Lots of Smoke on Startup

[Engineer Joe]

My '98 328i has been a bit of a problem child since I got is 7 months ago, but I have most of the major items worked out. Once of the last items is that on startup (it takes several tries to get it going) it runs rough (vacuum leak) and smokes a lot. 1 minute later the smoke is gone but the rough running is still there. 3 minutes in it still runs a bit rough but not particularly bad.

I expect it has something to do with the oil seperator, but a friend suggested that it was related to the transmission modulator, which will leak a small amount of tranny fluid into the vacuum system and kill the pvc. I hope not.

Any ideas of good and easy tests to see what might be the source. I have a new PVC ready to go (I tried it but it buzzed so I put the old one back). I am hoping that the PVC by itself will do the trick, but I am a bit wary that I might be looking at a combo problem with something on the fuel side.

Any ideas?

[PHARMDVIPER]

what color is the smoke?

white=coolant/water
blue= oil
black= fuel

[Engineer Joe]

It seems a bit blueish but smells a bit of rich fuel.

[BMWMPow3r]

sounds like you may have leaky valve guides, headgasket, piston rings, fuel injectors, etc. not sure though, need more info.

[r36vo]

Is there an aftermarket chip on ur car?

I have the same prob with my M42 engine with SuperChips, rich fuel startup, a bit smokey for 10 sec then everything goes fine.

[fun2drive]

Do you mean ICV not PCV?
Sounds like a bad vacuum leak and possible CCV. Fix the vacuum leak is cheap if you do it yourself and stick a new CCV in if you think they are related which they could be as the CCV goes into your dip stick via a vacuum hose...

[choffa]

Not trans fluid, no modulator on these transmissions, all electronic. Sort out your vacuum leaks (check intake boot between mass air flow sensor & throttle body, common to have crack at that age), spark plugs, coil boots.

[jmo69]

Old rule of thumb, oil smoke on cold start usually means valve guides, on older GM and Ford engines you could put an umbrella shaped seal over the valve stem under the springs to restict the oil leaking down the stem. About the only good thing about push rod engines. lol

[Engineer Joe]

Thanks for all the suggestions. Sorry for not getting back to them earlier but my mom was in town.
I have had this problem (along with a few others for a while) even before I replaced the head gasket. I got a used but tested flat head (M50 actually) and had new guide seals put in, so I am sure it is not the valve guides. Also guides would smoke all the time, not just on startup.

As far as I know, no mod chip. Good to know no modulator, the idea of tranny fluid going into the intake was disturbing.

Idle control valve could be an issue, but I was thinking oil seperator as I though it would explain oil loss to the intake and vacuum leak. I see your point that maybe the ICV is too far open early on.

Since I need not worry about tranny fluid wasting a new oil seperator, I'll give it a try and hopefully that will narrow down the issues.

Thanks, for the help. I'll post what I find.

[Engineer Joe]

After installing the new CCV (which still buzzes) the symptoms of vacuum leak have cleared up, but the smoking problem persists, though it is a bit better. I am considering if it might be due to some type of leaky injector.