BMW M5 Forum and M6 Forums banner

1 - 20 of 32 Posts

·
Registered
Joined
·
282 Posts
Discussion Starter #1
I had SES come on today while entering the freeway. Not quite wide open, but probably around 6,000 in third when it appeared. It ran a bit rough after that. Pulled off the freeway and babied it home, maybe 2 miles. SES went off probably within the first mile and it seemed to smooth back out. When I got to the house I checked it for codes.

Only a single code is pulled, P1345. From searching the forum, it is described "Misfire Cylinder 2 With Fuel Cut-off".

The way it was running was reminiscent of other cars I have that have had the ignition coil go bad. However, once they had gone bad, they had gone bad and not come back like what I experience today with the M5. So could this be just an ignition coil?

When I searched the forum, it seemed every thread that included this code also included several other with it. In my case it is just the single P1345.
 

·
Registered
Joined
·
3,946 Posts
I had SES come on today while entering the freeway. Not quite wide open, but probably around 6,000 in third when it appeared. It ran a bit rough after that. Pulled off the freeway and babied it home, maybe 2 miles. SES went off probably within the first mile and it seemed to smooth back out. When I got to the house I checked it for codes.



Only a single code is pulled, P1345. From searching the forum, it is described "Misfire Cylinder 2 With Fuel Cut-off".



The way it was running was reminiscent of other cars I have that have had the ignition coil go bad. However, once they had gone bad, they had gone bad and not come back like what I experience today with the M5. So could this be just an ignition coil?



When I searched the forum, it seemed every thread that included this code also included several other with it. In my case it is just the single P1345.

Easy enough to swap the coil to another location on the same bank and see if the code follows. I'd probably pull the #2 plug, too, for a look.
 

·
Registered
Joined
·
4,488 Posts
I had SES come on today while entering the freeway. Not quite wide open, but probably around 6,000 in third when it appeared. It ran a bit rough after that. Pulled off the freeway and babied it home, maybe 2 miles. SES went off probably within the first mile and it seemed to smooth back out. When I got to the house I checked it for codes.

Only a single code is pulled, P1345. From searching the forum, it is described "Misfire Cylinder 2 With Fuel Cut-off".

The way it was running was reminiscent of other cars I have that have had the ignition coil go bad. However, once they had gone bad, they had gone bad and not come back like what I experience today with the M5. So could this be just an ignition coil?

When I searched the forum, it seemed every thread that included this code also included several other with it. In my case it is just the single P1345.
Sounds like the coil. There's been a few threads on bad coils lately. Each coil only has to generate about 5,000 V to get the plug to fire when putting around town but it takes 20-30,000 V to make the spark under full load conditions because of the much higher cylinder pressures. So that's when a coil with degrading secondary side winding insulation will short to ground.

Yeah, I've noticed the rash of multiple cylinder misfires lately with bad coils but I suspect your failure only happening under high load, high rpm conditions makes it very easy for the DME to detect the misfire unambiguously without cross-feed from other adjacent cylinders.
 

·
Registered
Joined
·
10,307 Posts
2 or 5 when alone can be indications of something else. Weak battery has shown to cause a misfire on 5. No idea why, but there is a thread around here that went on forever, last shop but a battery in and the problem was gone. Battery was not mentioned in the thread.
Before you do anything wait to see if this recurs, it could be a one time stick of an injector. Once the car cuts the fuel it is gone until you restart it. Not sure why you felt it went away or recovered but with this engine maybe 7 cyls was enough.
If it does come back, and you don't know how old the spark plugs are change them and move coil 2 to coil 4, 3 would be OK to but 4 is better, just not cyl 1. You could also move it to the other bank, more work later but if you are inclined use cyl 5 or 6. Definitely not 8 and 7 is a weak choice. Then see if the code moves with the coil.
 

·
Registered
Joined
·
282 Posts
Discussion Starter #5
Thanks. I also bought a Peake reader today. I'll see if it reads anything in addition to what my OBD scanner picked up.
 

·
Registered
Joined
·
282 Posts
Discussion Starter #6
Got my Peake reader today. I indeed got a code related to cylinder #2 and a host of others.

