MadaboutKitcars

If anyone is using an M54 or later engine with VANOS this could be quite interesting.

My daily driver, an E46, has an M54B22 and it's been a bit, well sluggish even for a 2.2. It also had stalling and rough idle issues. It runs on LPG so some I though some of it was that. However many of my issues fit the fairly common VANOS seal issue. It has 127k on the clock.

So at the weekend I changed my VANOS seals. Not too bad a job, it takes a while and is easier if the engine is out the car so worth doing if you're overhauling and engine (especially on a Z4, see later...)

BMW don't supply the seals, only whole units so there's a few sources of kits to do this repair one is http://www.beisansystems.com where I got mine, Richard got his from a UK source i6 on ebay.

There's a detailed document on how to change the seals here: http://www.beisansystems.com/procedures/vanos_procedure.htm

While changing the seals I also the rocker gaskets - the main large one, the two that go over the spark plug holes and one for every bolt that holds the rocker in place. Also needed a gasket for the vanos unit (this was in my set, but not the one Richard got from i6).

Got all the gaskest from BMW - was actually cheaper than from gsf - Richards 3ltr has a different part number for the rocker gasket.

Here's a few pics from mine:

My rocker gasket has gone hard and started to crumble so changing it was a good idea:



Here's the VANOS unit right in front of the cams:



You can see the LPG injector gubbins on top of the engine:



A view down the cylinder 1 spark plug hole - the gasket here was so solid it shattered while removing so you need to be fairly careful bits don't go where they shouldn't.



Cam still looks very good, like new almost



VANOS unit removed from front of engine, everything covered up to avoid dirt getting in there



The VANOS unit disassembled



I don't have any more images, had stuff to do an ended up a late night due to also doing Richard's Z4 which was a real PITA due to not being able to get the VANOS unit off the engine without shortening some of the studs that hold it on - there's a metal re-enforcement plate over the whole of the front of the car that's a pain to remove.

The seals are one the two pistons in the photo and consist of an inner o-ring and outer teflon ring. You need to carefully cut the old ones off, soak the new ones in warm water and fit. The telfon outer rings deform when you put them on so I used a tiny screw driver to run all the way round them and straighten them out.

I've only put 80 or so miles on it so far. I've got noticeably more torque below 3000rpm much smoother driving from a standstill and cruising. In theory I should see an improvement in consumption but it's too early to say yet.

I just did this on my ~128K M54B25 engined E46 today. All in including a new vanos gasket from BMW it cost £30 so not bad. I did the horrifyingly brittle rocker cover gasket about 15K ago and when I took the cover of today it was already showing some stiffness over a new one so they don't last long. It took me about 5 hours what with all the cleaning of the VANOS components. Mine's an auto too which means wrestling with the viscous fan and removing the rad top hose etc to get at it. I also bought my new seals from i6 on ebay. It was a nice little package which also included new bolts for the piston covers and some instant gasket for resealing the cam cover.

I'm not 100% yet on a difference (only done 8 miles mind) but I have noticed that in 5th it now picks up much better from about 40mph where as before my engine revs would rise a bit and no acceleration what so ever. in lower gears with more spirited driving I see no difference but that would make sense. At higher revs and lower gears the high oil pressure the seals would still hold back enough oil to actuate the piston anyway but I can imagine at lower revs and hence lower pressure that the oil would just sneak past. I suspect the main benefit I'll see is improved mileage.

Your engine has obviously been well looked after with frequent oil changes as it looks almost new inside. Mine is covered in baked on blackness so the previous owner(s) obviously believed the 20K oil change interval nonsense that manufacturers claim these days.

It does take a little while for everything to settle in after the change, but the additional torque is noticeable fairly quickly.

Mines had the oil changed at every required service interval, so 15k or less depending on what the computer recorded. It has always been run on BMW long life compliant oil LL02 previously and now LL04 It just ticked over 130k this week!

For the last 60k ish its been running on LPG which I've been told burns cleaner, I don't know if that would have much effect on the oil itself though.