Misfires/CEL

[opihi5]

Recently my car has been misfiring and after 5 mins of driving would trigger a CEL. The car is almost undriveable because of the misfires so i replaced all the sparkplugs and the problem is still there. After reading the faults it is saying combustion error in cylinder 6. I switched the coil pack and it still says cylinder 6.
Could this be a fuel injector?
Not sure what to do...

[Jobe.]

If you swapped coils and the misfire stays on the same cylinder you will need to swap injectors. If the misfire stays on the same cylinder then next will be a compression test and leak down test.

[yidgyi]

Swap injectors. I've done what you did so far but my issue for cyl. 5 was a faulty injector. I've had a BMW tech tell me its not rare to see a faulty injector or two on the s65.

[opihi5]

Originally Posted by Jobe.

If you swapped coils and the misfire stays on the same cylinder you will need to swap injectors. If the misfire stays on the same cylinder then next will be a compression test and leak down test.

Ill try to swap the injectors and see what happens. Cylinder 6 is second one up on right side if you were looking in the engine correct?

[Jobe.]

Originally Posted by opihi5

Ill try to swap the injectors and see what happens. Cylinder 6 is second one up on right side if you were looking in the engine correct?

correct

[Scharbag]

This is a helpful little animation.

[opihi5]

UPDATE:

Had my injectors flow tested and they are all good. Every sparkplug is replaced. Just put new o2 sensors in.

My car will start and idle fine, even rev. As soon as i put it in gear i get reduced power and a cel. Cylinder 6 is still showing a combustion error code.

Car has 30k miles
No idea what to do.
Any ideas?

[schnell1982]

Originally Posted by opihi5

UPDATE:

Had my injectors flow tested and they are all good. Every sparkplug is replaced. Just put new o2 sensors in.

My car will start and idle fine, even rev. As soon as i put it in gear i get reduced power and a cel. Cylinder 6 is still showing a combustion error code.

No idea what to do.
Any ideas?

Do a compression test.

[opihi5]

Originally Posted by schnell1982

Do a compression test.

Why would my car have low compression at 30k miles? I’m hoping my engine isn’t toast

[yidgyi]

I've heard of valves dropping. That was a diagnoses a shop thought was going on with my car. It's not common but it can happen.

I'd buy a new injector for Cyl. 6 and try that instead of relying on the flow test. My injector did a flow test and it came up fine the first time which led to more time trying to find the issue. Shop redid the flow test again and the reason why it didn't fail the first test was because it was on its way out. Do a compression test first though. If numbers are fine across the board try a brand new injector in cyl. 6 or move it to cyl. 5 thats right next to it and easier to access and see if the error follows it.

Good luck and keep us posted!

[opihi5]

Originally Posted by yidgyi

I've heard of valves dropping. That was a diagnoses a shop thought was going on with my car. It's not common but it can happen.

I'd buy a new injector for Cyl. 6 and try that instead of relying on the flow test. My injector did a flow test and it came up fine the first time which led to more time trying to find the issue. Shop redid the flow test again and the reason why it didn't fail the first test was because it was on its way out. Do a compression test first though. If numbers are fine across the board try a brand new injector in cyl. 6 or move it to cyl. 5 thats right next to it and easier to access and see if the error follows it.

Good luck and keep us posted!

After the flow test I moved the cylinder 6 injector to the opposite bank and cylinder 6 is still the problem. What do you mean by the valves dropping?

[schnell1982]

Originally Posted by opihi5

After the flow test I moved the cylinder 6 injector to the opposite bank and cylinder 6 is still the problem. What do you mean by the valves dropping?

Stop throwing parts at the car.
A proper diagnostic would help narrow down the cause without having to purchase any parts.

Swap ignition coils and check spark plugs.
With the spark plugs out you can preform a compression test utilizing the time spent when you checked spark plugs.
If the compression test is good, then you can look at the fuel injectors and so on.
What type of diagnostic computer are you using ?
What is your exact fault(s) code being set ?

[opihi5]

Originally Posted by schnell1982

Stop throwing parts at the car.
A proper diagnostic would help narrow down the cause without having to purchase any parts.

Swap ignition coils and check spark plugs.
With the spark plugs out you can preform a compression test utilizing the time spent when you checked spark plugs.
If the compression test is good, then you can look at the fuel injectors and so on.
What type of diagnostic computer are you using ?
What is your exact fault(s) code being set ?

2B3A
2B57
2796

I used inpa and Carly for diagnostic. These are hard codes that come back immediatley. I’ll have to have a shop compression test and check to see if the valves are good.

If anyone has experienced a broken valve spring let me know if your situation sounds similar to mine.

[bvrider1]

What ever came out of this OP?

[opihi5]

Originally Posted by bvrider1

What ever came out of this OP?

Advanced fuel dynamics kit failed and caused all of this. I'm now on gintani e85 tune and its good.

[M3 Number 86]

so it was just a tune??