BMW E46 Fanatics Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
Thsi issue only occurs after the car has been off for about 8 or more hours. It seems to happen more frequently in cooler tempetures, say less than 65 degress F., seemingly getting worse as the temperature drops, and more dampness in the air. This problem is intermintent occuring only about 4 out of 8 "overnight" starts. A BMW feild enginer is coming out to "observe/verify/duplicate" the issue as the dealership is stumped. Fuel pressure bleed off ok/ new filter installed/ manifold and vaccum lines tested with smoke machine no leaks/ switched to lower octance gas with no change/ bmw cleaned upper cylnder head and injectors with bg cleaner system. Nothing works, switched brands of gas several times, etc...

What happens when the engine starts:
1. Engine starts perfectly, rpms around 1000-1100.

2. After about 0.5 seconds, the engine stumbles, misfires, almost stalling, the rpms shoot down to about 400-600. It is never consistant on how bad the stumble/misfire is, sometimes barley noticeable, others so bad it almost backfires.

3. After the engine stumbles/misfires for approximatly 0.5 seconds, the rpms jump back up to about 1200 rpms, and then drop to around 900-1000 rpms, running normal

4. It does not matter if the a/c is on or off, or if any accesories are operating at start-up, what angle the car is sitting, hill, side tilt, it is almost always level.


I used the search feature for about three hours reading posts.

Does anyone have any ideas on what might be causing this?

Any suggestions on dealing with the Rep if it happens to not occur when he attempts to duplicate the issue? Would video taping the issue be completely overboard?

Thank you all!
 

·
Registered
Joined
·
26 Posts
Discussion Starter #3
sorry for not including that, yes, the plugs are brand new OEM from dealer, actually they had to put in a new motor due to an Intake valve hanging up causing major damage.

It is a factory refurbished motor. Odd part is the stumbling at startup occured with the old motor also.
 

·
Registered
Joined
·
12 Posts
same problem here most likely your vanos is broken a thinner oil will help but won't solve the problem 0w40 mobil1
 

·
Registered
Joined
·
119 Posts
What about you mass air flow sensor a dirty connection a broken wire hi resistance can do a lot of the stuff your talking about. Throttle body position sensor can also be a problem. To test either one your going to need one f'in badass multimeterto check for inaccurate voltage.

Besides something giving anyone this much trouble you know is going to be the one you least expect. Good Luck Buddy hope what i had to say was a little helpful.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #6
thanks for any ideas, I'm just battling out with the dealership, and BMWNA right now. They say sixty days is normal to wait to have the car checked out.????
 
1 - 6 of 6 Posts
Top