Putting this here because it becomes an issue as the kms rise so I guess "future restorers" and those with engines of unclear provenance might get the most use from it. Hopefully turns up in searches easily enough.

If you have a LuK vacuum pump P/n 06D145100- be very careful of the revision number when ordering the external seal:

Pump. Seal.
06D145100E. 06D145117 (note no revision number)
06D145100anythingelse. 06D145117A

The two seals are completely different sizes. NOREV is 53x2, while Rev A is 56x2.5. A lot of online sellers (eg Vagparts) only have the Rev A and list it as applicable to all EA113 engines &or all vacuum pump revisions. It isn't, and it took me a long time to find out (2 incorrect parts, from 2 different sources).

Of course if I'd been sensible and checked ETKA properly first this wouldn't have happened but Nemigaparts' version is so painful to use coming from RealOEM for beemers I got lazy and paid the price (which was $80 worth of useless parts and 2 weeks downtime...)

Don't do what ProfessorDon't did, eh?

Vacuum pump woes-img_20220511_093614_hdr-jpg
Lefty is correct, righty is No Good for my Rev E pump...