E60I

Hey guys,

From almost every "cold start up", my SES light pops up as soon as the idle start settling down to the pre-setted idle speed (approximately 600 RPM). I can prevent it from happening if I step on the gas pedal and let it run between 900 to 1,500 RPM for first couple minutes. Without the SES indicating so, the misfire is hardly noticeable. Can anyone please tell me why this is happening and how can I fix it?

The problem became less consistent after I insulated one of three wires that are connected to the ignition coil harness. I thought it was a sure fix when the raw wire is no longer exposed.

Here are my questions:

1. If the insulator of the wire for the ignition hardness is only 97% sealed, can it still cause such misfire at cold start up?

2. How can I check to see if fuel injector #4 is not leaking while the car is turned off for hours? I took observations of the tail pipe for blue or black smoke at cold start up and see nothing unusual...

Any feedback is greatly appreciated!

Thanks!

tonyb635

Not sure what kind of e60 you have. Maybe post that and someone may be able to give you better input. I had the slight stumbling rough idle for a while a finally the CE light illuminated. I had a # 6 misfire. I replaced the spark plugs and swapped the #5 coil with #6 and all was ok. My plugs had about 45k on them with a JB4. Not sure how long you could get out of the the plugs.

E60I

Thanks, Tony!

It's a 2006 530i (N52).

Because the broken part of the wire is in such a tight spot, I think I will have to combine liquid tape, electrical tape and heat shrink tubing to keep it from falling apart by the high temperature of the engine. Can the wire of the ignition coil harness be that sensitive when it's not 100% sealed and insulated???

tonyb635

I'm not sure about the exposed wires. Is there a way to replace it, maybe back to a connector? I don't recall the wires specifically, but remember they were small. How did they become damaged? I would imagine that at any time the bare wire touches any metal you would have problems but I don't know if they would leak if you only use tape or if you would need a special type of material to coat the wire with.

E60I

Yes, the three wires are small, Tony. I must of tore it while struggling to disconnect it from the ignition coil. ...or maybe, I have engine termites that like to eat ignition coil harness wires.

I think this is the part: RealOEM.com BMW E60 530i Cable harness injection valve/ignition

It does not look easy to replace.

The misfire only cause the SES light to come on at each cold start up if I don't step on the gas pedal to raise the RPM to around 1,200 within the first two minutes. The car does to stumble or do anything noticeable. The preset idle speed looks pretty steady also.

tonyb635

Curious if you can read codes. Often they are stored even though the se or CE light is on. If there is a stored code and it points to the coil with the damaged wire it might be a good indication of a special coating on this wire and the integrity needed.

E60I

Each time when the SES light pops up (only on cold starts), my code reader/reset tool always show 20C29D0 (Misfire on cylinder 4).

The coating/insulator for the three thin wires do not look like anything special. Because the broken part of the wire insulator is in such a tight spot, it's really hard to see if the electrical tape and heat shrink tubing really covered it.

Next time, I will use liquid tape for that tight spot, and the other two aforementioned insulators to see if they will do the job. The electrical tape and liquid tape have melted before (due to the high temperature of the engine). It would be ineffective if I don't use the heat shrink tubing to keep them intact. Problem is, I have to use an oversized heat shrink tubing in order to slip it over the wire harness; and I don't think it can shrink to a tight fit like it should. I'll get around to it, eventually.

Thanks for your help, Tony.