SOLVED: 2003 X5, 3.0l, runs rough, reset on restart?

cmelkoni · #1 01-25-2017, 04:06 PM

Hello,

I know some of the symptoms I'm about to describe have been listed elsewhere in this forum, but I've been unable to find a description close to what I'm experiencing. If a solution is on another post, please feel free to direct me there.

Issue: Every so often, my X5 will run EXTREMELY rough, almost as if all cylinders are misfiring. No power, sputtering like crazy, etc. This only happens when the car is at idle and it doesn't matter if the car is warm or cold. It starts with a barely perceptible change in idle RPM then, upon stepping on the accelerator, the car sputters bad. Turning the ignition off, then right back on immediately solves the problem. Again, this always starts at an idle, not while driving. Example: I pull into a store parking lot the other day and sit with the car idling while checking my phone. RPM's drop from around 1000 to about 800 with a barely noticeable change in engine sound. I go to pull out and the engine is sputtering. I stop, shut the car off, and restart and everything is fine. The really strange part is the only code being thrown is a "Misfire, cylinder #2". Now, I've driven a car with 1 cylinder down before and it wasn't nearly as bad as what my X5 is doing. I can't believe that the sputtering that is happening is due to 1 cylinder misfiring, but I have been known to be wrong plenty of times before.

Here's what's been done recently: DISA valve rebuilt, spark plugs changed, intake boots and air filter checked. I just recently purchased this car and, when I changed the spark plugs, I saw evidence that someone had switched coils on Cylinder 1 & 2 in an effort to solve the issue.

Seems like an electrical problem over a vacuum issue because a restart of the car always fixes the problem.

Any help would be appreciated and, again, my apologies if this issue has been addressed elsewhere.

upallnight · #2 01-25-2017, 04:30 PM

Are your check engine or service engine soon lights working? There have been postings from other new X owners that reported that the previous owner has either tape over these light or remove them from the dash so that they wouldn't be illuminated when a perspective buyer came to look at the truck. Shutting down and restarting tells me that you have a misfire or several misfires that the DME/ECU has recorded and is shutting down the injector(s) to prevent damage to the cats. Restarting the engine just restart the misfire counter in the DME/ECU until it reaches a certain count and then it shuts the injector(s) again.

cmelkoni · #3 01-25-2017, 04:43 PM

Yes, SES light is working and that's how I knew to scan for the "Misfire, cylinder #2 code".

Interesting information. I didn't know the computer would shut down an injector after a certain number of misfires. Looks like my next step is to swap a coil pack with another cylinder and see if the issue follows the coil, which I should be able to do tonight.

Again, it seems to me that the sputtering is much more rough than what would be experienced with 1 cylinder out, but I don't have direct experience with this in an X5 and a straight 6 as this has.

Will post more after coil swap.

cmelkoni · #4 01-25-2017, 04:52 PM

Another question for you: Does the computer only shut the injector down after a certain amount of misfires AND only when the car is stopped? That would make sense from a safety standpoint and would further point to an actual issue in Cylinder #2.

ylwjacket · #5 01-25-2017, 05:32 PM

Quote:

Originally Posted by cmelkoni

Another question for you: Does the computer only shut the injector down after a certain amount of misfires AND only when the car is stopped? That would make sense from a safety standpoint and would further point to an actual issue in Cylinder #2.

I've no clue, but upallnight can probably answer.

upallnight · #6 01-25-2017, 08:17 PM

Quote:

Originally Posted by cmelkoni

Another question for you: Does the computer only shut the injector down after a certain amount of misfires AND only when the car is stopped? That would make sense from a safety standpoint and would further point to an actual issue in Cylinder #2.

The computer shuts down the injector only after a certain number of misfires has been recorded. The computer will shut down the injector even if the car is moving. When the injector is shut down, the computer will turn on the service engine light.

The counter is reset when the engine is turned off. The service engine soon light may go off when the engine is shut down and restarted but will come back on when the injector is turn off by the computer.

cmelkoni · #7 01-26-2017, 04:21 PM

upallnight,

Thanks for the information. I have never once had the X5 shut off the injector and run rough while driving. Every single time has been at idle. Once in driveway, twice at redlights, once at store, etc. Is it possible that the coil in cylinder #2 is only misfiring at low RPM's and thus hits the counter only when in idle? Have you ever seen this behavior before?

Picking up a new coil in an hour so this post may be moot, but it would still be great information to know.

ylwjacket · #8 01-25-2017, 04:51 PM

When a coil pack goes bad, you'd think the engine was going to shake itself out of the car. In addition to running really rough, there is a very noticeable drop in power.

It feels almost dangerous to drive. If you have a misfire code, it might be the coil. Cheap part, easy to swap out.

It is almost hard to believe how badly one bad coil can affect the performance.

upallnight · #9 01-26-2017, 05:56 PM

It would help if the poster would post all pertinent info when they post their problems. Nowhere in his first post did he posted that he had an SES light come on. That is why in my reply to his first post I asked him if he had a working SES or CEL light. That is when he replied that the SES light came on and he scanned it and came up with a misfire code. The more info that a poster can provide the more accurate a guess on our part. After all, we are not there to see, listen and perform rudimentary tests so any advice on our part is just an educated WAG (Wild Ass Guess).

cmelkoni · #10 01-30-2017, 04:37 PM

My apologies. I thought I had posted all pertinent information and had just assumed that describing the OBD code for cylnder #2 misfire implied that my SES light had come one. That was my fault.

Here's the latest update: I was so sure that this was a failing coil pack that I replaced the coil on Cylinder #2 on Friday. I then took a weekend trip and didn't even get out of the gas station before it happened again. Same thing as before, always when stopped and idling, never while driving. In this case, it happened twice, once while idling at gas station, second while idling at friends house after starting it to warm up. As before, idle drops slightly, can hear engine running different, SES light comes on. Step on accelerator and car is a shuddering mess with barely any power. Shut off ignition, turn back on, and car is back to normal.

A little more codes thrown this time though. Now I'm getting:
P0300: Random/multiple cylinder misfire detected
P0302: Cylinder 2 misfire detected
P0306: Cylinder 6 misfire detected

I also had a cylinder 5 misfire code before I erased them the first time. So, multiple cylinder misfires now instead of just cylinder 2. Really wish I had the other codes before I bought a new coil pack.

Now, I realize there are numerous issues that could cause random cylinder misfires: fuel delivery, vacuum leak, bad computer, etc. But, I'm hoping that these 2 symptoms can narrow down the list:

1. Only happens when idling and stopped. (Alternatively, it could be just at low RPM's for an extended period of time which is what idling is essentially)
2. Ignition off then on immediately solves the problem.

I would appreciate anymore insight someone could give.

Please let me know if you need more information and I will be happy to get/share.