2004 N62 engine blue smoke at startup

[Doru]

I searched, but what I found were:

• the 3 liter engines smoking at startup (CCV related)
• the diesel counterparts smoking at startup
• white smoke at startup
• the only N62 related was smoking while idling

This happened with cold engine and lasted a while. The work I did around the engine before this, was: new sparkplugs (the old ones looked OK), new WP, new T-stat, new belts, opened & cleaned the CCV valves (both left & right) - they had minimal crud - a light brown film, so I re-used them.

Not sure where to look. The engine idles smooth, GT1 or INPA didn't show anything abnormal. But that blue smoke sure doesn't look healthy. And I don't want to wait until something will let me stranded. Also, I wouldn't mind pointers to threads where this issue was fixed (I don't think I'm the only one, but as I said, I couldn't find anything relevant ).

TIA

[TwinTurboGTR]

When you removed the plugs, as there any oil in there ports? How were the valve cover gaskets? Normally when fiddling around there, oil does find its way down and burns off. Did you start it again and blue smoke came out or did you just start it for the first time, saw the smoke then shut it down?

Let us know

[bcredliner]

Are you saying there was no blue smoke prior to your work and it has continued to smoke after driving 10 miles or leaving it running for 10-15 minutes?

[Doru]

Originally Posted by TwinTurboGTR

When you removed the plugs, as there any oil in there ports? How were the valve cover gaskets? Normally when fiddling around there, oil does find its way down and burns off. Did you start it again and blue smoke came out or did you just start it for the first time, saw the smoke then shut it down?

Let us know

When I removed the plugs, there was no oil anywhere. I didn't inspect closely the valve covers, but I haven't seen any oil stains. The engine is bone dry at the bottoom as well. The only noticeable oilstain was behind the passenger side big cylinder on top of the valve cover (sorry for my ignorance -I don't know what that part is or what it does. There are 2 of them, one on top of each of the valvecovers and look like ahuge condenser). That oilstain was old, a heavy cake of oil & old dust, and was pretty much around an electrical plug, which I think is attached to that cylinder. Maybe an old oil leak around that area?
I think that blue smoke was always coming out when starting the engine cold. it's a distintct heavy smell, which my other BMW doesn't have. And it lasts a few minutes.
Once the engine is warm, there's no problem anymore.

[Doru]

Originally Posted by bcredliner

Are you saying there was no blue smoke prior to your work and it has continued to smoke after driving 10 miles or leaving it running for 10-15 minutes?

The blue smoke was there since I purchased the vehicle, only it's hard to see it when you're in the driver seat. I could notice a heavy odor, and yestrday when fixing the cooling issue, I left the car running and worked outside. That, s how I noticed it. With the engine warm, ther's no smoke.

[Roadkill]

Valve seals perhaps. Not a cheap fix.

[TwinTurboGTR]

Ok, so if the problem was always there... then I agree... Sounds like it if valve seals. As the motor cools, the oil works past the seals and when you start up, oil is burning off. Have you tried to leave the X sit idle for a few minutes and then blip the gas and see if the smoke is there? Oil is leaking past somewhere, but with the N62 motor, valve seals are another culprit to add to the list.

That or your CCV's are leaking oil, but you said you inspected those I believe in a different post a while back??? Maybe I am wrong.

[Christiano]

Clean all injectors. Sometimes, my 4.8 did that big blue puf on start. But I could note that the engine started weird, like with one spark plug dead. Straight to dealer, some tests and they found all injectors dirty. After a treatment, they run like a champ and I never saw that puf again.
Good luck!

[Doru]

Originally Posted by TwinTurboGTR

Stuff deleted

Have you tried to leave the X sit idle for a few minutes and then blip the gas and see if the smoke is there? Oil is leaking past somewhere, but with the N62 motor, valve seals are another culprit to add to the list.

That or your CCV's are leaking oil, but you said you inspected those I believe in a different post a while back??? Maybe I am wrong.

Yes the smoke is there after idling. But it's different in color. At startup it's definitely bluish. At idle after a few minutes (and with the engine hot), giving that quick throttle, it looks almost like water vapor, and it's very brief. Not the bluish or dark color. Maybe a tinge of grey.

Yes, I inspected the valve seals, and they looked OK to me. They were soft and pliable, had some dark oil stains, the passenger side had a smidge of crud build up at the bottom around the round corners, nothing major. Cleaned it and placed it back.

[Doru]

Originally Posted by Christiano

Clean all injectors. Sometimes, my 4.8 did that big blue puf on start. But I could note that the engine started weird, like with one spark plug dead. Straight to dealer, some tests and they found all injectors dirty. After a treatment, they run like a champ and I never saw that puf again.
Good luck!

My engine starts beautiful now, but I have no idea how she would behave in a cold environment.

Also, after the oil change & spark plug change, and all the other stuff I did, I noticed a huge improvement how the engine is turning. It's very smooth.
When I purchased the vehicle, I thought it was driving very well, but obviously I was wrong. To confirm, my wife who has no clue about cars, took the vehicle today for a spin. Upon returning she asked me what did I do to it, because it's a very noticeable improvement. Usually she never noticed stuff like that, because the changes are subtle. I don't think the injectors are clogged, but I could definitely run some Lubro-Moly injector cleaner (that's what the dealership is usually using). I have a few spare cans in my garage.