Since someone woke this thread up. My VC was removed for the first time ever at around 163,000km to retrofit/update a seal in the variable valve timing.
This is a 4/98 BMW 528i with M52 engine. I've had it since around 50,000km in 2001. It ran 5k OCIs with Pennzoil 5W50 synth before I owned it (original owner was a good personal friend of my indy at the time). I ran M1 0W40 on ~7000km OCIs for the next couple of years after that (the focus being on changing twice a year - before and after winter, not so much the mileage on the OCI). The last 4 years or so I've been using GC at 8,000km OCIs (again, focus on pre/post winter season). It was ARXed in 2006 with XD3 15W40, but on the shorter schedule. I was adding LC20 for 2007. This summer I'm running XD3 15W40 again, partially because I knew I was going to lose a bunch of oil when doing this job, partially because the price of GC spiked around here, and partially because I know the car likes it and it's summer.
The intake cames on this engine have a plastic cover, but I forgot to shoot any good pictures after removing this cover. This cover contains oil spray so the area of the VC above this cover has some classic Castrol soft red fudge on it. This is strictly vapour deposition and condensation and the spooge wipes off.
With my use of quality oils I'm a little surprised that I have the bit of staining and hard varnish. Even brake cleaner had trouble making a dent in it in some test spots. I would have thought ARX, LC20 and M1 would have had it bare metal. It's not a problem - just saying...
I also noticed that there's more staining at the rear of the head than the front. I wasn't previously aware of any oil flow characteristic to explain this in this engine. I'm checking into that.
Gallery of all photos:
click here. Best viewed full screen, pictures are 800 pixels on long side.
Overall shot:
Cam shot:
Some greater staining in areas of low flow:
Sprockets:
Cam cover spooge away from oil flow:
Certain lighting angles show the cam wear: