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325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 3:29 am
by 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
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 1:06 pm
by 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.
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 1:12 pm
by jbh
do you know if it has the early motronic or the later motronic?
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 2:03 pm
by 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.
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 5:13 pm
by blingsta
possibly a dodgy AFM ?
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 10:41 pm
by GoldenArms
march109 wrote: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.

Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 10:42 pm
by GoldenArms
jbh wrote:do you know if it has the early motronic or the later motronic?
im not sure mate
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 10:47 pm
by 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.
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 11:20 pm
by GoldenArms
Rav335uk wrote: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.
Re: 325 bang from exhaust then cut out?
Posted: Tue May 04, 2010 11:23 pm
by Brianmoooore
willnz wrote: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!
Re: 325 bang from exhaust then cut out?
Posted: Wed May 05, 2010 12:32 am
by danbear
My 325 done this about 4 months ago, and hasn't done it since

Re: 325 bang from exhaust then cut out?
Posted: Wed May 05, 2010 8:33 pm
by GoldenArms
danbear wrote:My 325 done this about 4 months ago, and hasn't done it since

been driving for 2days now and has been fine.

Re: 325 bang from exhaust then cut out?
Posted: Wed May 05, 2010 11:37 pm
by 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?

Re: 325 bang from exhaust then cut out?
Posted: Thu May 06, 2010 10:52 pm
by GoldenArms
danbear wrote: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.
Re: 325 bang from exhaust then cut out?
Posted: Fri May 07, 2010 1:02 am
by 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

Re: 325 bang from exhaust then cut out?
Posted: Sun May 23, 2010 1:02 am
by 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 ?

Re: 325 bang from exhaust then cut out?
Posted: Sun May 23, 2010 9:12 am
by Brianmoooore
Brianmoooore wrote:willnz wrote: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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Re: 325 bang from exhaust then cut out?
Posted: Sun May 23, 2010 3:08 pm
by 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.