325 bang from exhaust then cut out?

[GoldenArms]

hi, wondering if anyone could help me, i was accelerating in 1st when the car startd to hesitate a about 5k rpm like a misefire then cut out totally,. when it cut out there was a really really loud bang from the exhaust. i tried starting the car back up and the engine sounded like a tractor, like it was knocking then cut out again. after a couple of minutes i tried starting it, and after a few attempts it started and the engine sounded normal. i drove it home and checked round the engine, no oil leaking or anything. engine ran as normal after,
does anyone know what the problem could be?

cheers

[GoldenArms]

its an '87 325 cabby, yea the revcounter dropped straight to zero, as if the car stalled. all dash lights came on like when you put the ignition on.

[jbh]

do you know if it has the early motronic or the later motronic?

[march109]

Simplest and first thing I would check is the back box! Give it a little rattle and knock and listen for anything loose inside it.

Sounds to me like it was clogged by the cr@p they put in the back box coming loose and then blew it out. When it is totally blocked the pressure builds up until the engine can't run or the blockage is forced out. Usually with a bang of some sort.

[blingsta]

possibly a dodgy AFM ?

[GoldenArms]

Simplest and first thing I would check is the back box! Give it a little rattle and knock and listen for anything loose inside it.

Sounds to me like it was clogged by the cr@p they put in the back box coming loose and then blew it out. When it is totally blocked the pressure builds up until the engine can't run or the blockage is forced out. Usually with a bang of some sort.

checked the backbox, nothing loose inside..

car has been running fine all day today. going to give it a full service tomorrow. the car did cut out last week aswel as i slowed down to a speed bump, took a couple of minutes to start back up then too.

[GoldenArms]

do you know if it has the early motronic or the later motronic?

im not sure mate

[Rav335uk]

I bet the ECU 's gone,
I had this on my 2.5 too, went bang, and ended up being the ecu, put in another one, all was well.

[GoldenArms]

I bet the ECU 's gone,
I had this on my 2.5 too, went bang, and ended up being the ecu, put in another one, all was well.

ok thanks, ill try it.

[Brianmoooore]

Did your revcounter drop to zero ? What did the dash lights and other gauges do? What year/model e30 is it?

First guess would be a faulty crank speed sensor, but need more info about EXACTLY what it did!

[danbear]

My 325 done this about 4 months ago, and hasn't done it since

[GoldenArms]

My 325 done this about 4 months ago, and hasn't done it since

been driving for 2days now and has been fine.

[danbear]

It still bugs me now. Would love to know why it happened. This happened while we had the snow, so maybe something got wet or something?

[GoldenArms]

It still bugs me now. Would love to know why it happened. This happened while we had the snow, so maybe something got wet or something?

did out get a loud bang out the exhaust aswel when it cut out ?

march109 mentioned about checking the backbox, and to be honest the backbox has gone quiet abit louder. so maybe it was that.

[danbear]

My car was popping and banging as if it had a missfire. Give the exhaust a check, but i cant see it being that or any part of the exhaust if there's nothing loose inside. Dont worry about it

[GoldenArms]

car has been cutting out randomly while ive been driving. then takes like 5mins to start back up then its fine. has been happening for a few days, so had a full service, changed fuel filter and fuel pump too, but today it cut out again twice. anyone have any idea what it could be ?

[Brianmoooore]

Did your revcounter drop to zero ? What did the dash lights and other gauges do? What year/model e30 is it?

First guess would be a faulty crank speed sensor, but need more info about EXACTLY what it did!

If you'd answer the questions instead of random parts swapping, and possibly introducing new faults to further complicate things, we might get nearer the answer!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[GoldenArms]

i did say before about the dash lights, its just like when the car stalls, all ignition lights are on. . . its a 87' 325, when driving along normally the car now cuts out as if theres no petrol or something. revs drop straight to zero.