One cylinder running faulty

[foxy2000]

Hello
I have a 2004 bike with 26000 miles on it. The last month it seems to be poorer with fuel consumption (150 miles to the full tank), is a bit juddery at low revs and when we took the coils and plugs of today, the left hand cylinder plugs are black and sooty, compared to the normal right hand ones. There is a spark at both plugs. We changed the plugs and the new ones started sooting up straight away. My BMW bike mechanic mate has had a quick luck and we are not sure what it is. Faulty coil? Faulty fuel injection?

It still runs generally ok. I use for daily 30 mile motorway commute and weekend rides.

Any help or suggestions appreciated.

Foxy

 

[VAL. H.]

Hello
I have a 2004 bike with 26000 miles on it. The last month it seems to be poorer with fuel consumption (150 miles to the full tank), is a bit juddery at low revs and when we took the coils and plugs of today, the left hand cylinder plugs are black and sooty, compared to the normal right hand ones. There is a spark at both plugs. We changed the plugs and the new ones started sooting up straight away. My BMW bike mechanic mate has had a quick luck and we are not sure what it is. Faulty coil? Faulty fuel injection?

It still runs generally ok. I use for daily 30 mile motorway commute and weekend rides.

Any help or suggestions appreciated.

Foxy

Get the bike down to your local BW dealer and ask them to plug it into their computor. It'll cost you about twenty quid.

They will be able to tell you exactly what is wrong and therefore save you a whole load of hassel trying to find out. you can then decide what to do about it.


There is a small possibility that you have a coil problem. But if the sooting of the plugs is definately 'both' plugs, it's probably something else.


HTH Val.

 

[Pukmeister]

Coils can seem fine when tested with a meter, but then break down when under load.

They aren't cheap, but they don't cost the earth either. The lower secondary coils under the heads are usually the first to go wrong due to exposed corrosion of the steel laminated cores.

 

[foxy2000]

Coils can seem fine when tested with a meter, but then break down when under load.

They aren't cheap, but they don't cost the earth either. The lower secondary coils under the heads are usually the first to go wrong due to exposed corrosion of the steel laminated cores.

Thanks both. We wondered if coils was the problem. Would a faulty one cause both plugs in that cylinder to look black (not just the one with the faulty coil)? Also noticed after a ride that this cylinder head feels cooler than the other one. Does that fit with a coil problem?

Foxy

 

[Deacon]

maybe this will help

Check this thread: http://www.bmwmoa.org/forum/showthread.php?t=29345&highlight=secondary+coils

 

[Pukmeister]

Could be coils, you have incomplete combustion. Could also be compression. Check your valve clearances, early bikes had a habit of breaking valves.

 

[foxy2000]

Thanks
Will try new coils and check valve clearances this weekend. Am needing to use it daily for work. Will it cause any significant damage to run it with one cylinder fouling up?

 

[WindyChuffer]

Have had similiar symptoms in the past; for me it was the throttle potentiometer / position sensor thingy. Cheap as chips even if it wasnt the warranty that was paying.

 

[bobtail]

hi foxy 2000 have had this problem on my gs 09 18000 miles was taken back to dealer rough idle low mpg found the problem was a lamber sensor on one downpipe causing the plugs to foul on that cylinder all sorted with new sensor

 

[foxy2000]

Seems it is the Lambda sensor. Didnt show up on diagnostics, but apparently they dont unless they are totally gone. However, when I swapped the sensors round today and ran it for a few miles, the plugs on the other side went black and the plugs on the other side returned to a healthy brown. Thanks for all suggestions.
Foxy

 

[Pukmeister]

Thanks for the feedback on your problem, it's one worth remembering.

 

[EggChaser]

Seems it is the Lambda sensor. Didnt show up on diagnostics, but apparently they dont unless they are totally gone. However, when I swapped the sensors round today and ran it for a few miles, the plugs on the other side went black and the plugs on the other side returned to a healthy brown. Thanks for all suggestions.
Foxy

Only just saw your message, mine did exactly the same a year ago (including confusing the dealer by not showing up on the diags)

Dealer did all the work swapping plugs, tps and coils from one side to the other until they found it.

