E46 Smoking on startup, drinking oil like an alcoholic...

[dchurch24]

Hi all,

I bought a 325i on NYE of last year. Recently, it's started puffing out a cloud of smoke on startup - sometimes after sitting for a while, and other times, when warm and having only been stopped for a few minutes. There appears to be no pattern to the behaviour and I figured it was 'just one of those things'.

Now, however, the yellow oil light is coming on frequently. I check the oil, and sure enough, it looks a little low, so I top it up.
There are no leaks, I have had it checked twice - once by a BMW specialist, and once by an independent - both informed me that there were no oil leaks.

A few weeks ago, I started her up to drive 1/2 mile and it was running on what felt like 5 plugs. I stopped. Turned the car off, had a look under the bonnet in case I could see something obvious (couldn't), and get back in and started her up again. This time, she was running perfectly - until yesterday.
Was running fine on the way home from work, I stopped at a shop to pick up a few bits. Got back in and it's been running on 5 ever since.

Is it completely shagged? Or is this a common thing that can be fixed without breaking the bank?

TIA.

[nonturbodan]

Most likely cause of oil consumption is a bad crankcase vent valve. This is likely unrelated to the misfiring and cylinder deactivation.

The misfiring is most likely caused by a bad ignition coil, though there are many potential causes. You need to find out which cylinder is getting shut down and then move the coils around to see if the fault follows. If its not a coil it could be a plug, a fuel injector or a more serious internal engine problem. These are very good engines and the problem is almost certainly external.

[MIKYZZ4]

Perform a scan for codes, preferably with a BMW specific scan tool/software.
I also suspect a CCV system failure, and a cracked CCV Hose can cause misfiring,
due to air infiltration aka a vacuum leak. Can you supply more vehicle specifics,
or last 7 digits of VIN#? That will allow me to search for specific diagrams.

[Honolulu]

Sounds like the "oilchoholic" model. A lot like an alcoholic, but different. Worn valve seals used to turn all the 2002's into oilchoholics after 70,000 or so miles. About that time the synchros were packing up to leave too. Ahhh, the good old days.

For this model, though, the crankcase vent system is suspect and a lot has been written about it. use the search function.

[legoman67]

+1 on a bad coil for the misfire. They do die. Easy enough to diagnose with a scanner.(it will throw a fault)

CCV could be the oil consumption, you would need to have the crankcase pressure tested for that.