Here is the list:
81 - Catalyst protection engaged, fuel tank low
86 - Instrument cluster timeout
75 - Servotronic speed signal
d0 - Misfire during warm up #4
d1 - Misfire during warm up #5
d3 - Misfire during warm up #7
d5 - Misfire during warm up, multiple cylinders
E8 - Evaporative Emissions purge valve functional check
C5 - Misfire cylinder #2

I am not sure where to start as I'm certain that a bunch of these have to be related.
 

·
Registered
Joined
·
10,307 Posts
Start by clearing the codes and driving the car again. See what comes back you don't have to wait for the light. It will take at least two drive cycles for something to appear.
 

·
Registered
Joined
·
282 Posts
Discussion Starter #8
I'll do that.

After doing some searching last night I think I have a bead on what's going on. I am pretty sure that there is a vacuum leak (looks like there is a weak plastic elbow that disintegrates). Also, looks like a few of the codes are related to the E8 evap purge valve.

This is a good thread DIY on the E8 Evap Purge Valve:
http://www.m5board.com/vbulletin/e3...el-tank-breather-valve-diy-peake-code-e8.html

Here are a couple of good threads related to pulling "misfire on cold startup"
http://www.m5board.com/vbulletin/e3...m-up-misfires-5-6-3-after-maintenance-15.html
http://www.m5board.com/vbulletin/e3...-vacuum-leak-causing-fuel-control-code-2.html
 

·
Registered
Joined
·
282 Posts
Discussion Starter #9
So I pulled the plenum. First impression: man I cant believe how clean the motor is. I was impressed with how clean it was superficially when I bought it. I thought that they must have done some of that engine cleaning junk on it. But nope, it is clean in the deepest darkest reaches.

I pulled the evap purge purge valve. I'll get the the new part tomorrow.

While in there I pulled the "elbow" that seems to be a weak link. Mine is still pearly white with no cracks. I was actually hoping that this would have been in worse shape as it would have confirmed the warm up misfires. It all has to be related somewhere else...

Anyway, I think I'll head to the local hardware store to see if there is any kind of NPT elbow that matches in brass or other metal. This is a fix that we used on the 944 Turbo. This elbow is larger than the vacuum lines on the 944 but I'll see what I can find.
 

·
Registered
Joined
·
10,307 Posts
Before you buy a new part check to see if it works. They just stick usually. I took mine apart and cleaned it and lubed the walls where the diaphram slides and it has worked fine ever since. Just blow in it and then activate it with 12v and blow again. All it does is open and close an air way.
 

·
Registered
Joined
·
221 Posts
Got my Peake reader today. I indeed got a code related to cylinder #2 and a host of others.

Here is the list:
81 - Catalyst protection engaged, fuel tank low
86 - Instrument cluster timeout
75 - Servotronic speed signal
d0 - Misfire during warm up #4
d1 - Misfire during warm up #5
d3 - Misfire during warm up #7
d5 - Misfire during warm up, multiple cylinders
E8 - Evaporative Emissions purge valve functional check
C5 - Misfire cylinder #2

I am not sure where to start as I'm certain that a bunch of these have to be related.
Had the misfire codes and they were all cleared when I replaced the spark plugs and ignition coils. Easy DIY.
 

·
Registered
Joined
·
282 Posts
Discussion Starter #13
I replaced the faulty fuel tank vent valve, P/N 13907830766 over the weekend. I considered the rework as Sailor24 had mentioned. However, having done rework on parts like this before (just meaning buried in the engine) and having them fail again several months later, I opted for the new part. This job isn't difficult but it is something I don't want to do twice unnecessarily.

While I was in there, I replaced the plastic elbow that seems to go bad with a brass one. I found a 3/8 barb at home depot for <$2.00. Because it doesn't have the same ends on it to secure it in the tubes, I used two small SS hose clamps on it. In the picture, it looks much smaller than the original, but really its not except for the ends. I should have also done this with the right angle connector that goes into the #6 cylinder but I forgot and didn't feel like making another run out. I am very fortunate that my rubber is all still very pliable for now.

I have cleared all the codes and was only able to get it out for a short blast. I'll take it out for a nice drive this weekend. All codes are clear still but I am thinking that the coil code will come back eventually.
 

