E30 Zone

Do the M52 3l strokers suffer the same issue as the M54B30 where the oil pump gear comes off the pump shaft at high revs?

If not anyone know why not?

Is that a common problem for the M54b30 then?

I thought they had the wire lock setup on oil pumps.

But guess not with a quick search many weld (tac) the nut to the gear

Ive never welded a nut on, just loctite them and tighten them tight

The american lot report it regularly.

Never heard of it in the UK myself though.

I don't know if there is a usage difference there so your mileage may vary.

Apparently the sheering issue is to do with the harmonics of the pump, not to do with the tightness of the nut. Have seen a few high RPM builds on bimmerforums that have suffered it but they are 9k + rpm builds so wouldn't be worrying about it

Well this is it. The us boys report that the B30 cranks have bad harmonics but I have not seen any evidence to support this.

No reports of crank failures, flywheels or pully bolts backing out, odd bearing wear patterns etc.

I have seen all kinds of "reasons" for the harmonics from the cast vs forged, the stroke, the end pulley, etc.

It is only the oil pump that shows failures, nothing else in the system, which is a bit odd.

I was going to have a chat with a guy I know who designs cranks for a living. I am wondering if the dampers becoming weak and the nose of the crank whipping the chain and fatiguing the pump shaft.

Hence the question of if they still do it when put into an M50 or 52 using the M50/52 damper, pulleys, oil pump and chain guide.

If anything its more likely to do with the damper, it was a new design that came in with the E46 but before the 3.0 engine came about

Well that's what I wonder.

If there is no harmonic issue when everything is in good condition are the stock dampers failing due to the rubber in them going off.

A duff damper will cause harmonic issues at the nose.

The diesels are renowned for battering the dampers

API do a damper that is pretty popular in the US that's meant to be very good. It's also pretty pricey for what it is