Xoutpost.com - Random M54 Misfire on Random Cold Start checklist...PROBABLY SOLVED

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- - Random M54 Misfire on Random Cold Start checklist...PROBABLY SOLVED (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/102116-random-m54-misfire-random-cold-start-checklist-probably-solved.html)

Quote:

Originally Posted by Ricky Bobby (Post 1073582)

^What do you think is adequate time then, say perhaps a few mins of idle each time if I am just washing the car? I'm leaning towards that as well, and glad the E34 has something similar. I don't think its a defect or faulty part its just a byproduct of the short time it is started up a couple times, by the time I go to drive it, there is excess unburnt fuel.

I know if the injectors were leaking down i'd smell fuel vapor or so I've read - plus it would happen more often.

It'more of a problem in the winter time because the car is using a premapped fuel ratio when it is in open loop and if you know anything about engine, when an engine is really cold it need a richer mixture to start and stay running. Older cars had a choke system. Newer cars with fuel injection either have a car start valve like my PORSCHE or the DME will command the injectors to stay open longer.

UPDATE: Brought my DIS Laptop to work today - here are the codes found - as they read verbatim on DIS:

F3 DME - Misfire, Cylinder 6
Combustion Miss with Cylinder Cutout (P1353 or P0306)
-Fault is relevant to Exhaust Gas
-Fault Filtered
-Fault currently not present
-Sporadic Fault

INSTRUMENT - C7 IKE - Tank Sensor 1 (fuel pump side)

Cleared them all and all gone except for this code (which I figured as it was a sporadic fault)

1E IHKA - Auxilary Water Pump - Short Circuit to Positive
-Currently Present
-Fault Frequency 255

So troubleshooting wise should I look at the following?
-Fuel pump (isn't the tank sensor on the actual fuel pump?)
-Check Cylinder 6 plug to see if its dry, if dry, swap coil pack to another cylinder, wait till it comes back - if coated in oil, perform VCG + Vanos service? I'm at 85k miles but my factory VCG is 13 years old.

Anything else I'm missing? I may take to indy which will do compression test just to be sure nothing major - honestly the engine runs like a top and I've had this thread up for almost 6 months and its only happened 3 times

Quote:

Originally Posted by jfoj (Post 1073768)

I did not read the entire thread in detail, but came across a few things I wanted to comment on.

1. The I6 intake has 3 ports on the rear underside of the intake right near intake runner #6. Some of these ports have caps, some may be used for other things depending on the vehicle year and model. The vacuum caps split and leak and can do even fall off. HIGHLY recommend a good inspection and replacing all the vacuum caps on these ports. Your vehicle is 13 years old and the rubber parts typically last 8-10 years under the hood.

See this picture - Intake Manifold and Vacuum Caps - E46Fanatics

I definitely will tend to these for sure, I was planning on doing the 2 vaccuum hoses off the lower intake tube and the long vaccuum hose from the SAP to the manifold as well.

2. You mentioned battery needing to be charged. In case you were unaware, BMW has the DME trigger the coils multiple times. This is a "Multiple Spark Discharge" feature just like the aftermarket ignition modules under the name of MSD. When the cranking Voltage drops too low, as a power saving measure the DME will disable this MSD feature. So it is possible your problem is aggravated by a weak/low battery. It may not be "caused" buy a weak/low battery, just aggravated or triggered by this.

I may not have mentioned it but replaced with a new Bosch AGM battery in December, so it has happened with an older battery (lasted 4 years) and the new one, so in this case probably not my issue.

3. You mentioned washing the vehicle before this problem happened. 2 things come to mind. Not sure if the E53 is a problem like the E70 where water can leak at the rear of the hood due to cracked and improperly sealed plastic cowling but maybe water is getting into and around the injector/coil or other connections at the rear of the engine.
You may be onto something but I think you hit the nail on the head below.