Attachments

·
Registered
Joined
·
282 Posts
Discussion Starter #14
Had a chance to get the car out and drive it a bit today. After a bit of spirited driving 20 minutes or so, came to a stop sign. Took off from stop normally, not really jumping it at all and the SES light came on.

Peake codes are now:
C4 - misfire cylinder 1
C5 - misfire cylinder 3
CC - misfire multiple cylinders

Neither cylinder was in the previous code errors (was C5, misfire cylinder 2).

Where should I go from here as this seems to just be jumping around...
 

·
Registered
Joined
·
282 Posts
Discussion Starter #15
OK. So more to the puzzle.

I scanned with my standard OBD tool today. I got:
P1343 - Misfire cylinder 1 with fuel cut off
P1357 - Misfire cylinder 8 with fuel cut off
P1341 - Multiple misfire with fuel cut off.

Here is where I could use some input. In both cases where the SES light came on I was making, or had just completed, a right hand turn when the SES light appeared. First time happened entering the freeway on a long right hand sweeping on ramp. Second time, turning right from a stop sign. In both cases, the SES light goes away after a short period of time and performance returns. And there is a link to this issue from the past! In searching the posts by the previous owner, Alan A, I found this: http://www.m5board.com/vbulletin/e3.../12313-very-weird-problem-check-engine-4.html where he describes the same sort of circumstance. The car was damn near new at the time.

I went back through the service records and I see where he took the car to the dealership and they could not replicate the problem. I also saw at least two other SES complaints in the records when taken to a indy shop and they couldn't replicate the problem.

SO... Is it conceivable or probable that it is a fuel delivery problem? Possibly fuel pump or fuel sender related? Or a ground that is lost under heavy cornering??

I don't want to just randomly start replacing parts. So recommended testing, hypotheses and possible solutions are welcome!
 

·
Registered
Joined
·
4,488 Posts
It is not clear from your two posts if you cleared the Peake codes you read yesterday and the codes read today were new? Or are the Peake reader and OBDII reader interpreting the same codes differently?

And is the C5 code in yesterday's post a typo because C5 is cyl 2 but you list cylinder 3?
 

·
Registered
Joined
·
282 Posts
Discussion Starter #17 (Edited)
C5 was from the first time that this occurred about a week ago. Those codes were cleared.

C4, C6 and CC were pulled on the second occurrence as were the P1343, 1357 and 1341. I had not reset, just reread with the OBDII to see what it came up with. It did interpret the code differently (cyl 8 instead of cyl 3). dont know why. Also, OBDII notes as "with fuel cutoff".
 

·
Registered
Joined
·
10,307 Posts
I think you hit the nail on the head. It sure seems like fuel delivery to me. Not the delivery to the engine but the delivery to the cup in the fuel tank. How old is the fuel filter? How many liters per min do you transfer from left tank to right tank on a fresh cold start? Think that is test 4 or 7? Do test 14 on the OBD have any codes ?
 

·
Registered
Joined
·
282 Posts
Discussion Starter #19
Thanks. I need to go through the records I have again to see if any of the parts of the fuel delivery system have been replaced. I am thinking not because as far as I can tell this problem has been reoccurring its whole life. Also, I am just now learning about the secret menu. I will access today and report my findings.

I have been searching a lot on this misfire with fuel cut off. I have seen people reporting all kinds of different solutions that worked for them. I've seen everything from fuel pump, fuel senders, spark plugs, coils, CPS (mine have been replaced withing last 20k), vanos, I've even seen someone report that they changed the battery and that fixed it.

Weird.
 

·
Registered
Joined
·
10,307 Posts
The right turn thing is the key and it has been reported before. It has been filter or siphon/transfer pump. First thing to check after the above is how much fuel is being returned.
Low flow would indicate the filter. BMW thinks they are life filters so the previous techs may have skipped this.
That can be done at the fuel reg by disconnecting the return line and adding another line to a catch can. The transfer rate from the secret menu should give you an indication of the siphon pump condition. There might be a leak or something out of place and even if the siphon pump is working well the fuel may not be getting returned to the cup just the tank. You may need to open the tank and see what is going on. You would want to be on low fuel so you can see if the cup is staying full.
 
1 - 20 of 32 Posts
Top