Misfire on cyl 2

[board]

Jumped in the car today to nip out and was running really rough so cancelled nipping out and got the computer out.

Found that cyl 2 was not firing according to the diags so decided to lift the cover to inspect what was going on. The car was serviced a few weeks ago and hasn't done many miles since, on lifting the cover I was greeted with this:


Which shows the number 2 lead was not put back in its cable tray and has subsequently been crushed by the cover. I have swapped number 1 and 2 coil packs round, cleared the codes, in order to double check those and the error remains on number 2. The plug is nice and clean.

My question is, does anyone know if it is possible to replace the lead without replacing the whole harness as from the little inspection I did it does not look like a simple unplug old and plugin new?

I can only think that this is the issue unless anyone has any other suggestions?

Thanks,
James

 

[badman gee]

Hello james.

I take it that that area of the car wasn't touched during the recent service?

I'm not sure if the cables are individual or part of a loom.

 

[board]

Inspection I, so they should have had it apart for the new plugs. I'm going to be calling them first thing to have a chat but trying to find out what the damage is likely to be, I don't know how sensitive the cables are but suspect they don't do too well with being squashed with the cover.

 

[badman gee]

Well it's possibly down to them.

No other reason for it to be trapped.

 

[board]

I'm hoping the cables can be replaced individually but I have a horrible feeling they can't and that's going to be expensive, I will have to see what the guy says tomorrow. Sod's law I have a long journey Tuesday and need the car.

 

[badman gee]

Good luck james.

 

[t-tony]

James, it may be possible to solder in a new piece of cable for the ignition coil with connector, rather than having to replace the whole lead set or loom.Repair sections may even be available from BMW?

 

[board]

I'm hoping that is the case, not having had one apart before I have no idea how they are connected.

 

[t-tony]

Good luck with it. If I can help pm me.

 

[board]

Thanks Tony and Mark, I'll let you know how I get on tomorrow. I just checked and the car has done 1035 miles since the service. I guess the compression from the heating and cooling damaged the lead.

 

[badman gee]

Keep us updated sir

 

[board]

Update. The service guys very kindly came out at short notice and had a good look round. We tested everything and it turned out with his computer that cyl 6 was not firing. We swapped everything round and did a test on the spark using his computer but still nothing.

I have now done continuity tests back to the ECU and all 3 wires are getting continuity back so it is looking like and ECU fault

 

[t-tony]

Bad news there James. Hope it doesn't turn out expensive.

 

[board]

Thanks tony. Trying to find a way of getting it tested, I have had a name of loom doctor given to me who comes out with an oscilloscope but can't find any details. I haven't got a trailer to put it on to take anywhere so it's becoming a challenge.

 

[badman gee]

Hope you get it sorted james.

 

[board]

I'll get there, just annoying with this lovely weather and the one day I have a long drive ahead down some twisty roads and it decides not to play. The guys at the garage were excellent by the way, despite my thinking that it was something they had done and was not, they did not charge for the call out and were spot on while working on it.

 

[board]

I must add, this is the first time it has let me down in the 14 or 15 years I have owned the car so not complaining

 

[board]

Quick update.

Good news, back on the road

Turns out it was the ECU which had a fault so sent it off to http://www.the-ecu-doctor.co.uk/ who received the unit on Tuesday and had it back to me repaired on Friday. They pulled the info from it which showed the coil pack was failing on Cyl 6 which had in turn caused the issue with the ECU. So new coil packs were ordered, refitted the repaired ECU and now running perfectly again.

I am pleased to report a top service from the local garage (my initial grumble being an incorrect diagnosis, they would not let me pay for the call out even though it was my fault), the ecu doctor and sopers for getting the coil packs in next day for me.

 

[hard top]

Good news......