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stuck spark plug
Posted: Wed Nov 05, 2008 2:56 am
by parrot820
Hi All,
I recently acquired a 2003 R1150R with 36k miles.
I have no maintenance history for the bike.
I took it in to my local BMW shop for the 36k service this morning.
While talking with them later in the day to see how things were going, the service manager told me that the left spark plug is "semi permanently stuck".
I don't know the exact details (frozen, turns but doesn't come out, etc), but he did say the tech was worried about pulling too hard and pulling out the threads.
He said it's something that needs to be addressed in the future, which (to me) means it's 1- not going to cause a failure by leaving it like this and 2- it's going to be pricey to get the thing unwedged.
Has anyone here experienced this particular problem before? Is this something I could work on myself by applying patience and perhaps some wd-40 to help the plug loosen up? Do I need to stop riding the bike until this is resolved? Should I go ahead and have them keep the bike and get this resolved before picking it up?
This is a new one for me, so I'm really not sure what the best course of action is.
Thanks very much!
Patrick
Re: stuck spark plug
Posted: Wed Nov 05, 2008 3:17 am
by snowprick
parrot820 wrote:Hi All,
I recently acquired a 2003 R1150R with 36k miles.
I have no maintenance history for the bike.
I took it in to my local BMW shop for the 36k service this morning.
While talking with them later in the day to see how things were going, the service manager told me that the left spark plug is "semi permanently stuck".
I don't know the exact details (frozen, turns but doesn't come out, etc), but he did say the tech was worried about pulling too hard and pulling out the threads.
He said it's something that needs to be addressed in the future, which (to me) means it's 1- not going to cause a failure by leaving it like this and 2- it's going to be pricey to get the thing unwedged.
Has anyone here experienced this particular problem before? Is this something I could work on myself by applying patience and perhaps some wd-40 to help the plug loosen up? Do I need to stop riding the bike until this is resolved? Should I go ahead and have them keep the bike and get this resolved before picking it up?
This is a new one for me, so I'm really not sure what the best course of action is.
Thanks very much!
Patrick
Semi permanently is a new one on me! I would advise that you go to your dealership and ask to see the problem for yourself. Ask the mechanic to explain the problem and how he thinks this came about.
I can only assume that the plug has been cross threaded in which case it will have to be removed. In this case thread damage to the cylinder head may result. That being the case it is possible to repair the head with a Helicoil repair kit or similar. BMW would no doubt take the position that they will only repair by part replacement.
In the event that the head IS damaged in this way I would ask my dealer to remove it and then it could be taken to a shop of your choice for repair. Then ask the dealership to refit the head.
If the plug is just FROZEN then WD40 and the assistance of a pneumatic wrench may be called for however thread damage may also result.
Anything can be fixed, only cost is the driver. Go look for yourself and take it from there.
Good luck.

Re: stuck spark plug
Posted: Wed Nov 05, 2008 8:15 am
by towerworker
You didn't say if the stuck plug is the old plug or the one the dealer tried to install? If the latter then it's their responsibility for repair. If it's the old plug then I agree with snowprick in that the plug must come out and thread damage may be inevitable if it is cross threaded.
You can remove the plug as easily as them if it's simply too tight or cross threaded. It might be worth using another product in lieu of WD 40 as a penetrant. There are other products more suited to penetrating frozen bolts than WD 40. I don't know name brands right off but any auto parts store should have a selection. I would spray it very liberally and let it soak overnite and then when it's cool in the morning take a wrench to it.
Good luck!
Wayne
Re: stuck spark plug
Posted: Wed Nov 05, 2008 9:48 am
by OU812
I have seen the core of a plug blow out. That was easy to get out with an extractor. Your symptom needs a bit more information as stated in the previous replies. Hope it works out.

Re: stuck spark plug
Posted: Wed Nov 05, 2008 9:53 am
by Beemeridian
11
Re: stuck spark plug
Posted: Wed Nov 05, 2008 3:00 pm
by boxermania
The most probable cause is that the plug is "galled" onto the thread, this is a common occurrence when dealing with steel and aluminum threads. If the threads have to be repaired, the helicoil is one option, however, Timeserts is a better option as the threads are stronger than those on the Helicoil thread repair.
Because of the location of the thread I would suggest that you rely on a shop that is experienced on the installation of the thread savers, unless you have the experinece necesary to do it yourself.
Best of luck and let us know how you make out.....

Re: stuck spark plug
Posted: Thu Nov 06, 2008 2:53 am
by parrot820
No, I don't have the skillz to really do this.
Not yet, anway.
I did talk to the tech today who's been working on the bike and we've worked out a course of action.
It's basically what everyone here has been suggesting, so I very much appreciate the replies. They definitely helped me better understand the options before discussing it with the shop.
I'm going to pick it up tomorrow as-is, with the old plug still in it.
The guy they want working on this is on vacation, so once he's back I'll take it back in and have them remove the old plug. If it strips the threads, then they'll go the helicoil route. I'll mention to them the Timeserts option.
I'm also going to keep an eye out for a used cylinder head between now and then, just to have that option as well.
In any case, I feel much better about how this is going to be resolved, so thanks very much for all of your input!
Patrick
Re: stuck spark plug
Posted: Thu Nov 06, 2008 10:02 am
by awagnon
A young man was recently riding through this area on his way to California when his R1100RT just spit out the left spark plug. We have to assume it was over-torqued or cross threaded at some time. Anyway, a local independent BMW shop (Motorcycle Repair and Rendezvous in Salt Lake City) was able to put either a Helicoil or Timesert in and had him back on the road by noon. They were able to do the work with the cylinder head still on the bike by pressurizing the cyclinder. That way, any shavings created when they bored out the hole were blown out of the head. He was assured his bike is better than new now. Later got word he completed his journey to California and then back home in the east without further problems.
Re: stuck spark plug
Posted: Thu Nov 06, 2008 10:14 am
by owldaddy
They were able to do the work with the cylinder head still on the bike by pressurizing the cyclinder. That way, any shavings created when they bored out the hole were blown out of the head. He was assured his bike is better than new now.
I can attest to this technique, I used it once on a Honda 350 my brother bought used. turn the engine over to make sure the exhaust valve is open and the intake is closed, then use compressed air in the exhaust to pressurize the combustion chamber, the metal chips will come flying out while you tap the new threads. A helicoil was installed, we never had a problem with that plug again.
Don
Re: stuck spark plug
Posted: Thu Nov 06, 2008 10:18 am
by SLEDGE
Steel screwed into aluminum can sieze. I would think that it would be about 50%-50% that the threds would strip. When plugs are changed, in Al heads anti-sieze compouned must be used to avoid-eleminate this problem. Used to run into this problem from time to time when I worked in a VW service dep. in the early 70's.
Good Luck