Blue smoke on extended idle. 2006 4.8is.

[bcredliner]

I don't contend the bad valve seals are a safety issue but I do think the valve seals going bad at around the same time for the majority of any engine design is a poor design. I will accept I went to far saying it should be done for free. I agree we have had the engine for many years and lots of miles of wear. I don't think valve seals should last forever but since they are a consistent failure issue we should at least have an new design to replace the existing design when the seals go bad. It is a weak link. There are other seals and gaskets that often fail before 100,000 miles that should have been redesigned by now ,that, in my opinion, should still be good when the X is parted out. I have never had a Yugo but lots of other lessor 'quality' and lower priced brands that did not have problems like I read so often here. If they did they were far less costly to fix or much easier to DIY. New engine designs are obviously a higher risk for problems but over a period years I expect the engine is discontinued if still having problems like this engine or becomes far closer to bulletproof. A premier brand addresses cryonic problems of a vehicle. Nothing new here and I love my X but it has made me skeptical of their products and leaning more and more away from another purchase. And, I have had better luck than the majority of X owners.

[TerminatorX5]

[JCL]

Lots of talk about seals failing, but not much about valve guides. The usual failure mode for valve stem seals (not just on BMWs) is that the guides wear, then the valves have some relative motion side to side, then the seals (which are like a little donut around the valve stem) wear on the circumference, causing leaks down the valve stem. Seals can also go hard with heat over time and fail due to that, but the real question when replacing valve stem seals is whether the guides need repairing. If they do, just replacing the seals is a short term fix. Owners that plan to keep the vehicle should consider doing guides as well, or at least check them.

Next decision is whether to take the heads off or not. You have to in order to do guides. However, it is possible to replace only stem seals with the heads in place. Last time I did that (on a Ford V8) I drilled out a spark plug, attached an air line, and used shop air pressure via the modified spark plug to keep the valves seated (lifted) while I undid the keepers, removed the valve spring, replaced the seal, reinstalled the spring and keeper, and then repeated for each valve. I only had 16 to do, there are 32 here. It takes time, but isnt particularly difficult. Taking the heads off is more difficult, just because it is more complex.

[pcb5]

Getting the timing right is my biggest concern. I've dealt with plenty of single cam V8's but not an overhead cam. I guess you would need to mark the cam gear and timing chain before removing....then you would be able to reinstall to its original location.

[BigBlack48is]

Originally Posted by pcb5

Getting the timing right is my biggest concern. I've dealt with plenty of single cam V8's but not an overhead cam. I guess you would need to mark the cam gear and timing chain before removing....then you would be able to reinstall to its original location.

It's good German engineering... taking it apart and putting it back together will be a piece of cake and timing it is no big deal, the gears / chains are marked or you can always mark them again ( I would ) and you can always buy the cam lockout tool set to get it all done a little easier

My opinion on it at this time is to wait until the timing chain guides need attention and deal with the whole mess at that time. I am only using a qt. of oil every 5k miles, so it's not the end of the world.

Just an embarrassment at places like the drive-thru, stop lights and any traffic jam or extended idle situation

[TerminatorX5]

i just came across this thread (http://www.xoutpost.com/bmw-sav-foru...christmas.html)...

i wonder, should one go for the valve seals, can that job be combined with this collabsible tube job? get two things resolved in one shot...

and i haven't seen much info on N62 chain guides, that was plaqueing the M62 engine - would it be feasible to consider the chain guides replacement at the same time?

obviously there is an aftermarket modified coolant pipe for the leak...
there is NO factory or aftermarket modification for the valve seals...

Is there anything for the chain guides?

what else should be considered a ticking time bomb that can be addressed once the open heart surgery commences??

[BigBlack48is]

So after changing over to 5w40 oil and still seeing the dreaded blue smoke while sitting in a traffic jam yesterday, I continued to research the problem and I see it's not just a N62 thing. Some of the other guys have installed catch cans inline with their CCV / PCV system and have not see any smoke since then.

That in conjunction with the fact that after reading multiple posts of people stating that after they did plugs on their N62, all the plugs appeared to be the same color. This leads me to believe that the smoke is absolutely caused by oil being introduced into the intake via the CCV / PCV path.

So my next question is... has anyone tried to install a catch can on their N62 or are there any people out there with a N62 that has the OSV installed ( same basic principal as catch can ) and are they having any indications of the blue smoke at idle?

Just some food for thought

[TerminatorX5]

you lost me after the words "catch can"...

[TerminatorX5]

is it what you are talking about??

[bcredliner]

catch can--as in a Campbell's soup can hung by a coat hanger under something that leaks?