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Frank.Ind

M60 only firing on one bank! any idea's?

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Hope someone can help with this...

So for some reason my M60 touring is only firing on the N/S bank. Unplugged the coils individually on that side and nothing. Pulling the coils on O/S bank changes engine note.

It happened initially about a month ago, I had driven it for a long run, parked it, then a few hours after I arrived, moved it a couple of feet and turned it off. Next day, fired up, but smelt very fuelly... as it got up to temp it got very lumpy, to the point I pulled over and called out mechanic. With him arriving and much scratching of head, it just sorted itself (the mech literally did nothing other than look confused)... and was subsequently fine. Now the same has happened again, (long run, few feet) only this time, no fixing itself...

I was unable to work on it this week, so it sat... today I start it, and initially sounds great, but once warm its on 4 cylinders... also had a look around and the N/S cat is cherry red over the last third so there could be a blockage, but the cats are 6 months and I think it more likely that its desperately trying to burn all the excess fuel...

Any help greatly appreciated?

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its the starting it and moving it 2 feet. Its flooded, the cold start mixture like on the M50's is very agressive and this sort of thing isn't good as this happens and they can be a right pig to get going afterwards. Rich running will kill cats also. Thats my thoughts possibly

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Thanks for the reply Bumbaclut that was my thought initially also. What gets me though is that the cold start today was on all 8, only when up to temp did it drop to 4... this I don't understand...

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Hmmm.

I have heard of this kind of problem before. Two things. Firstly the starting and shutting down of the motor is never a good idea on a bmw of this era. I'd sooner drive it round the block and get some heat into it. However it doesn't sound like you've started the engine from a cold-cold situation,more a cold-warm scenario.

Secondly, I believe you possibly could have an ecu or loom fault. If it starts and runs on all eight and gradually loses four on one bank and the cat is glowing on that side it's pointing towards a fueling issue,more than likely running lean imp. It turned out in a previous case that the fueling stage in the ecu had failed for that particular bank on the normal running map. An ecu swap did cure it only for it to reoccur some time later and in the end that particular car was scrapped.

Have a look at the ecu. There may be external water damage or if your confident enough,open it and have a look at the PCB. Again look for water damage or maybe a dry solder joint if your lucky,which is quite possible.

If it is running lean,then you run a high risk of holing a piston or some other disaster. Of course it could be something else fairly simple or even a broken wire in the loom,but I have definitely heard that the control units can give issue.

Worth a look in this case.

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Thanks for your thoughts FIVE-OH. Although the glowing cat and smell of fuel to me points to rich running.

Either or, it's currently academic, as (touch wood) it's currently running ok. Did the "magic reset" and cleaned up the contacts on the N/S CPS (will be replacing both as a matter of course, as neither are looking great).

Restarted her, and get up to temp. Then as all 8 seemed to do what they were told, took it out for a run in a mix of city and motorway driving. SEEMS to be running fine (famous last words)

This points to a sensor issue to me (possibility CPS, but not discounting anything). But how it happened on both occasions suggests flooding...

Shall keep this updated, as there seemed to be a few people with this issue, with what seemed like no resolution.

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Ok great, some good news then.

When you say CPS, are you referring to the crank or cams? It may well just be a serious bout of flooding,something you can avoid in future. A faulty lambda could also have a bearing, but yes unburnt fuel burning in the exhaust/cat appears to be your problem.

Cold restart has been a problem for many a year on various bmw models, it's simply best to let the motor get to temp and off the cold cycle before shutting off.

Keep us updated on your progress.

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its the starting it and moving it 2 feet. Its flooded, the cold start mixture like on the M50's is very agressive and this sort of thing isn't good as this happens and they can be a right pig to get going afterwards. Rich running will kill cats also. Thats my thoughts possibly

I keep getting eyes rolled at me from my Girlfriend and/or my mother whenever I either refuse to move the car off the driveway and say to use my car instead for a short trip. Or I take the car on a quick drive upto temp when I concede to moving it.

It only becoming an issue once warm and the car sometimes starting on the full 8 sounds like the flood has damaged something that is negated by the 'choke' on cold start.

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Friend recently had this issue... No error codes, etc so it was a bit of a process to get it sorted.

 

His ended up being fixed rectifying the following issues:

 

Swapped the DME

Swapped the cam angle sensor

Corrected the O2 sensor wiring as they were plugged into the incorrect plugs on the loom

 

Swapping the DME seemed to fix it, but it would still happen intermittently which pointed to the CPS being faulty after some research, but we then noticed that the oxy sensors were plugged in incorrectly which also probably had something to do it with it at some point... 

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the O2 sensor got me thinking, i had an issue on my 6 pot e36 after i had done a head rebuild. The car ran perfect from cold, then started to misfire run like shit. Turned out i had the O2 sensors plugged in the wrong way round. As one sensor did cylinders 1,2,3 and the other 4,5,6. No fault codes either, So the fueling was all the wrong way round hence the running fault but the ECU on the cold start ignores the O2 sensor readings at first hence the nice running on initial start up. So i think i'd rule that out in your case? I assume the V8's have a sensor for each bank, so would give a similar fault if so. Normally a buggered 02 sensor plays up with more poor performance and high fuel consumption

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Hi, 

 

Hope you are well, 

 

i know this was a while ago, 

 

but I am experiencing similar issues, please could you confirm which o2 sensor is plugged into which connector?

 

is it the right sensor into right connector? And left into left? 

 

Thank you! 

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On 01/12/2015 at 13:03, t.wak said:

Friend recently had this issue... No error codes, etc so it was a bit of a process to get it sorted.

 

His ended up being fixed rectifying the following issues:

 

Swapped the DME

Swapped the cam angle sensor

Corrected the O2 sensor wiring as they were plugged into the incorrect plugs on the loom

 

Swapping the DME seemed to fix it, but it would still happen intermittently which pointed to the CPS being faulty after some research, but we then noticed that the oxy sensors were plugged in incorrectly which also probably had something to do it with it at some point... 

 

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Yes, pretty obvious if it hasn't been played with. My friend's car had been manual swapped and the loom wasn't layed correctly which led to the error.

 

I had this issue 6 months ago on my car, I changed the cam sensor for a genuine one which didn't fix it, so I then replaced the oxy sensors which fixed it.

 

Aden 

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On 21/05/2019 at 05:08, t.wak said:

Yes, pretty obvious if it hasn't been played with. My friend's car had been manual swapped and the loom wasn't layed correctly which led to the error.

 

I had this issue 6 months ago on my car, I changed the cam sensor for a genuine one which didn't fix it, so I then replaced the oxy sensors which fixed it.

 

Aden 

 

 

Thank you for the reply, 

 

ive got the same issue! 

 

I have changed the o2 sensors, same issue, then changed the camshaft sensor and got the same issues, - when I reset the ecu (disconnecting the battery for a while) all is fine - not sure what else to do.. next step is ecu replacement? 

 

Thanks, 

 

Kind regards, 

 

 

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