E36 M3 Engine Rebuild Running In

[Och]

I have just had an engine rebuild on my E36 M3 after a bearing unwound on the crank shaft.

Two questions for those that know the answers for me please:

1. What procedure do I follow to run the engine in before going back to track days with BMW club. BMW suggest running it at max 3000rpm for 2000kms - seems a little unsophisticated for this engine to me?

2. The idle is rough. Has stalled a couple of times. BMW tells me its air in the vario timing system and if it doesnt clear out over time I am up for another $2000 for a new timing chain unit (sorry this is as well as I can describe it) - this makes no sense to me. There was no idling problem before the rebuild. Is this correct? If not what is the problem likely to be? The car is smooth under power.

Thanking you in advance
Och used

[Och]

No replies? I am surprised there is no informationon this topic??

Och

[97alpineM3]

As for breaking in your car... I would say give her a thousand.. a buddy of mine was in the same possition.. ran it for a good month or so.. and then just started gradually feeding her higher RPMs...

As for your idle being rough... I've never heard of air in your timing system... that sounds like a horrible guess to me...

There are a few write ups in our FAQ section pertaining to a rough idle and the cleaning and or replacing of your Idle control valve...

As for this happening after a rebuild... I dont know.. unless something is inhibiting the travel of the valve since it was obviously removed and then put back on... the reason I say this.. is because once you accelerate in the car... everything is fine... which means to me that your spark plugs are good.. injectors are good... and normal air flow is good... I would, as a preventative measure.. check your spark plugs... just to make sure they arnt running too hot.. and make sure your using OEM ones too.. due to the ignition systems pickyness... There are a few write ups in the FAQ about cleaning your ICV... before you go replace your timing system... I'd do some other searching around for other opinions.. and or cleaning of the intake system.

Good Luck,

Les

[Speedy-325is]

check the rough idle thread.....when they removed your engine to rebuild it, they (most shops) dont fine tune the adjustment tensioner for the throttle making it bounce because the ICV (idle control valve that electronically controls the cars idling)
is trying to keep the car from stalling out when the car tries.

if u look on your throttle body, follow the throttle cable just behind where it connects to the throttle bdy. there will be a small ovalish black piece that you can spin to finely tune the idle with by tightening it.
its like an idle mixture screw on a old 4-barrel carb...but totally different.

turn it while your car is idling 1/2!!!! ONE-HALF!!!!! a turn at a time. then rev the engine up a bit and see where it settles. adjust till you are in the 700-800rpm range and then shut the car off completely.

when you start it up again, the ICV will reset to the new idle speed and hopefully the bouncing stops. adjust more if needed, but pay attention to you RPM'S....IF U HIT 1100RPM's, then you need to look elseware.

the air in the timing????? WTF?????? what sort of shop is this and do you trust them???????? how much was ur rebuild? and if the problem was not there when you brought it in....ITS THEIR PROBLEM!!!!!!! go talk to another shop...not the dealer, and explain the situation if my little trick didnt work. you will get a second opinion and maybe a few ideas.

hope it helps. lemme know what happens and ill talk to my boss on Monday.
Mark