

About the luck, well, **** happens. I will anyways finish the stuff, but honestly - design is quite weird If camshaft sprockets are anyways tension locked, why wouldn't BMW make the lower one pinned?

Thanks for help.

 

Here is whati got.

A - timong chain and sprocket
B - oil pump chain and sprocket

 

Thanks a lot. obviously, there's no chain tension during crankshaft bolt torquing. Obviously I have put the hub in a position when it stuck in second (oil pump) sprocket, which caused it to get a bit mushroomed. Waiting for new parts, will assemble all first outside to make sure hub goes well through both sprockets, and will check if oil pump sprocket fits well on the crankshaft. Only then will tighten it to very low torque just to check the alignment.

What confirms my conclusion - I simply could NOT take the hub out of timing sprocket. It rotates very well at the final position on the hub, however, once I try to pull it out, it will get stuck. And I could see that hub is wider at it's end point, preventing the sprocket from getting off. Same damage prevents it from getting into second sprocket, causing misalignment.

Will report back with pictures of damaged units and caution for all the DIY guys

 

Ok, finally I've received all required parts. I took the pulley apart with both sprockets. In a picture and video below you can see what the issue was:






And now new pulley assembly:


Be careful installing this part.

 

 

Sorry for that. Yeah, the reason is clear. I didn't put the hub till the end into second sprocket, so it had some angle towards it. Once bolt is applied, the angle forces the metal to deform. Melting is probably because "mushrooming" is deep enough to touch the first sprocket too.

The shop didn't put the hub in the second sprocket AT ALL. As you can see, the full surface is widened, which means it was just put on the sprocket. They did apply a lot of torque, otherwise timing would mess up immediately. That's in fact what held the pulley hub. Once chain pulled a bit the second sprocket, engine faulted.