1m Missfire that BMW can't fix

[BarleyE92]

Hi all

I have a 1M, what a fantastic car, when it's working.

let me make a v.long story short so that i can try to get some help, and also get huge amounts of sympathy

I've owned the car for 3 months. It's been in a bmw dealership for almost 2 of those. It has a misfire under hard throttle, mainly in 3rd gear. Parts changed under warranty to no avail:

plugs
all coils
hpfp
all injectors
all injectors again
no carbon build up

bmw have been getting help from HQ, and running more advanced diagnosis equiptment in the car when they test it. It does throw codes, but i dont know them im afraid. I beleive the codes say to change the things listed above, which obviously hasn't helped.

The next step is a new ECU, which is on order from Germany. I have everything crossed that this will fix the problem.

One final thing: someone has bumped into her in the car park, so she's scratched too. BMW will fix this, but still hugely frustrating.

So, what do we think?!

Thanks all
Tom.

[octainejunkee]

Boost pipes are prone to cracking, is it possible it has a small crack that hasnt thrown a code but causes issues under full throttle?
What fuel are you using? super is advised ie v power or tesco 99ron.
Other than that i'm sure bmw will fix it. have they given you a courtesy car in the mean time?

[BarleyE92]

Thanks for the reply. V power 90% of the time.

They have arranged courtesy yes. BMW have in general been extremely helpful, but it seems this one has them stumped.

thanks for the boost pipe shout!

[eeghie]

Bummer; Mis- and/or undiagnosed engine problems are on everyone's nightmare list, so hope you get it cleared up soon.

Can't hurt to check boost pipe, particularly if multiple/all cylinders are involved. Do you notice any performance dip, abnormal sound or vibration before or at the time of the misfire/CEL? Can you tell if it's a single or a series of misfire(s), the repairs done so far seem to indicate multiple cylinders are involved. Is limp mode triggered?

If not resolved by the new ECU and if it's a single cylinder that misfires: check the cylinder compression to confirm valves are properly closing.

It would not hurt to collect the error codes from the dealer and share them on here, (fi to confirm if multiple cylinders are indeed indicated in the error-codes).

Have you had contact with previous owner on this or the car's service history? Will your national BMW organization disclose previous service records?

Good luck!

[BarleyE92]

thanks for the great reply.

The dealer is going to double check the boost pipe, it would be great if it was something so simple.

The performance dips immensely. Once the issue comes on, any more than 5% throttle results in aggressive shuddering through the car because the mis is so bad. Turning the car off and back on improves performance for about 1-2 decent pulls, then the issue comes back.

No abnormal sound other than the mis.

Compression checks have been done, no issues found.

the previous owner assures me that the car never skipped a beat when he owned it. As it's still under warranty there's not a lot more he can do. Some digging has revealed that he runs a tuning company, perhaps it has been tinkered with, although he assures me that it hasn't. Full BMW service history inc running in service.

Thank you again, i want my car back!!

[eeghie]

Mostly based on 1-2 decent pulls after every re-start: my 'resolve' bet would be on the fresh new ECU. (Owning a tuning company and resisting to boost the addictive 1M torque 'high' is super human after all )

keep us posted!

[h-manuk]

Hi mate, Ive come across a lot of 1M's in the UK, tuned and non-tuned. PM me and I might be able to tell you if I know about your car!

[The Wind Breezes]

It sounds like you may possibly have an issue with something in your valvetrain that is only triggered under certain conditions.

The ECU is also a possible culprit. And any 1M owned by the owner of a tuning shop is guaranteed to have at one point been modified with a flash / piggyback minimum.

[BarleyE92]

Thanks to everyone for the replies. Thank goodness for the BMW warranty.

The new ECU is coming from Germany, and should be here later this week. I'll update again after they've fitted and tested this.

[e82m_van]

My CEL light came on today as I was speeding down the ramp on to the highway.
Car started sputtering and lost power immediately (and kinda sounded like a Subaru.. which I liked? )
I drove cautiously to the next exit and pulled over and checked the code on the vent gauge.

29cd = cylinder 1 misfire.

I turned off the car and started it back up, and all was well.
Car sounded fine and power was back.
I went back on the highway and tested to see if the problem will come back.
And it didn't..

