Really poor cold running, less poor warm

[Ross]

M60 530i '94 manual trans 7/93 USA 104k

When cold it will start but refuse to idle w/o stalling, throttle is sluggish, smells like a coal burner, can provoke black smoke with revving.
After warming it will idle slow and rough, <500rpm, throttle still sluggish, it will backfire lightly through exhaust on the over-run from a free rev. (extra fuel in exh/cats?)
Code 1213 lambda2 present.
Sprayed around the intake and particularly the rear of it until brake cleaner ran out, no changes noticed.
I have the cars service records, there is no record of intake leaks having been repaired but this is what I suspect contrary to the results of spraying combustibles aroud the gaskets.
SO,... what do you guys think?

[bubba966]

Sounds a lot like a vacuum leak I had on an M50. And there's a lot of places a vac leak can occur besides the intake gasket...

[ThoreauHD]

Buy the 02 sensors, fuel filters, the charcoal canister(it's 20 bucks at bavauto), spark plugs(single tipped, preferably denso iridium or ngk- not the 4 prong crap).

I'd suspect a combo vacuum leak, O2 sensors dying, and plugs trying to spark covered in oil. Possibly the Idle Control Valve, but let an indy figure that one out.

You'll probably need valve cover gaskets, if you are blowing crap through the pipe. Those are cheap as well. But hold off on that until later you actually know.

It's easy to replace. I just bought some, as it happens. Let the mechanic replace the plugs, cause if there's oil on them there plugs, you need to replace the valve gasket with the pieces parts below.

11 12 9 069 871 Valve Cover Gasket - right - Cyl 1-4 $19.95 1 $19.95
11 12 9 069 872 Valve Cover Gasket - Left - Cyl 5-8 $19.95 1 $19.95
11 12 1 726 537 Valve Cover Bolt Rubber Seal - sold individually $1.95 22 $42.90

Anyway, get those basic parts and bring them to an independent reputable BMW mechanic. Check your local bmwcca website for decent folks. Have him install those items and then diag if symptoms persist.

Or, you can just bring it in and make a wish, and come back 4 more times.



Sorry for the diatribe, but I wanted to cover all the bases so you don't waste time.