Stalling in the rain

[White535Mtl]

Ok this time it's getting pretty serious. I've posted about this before...

So here are a few symptoms when it starts acting up
-It only does that when it's wet/raining; I'd drive the car while it's raining. for the first few minutes, it's fine (15 minutes). If it keeps raining and I'm still driving, the check engine light would come on intermitently. Then if I'm still driving, it would slowly start sputtering.
-When I drive for extended periods under rain, it would buck and sputter while driving, at any speed. At the beginning of the sputtering, I'd sometimes engage the clutch and rev the engine. And it would go away.
-The third stage, the sputters, and then comes to a complete stall. Once again, this could happen at any speed. It stalled when I was parked and left it at idle, and it stalled while driving at 50mph.
-I've noticed that when it starts sputtering and stalling, I would sometimes keep it at WOT, it would sputter a little, and then it would go.
-When I use the stomp diagnosis test, it shows 1222, and I checked in my Bentley manual, it says that the car is running rich.

I'm guessing it has something to do with fuel delivery...
Anyone has any pointers as to where to start? I'm still new to this BMW.

Thanks in advance!

[Martin in Bellevue]

I'd look at the ignition. Is the plastic cover over the distributor? Are the cap & rotor 16 years old? Can you see the spark plug wires lighting off cracks when running in the dark? German plastic doesn't age well.

[White535Mtl]

I'd look at the ignition. Is the plastic cover over the distributor? Are the cap & rotor 16 years old? Can you see the spark plug wires lighting off cracks when running in the dark? German plastic doesn't age well.

I've poured over a gallon of water over these babies. I surely expected the engine to go crazy, but that never happened...

[632 Regal]

have you tried to reboot the computer? Maybe that will clear that code and you will get a better result with the code check.

To me it definetly sounds electrical in the ignition department, especially from a running rich code. The crank sensor is the first in line to get water on it, check it for looseness, if its cracked and also the wiring from that.


I've poured over a gallon of water over these babies. I surely expected the engine to go crazy, but that never happened...

[Kalevera]

Inspect the O2 sensor harness and wiring, where it runs to the exhaust. Downpipe/header heat and time can brittle the insulating plastic over time, cracking it. Saw an OBDII car like this a few weeks back -- one rear O2 lead was chaffed due to a stupid person reinstalling the exhaust (M74) and it popped the CE off and on. Water, of course, conducts. When the car is driven in rain, that part of the engine bay and underbody can get very wet (no shield, not that the front shield does much of anything to begin with). One or more wires are probably grounding out intermittantly against the chassis.

Don't forget that the 02 and MAF effectively tell the DME what's going on with airflow. The DME picking up a string of outrageous numbers from the 02 lead, versus what the maf is saying, would result in a confused computer and a CE light. WOT disregards 02 completely, if I remember the process correctly.

more sometime else, I'm tired.

best, whit

[SRR2]

I've had two cars, not Bimmers, in the past that had identical symptoms. They were simpler than yours, so no fuel injection. However in both cases it was an intermittent coil. One of them was a particularly difficult one to find because the crack on the coil would cause a problem only when it was warm. You could pour water on it cold and nothing would act up. In the rain, on a warm day however, it would crap out exactly the same way your car does.

[Reidal]

I've had similar problems caused by a cracked coil housing. It was oil filled. Some oil canme out, water would get in under certain conditions.

Only happened when my wife was driving it. You can imagine the drama's that caused :p

[White535Mtl]

have you tried to reboot the computer? Maybe that will clear that code and you will get a better result with the code check.

To me it definetly sounds electrical in the ignition department, especially from a running rich code. The crank sensor is the first in line to get water on it, check it for looseness, if its cracked and also the wiring from that.

How do I go about rebooting the computer?
The crank sensor was replaced a month ago; the car would start whenever it would want to. Only thing is, it was my mechanic who found the problem and replaced the faulty crank position sensor. It could still be that, although I haven't had the time to check it, due to the continuous rain but that is most certainly one of my priorities when the sun comes out.