 

[foxy2000]

Thanks for the feedback on your problem, it's one worth remembering.

Sadly its not over. Got a Lambda Sensor off Ebay. Fitted it. Plugs on both cylinders now looking healthy brown. Fuel economy improved. But, the bike is still misfiring / juddering for a few seconds when I open the throttle hard and generally is running a bit rough and occasionally cutting out when idling at lights. Seem sto have got worse since fitting the Lambda Sensor. Thought it might be the fuel pump controller, so have replaced that today. No change. Plugs have been changed recently. Getting fed up now. Could there be be a faulty coil still? If a coil, wouldn't the plugs look black on that side? Fuel pump? Fuel injection? Thinking of changing all the coils, but dont want to spend another few hundred quid on a guess. Any further help appreciated.

Foxy

 

[foxy2000]

Sorted. After all that, after talking to Bob at Motorworks, I replaced a main coil and it runs fine again. So it was a combination of lambda sensor and faulty coil. Thanks for all suggestions. Has been a useful learning curve.
Foxy

 

[Pukmeister]

Ironic that my bike has developed a similar problem, the RH lower stick coil practically melted and has been replaced but it still runs sooty on the RH cylinder, lumpy performance and poor MPG. If I can post a pic of the failed coil I will put it on here for reference.

Just ordered a replacement Lambda as my GS911 says the heating element within No 1 Cylinder lambda is not working, plus the O2 trace when plotted is all over the place for No 1 cylinder.

£69 for a new Lambda from an ebay seller (Or £140 from BMW if you insist on buying a box with a blue propeller containing the same item from NGK/NTK).

I shall use a shot of Redex at next refuel to give the soot deposits a burn off.

 

[trainman]

Sorted. After all that, after talking to Bob at Motorworks, I replaced a main coil and it runs fine again. So it was a combination of lambda sensor and faulty coil. Thanks for all suggestions. Has been a useful learning curve.
Foxy

i believe that an engine with incomplete combustion can cause damage to lambda sensors due to carbon deposits on the sensor head

so maybe not a co-incidence and anyone with coil failure should check or get checked the respective sensor to be sure

 

[Bobbyspit]

my mates 1150 did this earlier on this year, he had fitted some new lights and on trying to start the bike found it ran like crap.
It was running on one cylinder.
I had a look and checked the following,
1. spark at the plugs. Check
2. swopped the coils. Check both working.
3. removed injectors and checked. Working.

In the end I noticed the cable to his right hand side throttle body was sticking and that sorted same issue running like crap.

So removed the battery leads and left it 5 mins before re attaching, this sorted the problem. If that had not sorted it, we would have had to look at a dealer or Biker warehouse...

 

[rowbo99]

Here are some pictures of Pukmeister's failed coil - my healthy (although grubby) coil is on the left.

 

[ebbo]

Ironic that my bike has developed a similar problem, the RH lower stick coil practically melted and has been replaced but it still runs sooty on the RH cylinder, lumpy performance and poor MPG. If I can post a pic of the failed coil I will put it on here for reference.

Just ordered a replacement Lambda as my GS911 says the heating element within No 1 Cylinder lambda is not working, plus the O2 trace when plotted is all over the place for No 1 cylinder.

£69 for a new Lambda from an ebay seller (Or £140 from BMW if you insist on buying a box with a blue propeller containing the same item from NGK/NTK).

I shall use a shot of Redex at next refuel to give the soot deposits a burn off.

Hi Adam, can you post up your NGK part number for future reference please, cheers

 

[Pukmeister]

Will do once the part arrives. The website I am buying from clearly states the OEM part number for reference and also the overall length, plus it states the new Lambda has the correct plug on it for the BMW motorcycle fitment.

As you can see in the picture of my failed coil posted above (cheers Mark) it has oozed out some form of goo from within and also the grey end has melted and burst outwards. I presume it got pretty hot to do so, no wonder the bike was running like shit. I had to steal Marks good coil to ride back to Pompey from Glasgow, and ordered him a new lower right hand coil in lieu, coming via Germany as there were only two in the country, one at Park Lane and one at Chandlers Brighton. (unbelievable on a 14 grand bike sold in the thousands)