Good thing I have extended warranty. I'll be bringing it in next week.

[octainejunkee]

Originally Posted by e82m_van

My CEL light came on today as I was speeding down the ramp on to the highway.
Car started sputtering and lost power immediately (and kinda sounded like a Subaru.. which I liked? )
I drove cautiously to the next exit and pulled over and checked the code on the vent gauge.

29cd = cylinder 1 misfire.

I turned off the car and started it back up, and all was well.
Car sounded fine and power was back.
I went back on the highway and tested to see if the problem will come back.
And it didn't..

Good thing I have extended warranty. I'll be bringing it in next week.

Most likely coil pack is on its way out, or poor quality fuel..

[heist_tub]

I shall solve your issue, straight trade for my bullet proof (lmao!) 135i. You're welcome

[BarleyE92]

Hi all, update:

the new ECU made no difference. A new engine loom is on order from Germany. Going out of my mind!!!

[mrphil]

Oh man please keep us updated

[Dackelone]

My bets are on a bad HPFP or your turbos(wastegates). Could also be carbon build up on the valves.

Are you sure they used the correct spark plugs? The N54T use different plugs than N55's.

[eeghie]

Originally Posted by BarleyE92

Hi all, update:

The new ECU made no difference. A new engine loom is on order from Germany. Going out of my mind!!!

Is the earlier observation of 1-2 decent pulls after restart of the engine, before the misfires occur still valid? If so, I have little hope for the loom as root cause. There's very little in the analogue realm that behaves (fails) in that way, even electronic gremlins (moisture etc) aren't that predictable.

Found out about the error codes?

[BarleyE92]

I've asked BM if they've double checked the above points, thank you both for posting.

The HPFP has been changed for sure, but not sure about the wastegates. Carbon build up has been checked and eliminated.

[e82m_van]

Originally Posted by Dackelone

My bets are on a bad HPFP or your turbos(wastegates). Could also be carbon build up on the valves.

Are you sure they used the correct spark plugs? The N54T use different plugs than N55's.

Not trying to thread jack or anything...
But I brought my car in for service today due to cylinder 1 misfire and they diagnosed it as carbon build up.. Which the extended warranty doesn't cover.
My car is currently at 47000km
Is it possible? Can I really have that much carbon build up?
I thought I didn't have too much milage on my car to have that much carbon build up yet.
Also I always use Chevron 94 (Which some says it worse than Shell but that's open for debate )

Thanks.

[BarleyE92]

Originally Posted by e82m_van

Not trying to thread jack or anything...
But I brought my car in for service today due to cylinder 1 misfire and they diagnosed it as carbon build up.. Which the extended warranty doesn't cover.
My car is currently at 47000km
Is it possible? Can I really have that much carbon build up?
I thought I didn't have too much milage on my car to have that much carbon build up yet.
Also I always use Chevron 94 (Which some says it worse than Shell but that's open for debate )

Thanks.

Yes, easily. Did they take pictures when they pinpointed that as the issue? You can get carbon cleaned elsewhere, i think BMW are quite expensive for c.cleaning.

[e82m_van]

Originally Posted by BarleyE92

Yes, easily. Did they take pictures when they pinpointed that as the issue? You can get carbon cleaned elsewhere, i think BMW are quite expensive for c.cleaning.

Thanks for the reply!
They are taking the intake manifold off today to have a visual confirmation that it is indeed the carbon build up.
If it is carbon build up, they said $1300 for cleaning.
And I found someone else that can do walnut blasting for $450

[BarleyE92]

Update: the engine harness did not resolve the issue.

The car is being picked up by BMW HQ and taken to Farnborough to be worked on there.

[e82m_van]

Originally Posted by BarleyE92

Update: the engine harness did not resolve the issue.

The car is being picked up by BMW HQ and taken to Farnborough to be worked on there.

Update with my misfire

After authorizing more labour hour for the tech to do more diagnostics, they were able to rule out the carbon build up.
It appears that it's the fuel injectors that need to be replaced (which is covered by extended warranty!)

Since it's a third party extended warranty, my advisor advised me that I take the car home, and put all the stock parts back on in the engine bay before bringing the car back for the representative from the extended warranty place to comes and inspect the car.