The other MAJOR problem theses engines have is they EASILY flood if the engine is started and the vehicle is just moved a few car lengths without letting the engine warm up for 3-4 minutes or at least driving around the block. The cylinder walls can be washed down easily and if the battery is a bit low and the DME disables the MSD function, you can EASILY have misfiring on start up like you mentioned about 1/2 way through the thread.
I think this is what hit it on the head is that this weekend I literally started up cold, backed out of the garage, shut off probably at the 1 minute mark, then started up, pulled in garage, and probably under a minute shut it down again and didn't start up till Monday AM (my latest misfire)

4. Last but not least, the tank level sensor and problems at 1/4 of a tank. I replace the fuel pumps in these vehicles by year 10 at the latest. The BMW fuel pumps are KNOWN to go soft and also fail as the brushes wear out. Not 100% sure on the E53, but on the E46 you can get a fuel pump and sender assembly for a decent price and it is a good piece of mind to have a new fuel pump so you do not get stranded on the road. If your wife drives the vehicle often, do this before she gets stranded, otherwise you will have a new Silver Honda Oddessy Minivan in the driveway shortly after the X5 leaves her stranded.
I'm with you and its definitely on the to do list, I also have a new Mahle fuel filter ready to go. I want to do the fuel pump as I feel like i'm on borrowed time due to age and exposure to ethanol, and filter at the same time. Mileage has been good, but I have had some random problems where the OBC range would dip down and fuel light on, but the range would slowly increase more and I'd end up getting a lot more miles, so I think it should be done fairly soon. Wife doesnt drive it (she can't currently drive stick) but I do like to be sure my X is reliable.

I really appreciate you chiming in and helping!

Thanks for posting your problems. My e46 xi has started doing this a couple times this past winter. I have been reading so much stuff on e46f and thanks to jfoj, I think I got all of the answers in one post.

Quote:

Originally Posted by jfoj (Post 1073768)

If your wife drives the vehicle often, do this before she gets stranded, otherwise you will have a new Silver Honda Oddessy Minivan in the driveway shortly after the X5 leaves her stranded.

:rofl:

Looks like I'll be replacing a fuel pump shortly. My 01 is at 146k miles on the original pump.

RickyB, my bet is oil in the plug bore.

I keep a spare fuel pump handy, (this also ensures the problem will never happen!! murphy's law!) I had issues with mine cutting out etc, but I suspected that the level sensor wasn't working properly. I have a spare pump so mine will never fail me now! lol, at least its an easy re and re from the back seat! :)
If you do your VCG its an easy job, the old gasket goes hard as rock, and might be tough to get off without a chisel or exacto blade.
also, the spark plug holes have their own gaskets, my old ones left small washers on them. make sure you get the old ones off!. the vacuum lines around the back are brittle, and you should be careful when putting them back on! I was able to raise them up and hold them out of the way with masking tape so they didn't interfere with the new gasket!
while you have the valve cover off, you might want to spray some degreaser on the exhaust manifold heat shields. keep em clean and all!
good luck!
:cool:

Thanks guys! I'll be getting the vaccuum tubing and replacing the caps on the back of the intake manifold, as well as the entire run of vaccuum tube/hard line from the SAP to back of manifold as preventative. Also the vaccuum tube coming off the L connector on the lower intake elbow.

Will probably have time in the next day or two to pull #6 - would my VCG leak tell tale sign be oil on the coilpack or in the plug hole itself, or oil on the spark plug head once I remove it? I was thinking a wet plug, but wanted to be sure. If I do find a wet plug or see a leak at the back of the VCG, its also going to be rebuild the Vanos time as well :)

Also I know its pricey but I may do the fuel pump preventatively anyway, the original is 13 years old and I don't want it to get me stranded - would rather do it with the fuel filter (which I've had on my workbench since October) and have peace of mind for another 10+ years

Can you get a smoke test done anywhere near you. I know a guy in Farmindale LI that did it for me. Might a good idea to get this done before actually spending any on the parts canon.

Vacuum leak discovery is time consuming. One quick trick that works is tapping in a simple vacuum gauge off an unregulated vacuum port on the intake. With the engine idling, wiggle, spray carb cleaner, pull on all the rubber lines, hoses that are attached to see if there are any quick changes to the readings.
The 3.0 valve cover is a simple affair with LOTS of documentation on best practices. Hell that cover has been around for more than a few years now. Easy 2 hr project. The real challenge is the thoughts of "While your in there........"

The rough idle maybe nothing more than a fuel fouled plug that needs to come up to temp (600+) at the tip to begin to burn off the carbon fouling. Most plugs will "clear" themselves by bringing the RPMs to 2,500/3,000 a few times in neutral. Others require a hold at 3,000 for a minute or two to burn off all the fuel left in the combustion chamber. The miss firing may trigger a miss fire code which will clear after a few dozen starts or by using a code reader/clearer.