Inspect the O2 sensor harness and wiring, where it runs to the exhaust. Downpipe/header heat and time can brittle the insulating plastic over time, cracking it. Saw an OBDII car like this a few weeks back -- one rear O2 lead was chaffed due to a stupid person reinstalling the exhaust (M74) and it popped the CE off and on. Water, of course, conducts. When the car is driven in rain, that part of the engine bay and underbody can get very wet (no shield, not that the front shield does much of anything to begin with). One or more wires are probably grounding out intermittantly against the chassis.

Don't forget that the 02 and MAF effectively tell the DME what's going on with airflow. The DME picking up a string of outrageous numbers from the 02 lead, versus what the maf is saying, would result in a confused computer and a CE light. WOT disregards 02 completely, if I remember the process correctly.

more sometime else, I'm tired.

best, whit

The 02 sensor was the second on my checklist; I spent a good half of the day reading up on potential issues in the Bentley. But due to the same reason mentionned above, didn't get the chance to get underneath the car.


I've had two cars, not Bimmers, in the past that had identical symptoms. They were simpler than yours, so no fuel injection. However in both cases it was an intermittent coil. One of them was a particularly difficult one to find because the crack on the coil would cause a problem only when it was warm. You could pour water on it cold and nothing would act up. In the rain, on a warm day however, it would crap out exactly the same way your car does.

When I called my mechanic for advice (I call him way too often), he pointed to me that it was a probable source of my headaches. But really, I don't know where to find it, and what it actually does...




So, I spent the whole day trying to figure out some things underneath the wood. I'm no gizmo/techie so I read up a lot of things in the Bentley. The distributor cap and rotors are high in my priority list. But here's something that I found which was very interesting.
- on M30s, right next to the positive pole, there are two wires going out from that "box". The lower one goes to tap underneath the air intake. It seems like it's a ground. But the wire has been stripped of its rubberish protection and it has corroded. The copper has oxidized and the wire is now green.

Could this be part of the answer?

[632 Regal]

green and corroded is BAD! I would firstly concentrate on that aspect, fix it and go from there, glad you have it narrowed some now.


How do I go about rebooting the computer?
The crank sensor was replaced a month ago; the car would start whenever it would want to. Only thing is, it was my mechanic who found the problem and replaced the faulty crank position sensor. It could still be that, although I haven't had the time to check it, due to the continuous rain but that is most certainly one of my priorities when the sun comes out.



The 02 sensor was the second on my checklist; I spent a good half of the day reading up on potential issues in the Bentley. But due to the same reason mentionned above, didn't get the chance to get underneath the car.



When I called my mechanic for advice (I call him way too often), he pointed to me that it was a probable source of my headaches. But really, I don't know where to find it, and what it actually does...




So, I spent the whole day trying to figure out some things underneath the wood. I'm no gizmo/techie so I read up a lot of things in the Bentley. The distributor cap and rotors are high in my priority list. But here's something that I found which was very interesting.
- on M30s, right next to the positive pole, there are two wires going out from that "box". The lower one goes to tap underneath the air intake. It seems like it's a ground. But the wire has been stripped of its rubberish protection and it has corroded. The copper has oxidized and the wire is now green.

Could this be part of the answer?

[White535Mtl]

Just came back from the stealership and I got quoted 330 CDN for an O2 sensor. Err... any other place where I could find an O2 sensor for a reasonable price?

[632 Regal]

http://www.autohausaz.com/catalog/lookup_parts.cfm?SubcategoryID=5132&VehicleID=1012273&CFID=278852&CFToken=67314882

[uscharalph]

"Only happened when my wife was driving it. You can imagine the drama's that caused"

Murphy's Law!

[Kalevera]

Once again, let me reiterate that I think it's a wiring problem and not the sensor itself. A bad 02 sensor is consistently bad. Read my earlier post -- I diagnosed it to the T for you, big baby.


best, whit

[White535Mtl]

Once again, let me reiterate that I think it's a wiring problem and not the sensor itself. A bad 02 sensor is consistently bad. Read my earlier post -- I diagnosed it to the T for you, big baby.


best, whit

LoL thanks.