Did BMW change the valve stem seals during the build years of the N62?
 

Only reason I ask is that the dreaded blue smoke on idle issue appears to be more common on the earlier years particularly the '04s. TIA

Id say no considering alot of 4.8 have it..

Im at 77.5k 06 got it like 65k, buddies is 06 at 145k has it too..

Im glad that kit came out though, ill be doing them myself sometime early 2014.

Is yours smoking? Is the root cause lack of oil changes or faulty seals?

What kit???

Got it!

https://www.agacoolantpipe.com/produ...stem-seal-tool

Id say PO oil change intervals... Most likely followed bmw dumb intervals... Other buddy has 107k and even runs thinner 5-20 and no smoke. Also 06.

How would OE oil change intervals have anything to do with valve stem seals? Are the valve guides trashed (meaning it isn't a valve seal problem) or are the rings shot? Both of those are at least related to lubrication. But given the number of vehicles exhibiting valve seal issues, both seem unlikely.

JCL, my thinking was that well used, dirty oil might contribute to faster seal breakdown and allow seepage. Just guessing however. Do you know if there was any seal update for the valves?

I don't know if they were changed. This thread notes that the colour changed to signify the new version, but you should confirm that on realoem with part numbers.

http://www.xoutpost.com/bmw-sav-foru...your-cost.html

Valve stem seals are not new technology. In my experience from other engines, the problem would likely be seal composition (hardening with age) or oil pooling on top of them. The problem is worse with worn guides as the valve stem moves and loosens the seal, but the fixes reported don't talk about guide replacement so I would suspect they are fine in most cases.

I haven't done a BMW but I have replaced seals on a Ford V8 I owned by making a tool up. I used shop air through a fitting in the spark plug hole to hold the valves in place and changed seals without removing the heads. That appears to be what people are starting to do on this engine now.

I think the whole oil change interval discussion is nothing to do with it.