Engine Pinking

[arrybash]

Further Update (4 weeks in the dealers now).

Dealers got the Left hand cylinder head of and I got a chance to have a look at it myself.

The secondary spark plug is not chocolate brown like I would expect but black suggesting its not combusting the fuel. Also there is a black shadow of carbon about 25mm wide right across the central area of the cylinder head.

The top of the piston has a lot of carbon build up for a bike that has only done 8,000 miles. The carbon also looks wet.

To me this looks like the secondary spark plug is not firing correctly and may point to what been suggested above i.e. the secondary coils breaking down.

Has anybody had the secondary spark plug out. What colour should it be?

I would post the photos on but I don't know how to upload them.

Regards

Chris

 

[mr badger]

Chris

It might be time to try another dealer/ I've heard several times, including on this thread, about the secondary coil issue.

It doesn't show on diagnostics and some dealers just can't go off script. Technicians v. mechanics.

 

[arrybash]

Its not the dealers problem. They are being instructed by BMW what to do direct.

However I have been telling them its an ignition problem but they don't appear to be suggesting it back to BM.

Everbody on this forum is suggesting its the secondary coils and it looks to me like the secondary plug is not firing. I think I will email my dealer with the photos I took and tell them my diagnosis and to forward my email to BMW.

I may start getting somewhere then.

Chris

 

[Pukmeister]

Diagnostics don't always show up failed coils/plugs as they are fine at low cylinder pressures but break down under load.

First try a new set of spark plugs, about £4 each.

If that doesn't fix it, then spend about £75 on a new lower stick coil and fix it yourself. Be aware that the LOWER stick coils are handed left or right so be sure to buy the right one. Takes 5 minutes to change. Coat in ACF 50 to protect before refitting the plastic cover, otherwise you'll need another new one in 2 years time.

If in doubt about this, undo and remove the lower plastic cover over the stick coils with a Torx driver and inspect the metal body under the thin rubber covering. My bet is that it is split wide open through rusting.

You can measure the resistance of the primary/secondaries across the stick coils, but they only have resistance in one direction so you may need to change polarity with your meter to get a reading, which is a few Ohms across primary and a few KOhms across secondary IIRC.

Been there, done that etc etc....

 

[Kremmen]

Never mind tearing the heads off ...hasn't anyone considered gaping the plugs, changing them or swapping port to starboard??... swapping the coils??.... Is this using a hammer to crack a nut.
I understand that the dealer has to take instruction from BM,but are the basics being totally overlooked here.

 

[TeaPig]

Further Update (4 weeks in the dealers now).

The top of the piston has a lot of carbon build up for a bike that has only done 8,000 miles. The carbon also looks wet.


Regards

Chris

You using much oil? The 'wet carbon' look could indicate this.

Moreover, if you are mixing oil mist with the fuel charge, the octane rating of the fuel will be reduced, possibly enough to induce pinking on that side alone

It's also worth considering that pinking can be caused by both the fuel pre-igniting because the octane rating is too low for the compression ratio/head design, or due to a hot spot within the combustion chamber such as caused by the wrong grade plug or burning carbon on the surfaces of the head/piston.

The previous posts referring to swapping components right-left is very sensible, but it seems you're well past that point

 

[arrybash]

Its not using a drop of oil. I have always used shell. When the problem started I changed over to shell V power thinking it may stop it but it didn't.

Swopping coils over etc seems logical to me but the dealer is being directed by BMW.

I suspect the dealers ploy is do what BMW say, BMW will then pick up a big bill from the dealer and eventually they will find its a simple problem like a coil failed.

In the meantime I am left without a bike.

All I can say is I am pleased not to be picking up the bill.

Chris

 

[Pukmeister]

Chris,
as you already stated, you aren't burning the fuel properly on one cylinder.

In the interests of getting your bike working and back to you, can't you suggest to the dealer that they could just 'borrow' a set of lower coils from a display bike to fit to your machine for testing, take it for a test ride, and see if things are better ??

If it doesn't cure the problem, they have lost nothing.

If it does cure it, they can either order new coils for you, or fit new coils to the display bike and bill either you or BMW for the ones they used.

 

[arrybash]

I have had these conversations with the dealer. They will not do anything without instructions from BMW HQ. Seemingly BMW HQ will not talk to me either, I am only allowed to speak with customer services.

