SES Light On.... Misfire? [help from the pros please]

[Tleong]

I hate to say this.... but no one knows a clear answer to this. Amongst other future problems that could occur... I've been very tempted to get rid of the X.

[StanF18]

Originally Posted by mrbmwx5

Ohoh Time for new X5M.

Might need a better excuse for CEO X5//M approval than a cylinder misfire. Perhaps I can tell her the tranny is starting to go....

[StanF18]

Originally Posted by StanF18

Hey Simon, Mike, Weasel, TLeong:

I would like to proudly join this "E53 Mis-fire Club" as of yesterday, 4:58 PM, Eastern Time.

Thermometer showed 29F, not what I would call inordinately cold. However my 2006 4.4i begged to differ, and gave me quite the scare when I turned the ignition. Substantial bucking and stuttering of the front end, with a flashing "Service Engine Soon" light. Naively I hoped against hope that this would stop as the X warmed up, but it continued for the next 2 minutes. I put it in Drive and slowly rolled about 100 feet. Problem was not going away! I stopped, put it in "Park" and turned off the engine. I waited a good 30-40 seconds in the gloomy silence. Turned the ignition back on, and everything was back to normal. No bucking. No engine light.

Everything went well today also.

Weasel, assuming this is a 1-time deal, any possibility that engine can be damaged somehow during that 2-minute nightmare? Is this only an E53 thing, or does it happen periodically on other Bimmers? And finally, any action I need to take after the fact, or just pretend like it was a bad one-time deal?

UPDATE: Problem has not recurred. Had it in the dealership for an unrelated maintenance, and the SA ran the code history. They confirmed the mis-fire and said it is a "no action" item.

Let's see how the rest of the winter goes....

[StanF18]

UPDATE 2: OK, spoke to soon

Problem is back. Had another mis-fire at 18 degrees F! The usual shaking and bucking up and down.

Had to turn her off and re-start. She started OK the second time, but now the SES light is lit up all the time. Steady light. How much $$damage$$ are we talking assuming it's the oil separator? Will the $tealer take an arm and a leg?

[pochiserna]

Something similar happened to me. I was driving and it was around 32F here in Texas when the SES light came on. Later that day I got the code read and it was P0171 mixture too lean code. The light was on for the rest of that day but was gone by next morning when it warmed up. The SES light came back on again a few days later when the tempature dropped to around 35-36F but again went away when it warmed up later that day. I did not get any of the "shaking" symptoms that some describe and did not notice anything unusual about how the X was behaving but am wondering if there is anything I should check and or replace.

Do i have a vacum leak? Why would the light go away on it's own if there is something wrong? Thoughts?

[jst2878]

i believe the oil seperator has frozen up and you probably have a decent amount of oil hitting the sparkplugs. who knows, just take the car off the road in the winter like I do...it saves headaches and the x is more fun to drive once you get it back on the road

[m5james]

Vacuum leaks and OSV's don't fix themselves brotha. Around 100k miles, it's time to remove the entire intake manifold, valve covers and start replacing all gaskets in between. I got my pre-VANOS intake manifold chemically cleaned and degreased last week and ready for the upgrade/swap, just waiting for the snow to disappear this spring so I can do the entire cooling and intake system rebuild.

[Weasel]

So James, what is the difference again between the pre-vanos and post vanos intakes? Is it bigger runners like the M50 intake on an M52?

[m5james]

Exactly the same thing $$Dinan$$ didn't ever sell an intake manifold for the pre-VANOS motor (my 98 7 for example) so after a while we figured out that they were doing nothing more than reselling a stock BMW intake manifold. Ironically they sell ther factory intake manifold for $1200, which is still a markup over the dealerships price. I haven't 100% confirmed how it's done yet, but the pre-VANOS MAF (another popular 3 series mod) is also large than the VANOS version, and I've heard that simply swapping the sensor between the two different MAF's is the same thing as buying $$Dinan$$'s hi flow $400 aluminum version.

Your 4.6 actually already has this manifold RealOEM.com Part Cross-reference, while the 4.8 uses something completely different, so this is only for us 4.4 guys. Basically any manifold from a pre-VANOS V8 4.0-4.4 (3.5 maybe) can use this manifold on their M62TUB44 as a direct swap.

EDIT - Cancel the 3.5, it's the same as the stock current version currently used on the VANOS motors RealOEM.com Part Cross-reference

[JohnD]

This sounds like the cam sensor to me. I had this happen a few times in the past. It would always clear by shutting the car off and starting again. I drove it like this for a few thousand miles before replacing them