E46 M54 engine automatic stall?

[bmwownage 0]

I have been experiencing, probably minor problems (at the moment) with the car when I brake from speed to very low speed or to a halt, just before it stops, sometimes it makes a slight shake and rev drops a tad below the 500rpm line. It seems to be worse when the engine is warmed up, presumably because of the higher idling rev (~1000rpm) with a cold engine.

I have googled this problem and found out, indeed, lots of M54 325i and 330i have this problem, their cars even stalled, auto tranny! It happens in the manual too, just differently, but let's just talk about the auto here. Suggested reasons were software related, faulty sensors of all sorts, faulty vanos and the list continues, and the real cause of the problem is unknown.

The only thing unusual that I have done, which is not unusual at all, was that I put some water in for the coolant quite a while ago, which looked empty. Thinking back I am not sure whether it started as a result of this, but I mean, putting water in as coolant shouldn't be an issue in Auckland right? Quite weird, my friend has an exact same 330i which has done over 75000kms, while mine is a bit over 31000kms.

Does anybody, or do Botany Motorworx have any idea how to fix this? I don't think my vehicle is going to stall, but it sounds like it will one day, and i want to get it fixed before that happens.

Edited June 30, 2008 by bmwownage

[*Glenn* 854]

I have been experiencing, probably minor problems (at the moment) with the car when I brake from speed to very low speed or to a halt, just before it stops, sometimes it makes a slight shake and rev drops a tad below the 500rpm line. It seems to be worse when the engine is warmed up, presumably because of the higher idling rev (~1000rpm) with a cold engine.

I have googled this problem and found out, indeed, lots of M54 325i and 330i have this problem, their cars even stalled, auto tranny! It happens in the manual too, just differently, but let's just talk about the auto here. Suggested reasons were software related, faulty sensors of all sorts, faulty vanos and the list continues, and the real cause of the problem is unknown.

The only thing unusual that I have done, which is not unusual at all, was that I put some water in for the coolant quite a while ago, which looked empty. Thinking back I am not sure whether it started as a result of this, but I mean, putting water in as coolant shouldn't be an issue in Auckland right? Quite weird, my friend has an exact same 330i which has done over 75000kms, while mine is a bit over 31000kms.

Does anybody, or do Botany Motorworx have any idea how to fix this? I don't think my vehicle is going to stall, but it sounds like it will one day, and i want to get it fixed before that happens.

I'd suggest scanning the systems for fault codes first. Could be a camshaft speed sensor or air mass sensor fault, going by your explanation. The cooling system is another matter though and probably not related at all.

Give me a call Ph. (09)2722546

Cheers

Glenn

[wild_weston 0]

My money would be on your cam intake sensor.

Mine had a slightly different problem of when the car was started from warm then it would stall immediately and then again once you tried to start off. Suffered from a lack of power until it cooled down.

The problem was that the cam intake sensor was going faulty and being affected by the heat of the engine.

Got a new one put in (plus a new exhaust cam sensor for good luck) and problem went away.

Not exactly the same problem as yours but it might be a faulty sensor being affected by engine heat.

First thing though, rather than speculation, is to check for any fault codes. The E46 doesn't tell you if there are faults (like the E36) - you have to check for them.

Cheers

Edited June 30, 2008 by wild_weston

[elmarco 56]

Mine actually did this once too. It was in the middle of a really hot day and I put it down to vapour lock in the fuel line (the car had been parked for a while after driving and only did it on restarting). Never done it since.

Best you get it down to Glenn for a scan.