All I can do now is send an Email to the dealer with the photos and my diagnosis and ask them to send it to BMW.

The only weight I can add which my get me somewhere are my proffessional engineering qualifications. They will be far higher than 99% of those employed in the BMW technical dept.

Chris

 

[Goose]

I have had these conversations with the dealer. They will not do anything without instructions from BMW HQ. Seemingly BMW HQ will not talk to me either, I am only allowed to speak with customer services.

All I can do now is send an Email to the dealer with the photos and my diagnosis and ask them to send it to BMW.

The only weight I can add which my get me somewhere are my proffessional engineering qualifications. They will be far higher than 99% of those employed in the BMW technical dept.

Chris

THIS is the same shit we're having........ letter's of demand had gotten us nowhere.... we keep getting the blank looks and having the OBD tests done must have produced some results because they refused to give us the printouts and when asked whether we could just look at them... they also refused saying it's got to go straight to BMW-AG

BMW know there's a problem... however in the bigger scheme of things, we are merely a couple of small irritations around the world. In fact my heavy letters addressed to about 15 different BMW departments in Germany... also came up empty... on emails I got read-receipts but no response and no answers........... seems these okes have learnt from the best..... the Politicians!

 

[Nice 'n' Fat]

If the dealer you bought the bike from is the repairing dealer I'd start proceedings against them to reject the bike ..... that should get BMW's attention

 

[Nice 'n' Fat]

A letter to their Dealer Principal would be a good start

 

[Goose]

A letter to their Dealer Principal would be a good start

We tried that.............. they are all in cahoots and the threats/letters and requests have as much use and chance as a fart in a perfume factory!

 

[Nice 'n' Fat]

Then start proceedings to reject all three of them back to the supplying dealer

 

[arrybash]

Eureka, finally got it back today and the pinking seems to have gone. except it now seems it wasn't actually pinking.

The dealer didn't do anything after replacing the head, he just went for a run and phoned me to say the 'pinking' had gone.

The dealers conclusion was it was the head gasket that had failed and the noise like glass/pinking I had heard coming from the left hand pot under load was obviously the head gasket under pressure.

Maybe it wasn't totally passing as there is no evidence of carbon on the mating surfaces. Maybe the gasket was partial passing causing the pressure to drop.

The dealer advised me he had never heard of the head gasket failing before, so he assumes it must have just been a faulty gasket.

Anyway I did 12 miles bringing it home and no sign of pinking at all.

A now pleased BMW owner having been bikeless (well 1 from 3 anyway) for 5 weeks.

Chris

 

[Nice 'n' Fat]

Well that's a result of sorts I suppose?

At least you've now got your bike back and the noise has gone so

 

[Goose]

I found that the pinking becomes extreme when placing the engine under load.... i.e riding uphill in say 3rd gear at around 2000 - 2500 rpm.
The pinking also becomes more noticable when the bike's loaded and the ambient temp is high..............

We're off the the Cederberg at 12pm today for the weekend.... so about 300km of dirt roads through mountain passes... with pillions. Temp is forecast at around 28deg C for Saturday and up to 36deg C for Sunday.. PERFECT pinking weather!

Will give feedback on both GSA's!



For those of you that are interested - this is one of the most amazing trips in SA... so if you are ever in the country to do an accessible ride.. this is it!
Attache dthe Mapsource file - nice to view the amazing Strata in Google Earth!

 

[Nice 'n' Fat]

I found that the pinking becomes extreme when placing the engine under load.... i.e riding uphill in say 3rd gear at around 2000 - 2500 rpm.
The pinking also becomes more noticable when the bike's loaded and the ambient temp is high..............

Have you tried a lower gear?

 

[arrybash]

Goo0sepilot,

Your pinking description is exactly what I experienced, maybe its not pinking at but the head gasket faulty.

Chris

 

[Pukmeister]

Detonation under load

It could well have been "pinking" due to a carbon build-up around the metal flame ring bonded/pressed onto the cylinder head gasket, which is where most carbon deposits occur due to the change in section. Hot intake air and a lean mixture with high load/cylinder pressures (and crap fuel) are ideal catalysts for pre-ignition/detonation.

Have you tried a fuel system additive (eg Redex, Wynns, STP, Forte Cleaner etc) in the fuel tank and then give the bike a good thrashing (AKA Italian Tune-Up) ?