djlowd
04-02-2017, 03:47 PM
Hi everybody,
I coming to you tonight because I'm facing some problems for months on my '91 525i automatic (M50B25), and nobody (me included) is able to find the problem... I'm gonna try to sum up the problem as best as I can :
- When the car is cold, no problem until it's hot and I put the car off
- When the car is hot, I put it off and after the restart problems are coming
- Engine is randomly stalling at idle (neutral), cutting off like I would be putting off the DME relay
- Idle randomly drops down like it'll stall for one second and comes back at normal RPM
- Sometimes it'll stall at low RPM, when I'm engaging D or R and moving slowly
- Sometimes it'll stall when I'm stomping the gas pedal, RPM drops down and engine stalls instantly
- Sometimes when I'm driving in S mode, I'm stomping the pedal to give a kick-down, and then when the RPMs are going up the car becomes crazy, seems to stall and then cames back to life with a belt noise and a shock in the car (I think it's because the engine comes back up brutally). The S mode is automatically replaced by the E mode, what seems to be normal as the engine has stalled ?
- Once the car stalled, the restart is a bit more difficult than usual. When everything works nice, the starting is perfect
Here it is... I tried to made it simple, I've got 0 error code on the diagnostic !!! Trans program comes up randomly when the problem appears, but that's not every time... I hope you'll be able to help me, I've got the car for 6 months and nobody is able to find the problem !
This week I changed the DME relay, I thought it could be the fault but no chance... I tested all the sensors with the Bentley manual, everything seems to be OK... Spark plugs are nice, coils seems to be good too, and the problem doesn't seem to be an ignition one...
Last night, I was going on a roundabout, engine was near to stall when I put the gaz, and then I was stuck in 1st speed !! No trans program at all, no shock or anything... I drove about 300m like this and then the 2nd engaged, and then everything was OK ! It was like the transmission unit wasn't receiving the engine speed information... But the RPM on the cluster were OK. According to the Bentley manual, my CPS is ok but could he be working bad only when the car is hot ?
I've got no vacuum leaks, I already disassembled the whole intake manifold to verify... ICV has been cleaned too !
Hope you guys will be able to help me !!
Cheers,
Romain
EDIT : O2 sensor is brand new too...
I coming to you tonight because I'm facing some problems for months on my '91 525i automatic (M50B25), and nobody (me included) is able to find the problem... I'm gonna try to sum up the problem as best as I can :
- When the car is cold, no problem until it's hot and I put the car off
- When the car is hot, I put it off and after the restart problems are coming
- Engine is randomly stalling at idle (neutral), cutting off like I would be putting off the DME relay
- Idle randomly drops down like it'll stall for one second and comes back at normal RPM
- Sometimes it'll stall at low RPM, when I'm engaging D or R and moving slowly
- Sometimes it'll stall when I'm stomping the gas pedal, RPM drops down and engine stalls instantly
- Sometimes when I'm driving in S mode, I'm stomping the pedal to give a kick-down, and then when the RPMs are going up the car becomes crazy, seems to stall and then cames back to life with a belt noise and a shock in the car (I think it's because the engine comes back up brutally). The S mode is automatically replaced by the E mode, what seems to be normal as the engine has stalled ?
- Once the car stalled, the restart is a bit more difficult than usual. When everything works nice, the starting is perfect
Here it is... I tried to made it simple, I've got 0 error code on the diagnostic !!! Trans program comes up randomly when the problem appears, but that's not every time... I hope you'll be able to help me, I've got the car for 6 months and nobody is able to find the problem !
This week I changed the DME relay, I thought it could be the fault but no chance... I tested all the sensors with the Bentley manual, everything seems to be OK... Spark plugs are nice, coils seems to be good too, and the problem doesn't seem to be an ignition one...
Last night, I was going on a roundabout, engine was near to stall when I put the gaz, and then I was stuck in 1st speed !! No trans program at all, no shock or anything... I drove about 300m like this and then the 2nd engaged, and then everything was OK ! It was like the transmission unit wasn't receiving the engine speed information... But the RPM on the cluster were OK. According to the Bentley manual, my CPS is ok but could he be working bad only when the car is hot ?
I've got no vacuum leaks, I already disassembled the whole intake manifold to verify... ICV has been cleaned too !
Hope you guys will be able to help me !!
Cheers,
Romain
EDIT : O2 sensor is brand new too...