2005 K1200S Valve Cover Gasket Leak - Bolt issue???

[Bob-O]

Greetings.....
I'm new to this forum and it's possible this question has been covered before, but initially being a "guest" I found my searches somewhat limited. So here goes.....

I have a 2005 K1200S with approx 35K miles (yeah, I'm in the US).  Bike has been meticulously cared for, garage kept, not raced or abused.  I have a small leak at the lower valve cover.  I have found numerous references to the gasket being the (likely) culprit, but a respected parts/service guy here at a BMW dealership in my state said he has heard of an issue regarding the cylinder head and a bolt hole that was incorrectly drilled before tapped to the correct depth. The other head holes are correct. Thus when the gasket is applied and cover installed in the correct manor, this associated bolt in this hole will bottom but..... will give a positive torque "click" at 10Nm. However  in actuality the bolt is not compressing the gasket at this location the same as the other bolts.  Though the gasket appears to be sealed correctly and may run for years without any leaks; eventually as all gaskets do, a failure will occur. 

The same source also indicated that the first thing he would recommend would be to remove the bolt and shave off 1 - 1.5mm off the end, re-touch up the threads to be sure no burrs exist and the bolt threads smoothly into the head; to re-torque the bolt to 10Nm and see if the gasket continues to leak.  If the leaks continues, obviously replace the gasket.  I think the bolt modification couldn't hurt if I have to go through all the effort.  So the question is.... has anyone heard of this bolt issue before??

What are everyone's thoughts?

Best regards................  Bob-O

 

[armstrongracer]

Can't you just measure the depth of the hole add gasket plus valve cover thickness where the bolt sits and compare that with length of bolt from under head to the end. The first dimension should always be greater than the second.  Also, if there are supposed to be washers under the bolt heads, check that they have been fitted, and if so, check that they are the correct thickness.

[chriscanning]

Bob

The type of info you are talking about would be a factory update to a dealer and very unlikely available too the public, no doubt who ever told you has insider info but that is very rare.

I say the above...as once very well connected in the bike trade, particularly with a major BM dealer and when asking for help with an early K by a guy who contacted me I was sent a dealer update, which too my frustration lost in a computer change, but to say it was involved was an understatement....a mod that you early K may well have...but BM like to keep their cards very close to their chest because it’s bad PR letting the public know about such.

[Phmode]

Measure it, shave it a little, which can't do any harm and try it.

You should have full access to the search facility, even as a guest, but from my ailing and failing memory I'm sure Matt(?) had this on his K a while ago. Was it the same leak? Was it even Matt?

[farmer]

would a thicker washer not have the same effect?

[Matt]

Measure it, shave it a little, which can't do any harm and try it.

You should have full access to the search facility, even as a guest, but from my ailing and failing memory I'm sure Matt(?) had this on his K a while ago. Was it the same leak? Was it even Matt?

It was me yep! They just replaced the gasket. I feel like it was within 3k of a valve clearance check so I blame shoddy shoddy. But it could also neatly be explained by the OP's story. Though that's an early 12 so I'd hope they fixed that kind of hilarious oversight. Design of batch?

[Phmode]

Whichever way you 'solve' it, (short of drilling deeper - NNNOOOO, don't do that!) there is no guarantee it will last beyond a tech putting bolts in different holes. Unless you shorten all the bolts...

[farmer]

thicker washers would be the same as shortening all the bolts,

[Philip]

When I was investigating the poor running of the new to me, Matts old K1300S earlier this year, I did find the engine breather rubber pipes blocked.

There are 2 pipes at the rear right of the crankcase, just in front of the alternator that discharge into the air box.

I found both pretty well blocked with mayonnaise type oil crud.

This will result in increased crankcase pressure & may instigate a leak from the cam cover or any other gasket/ oil seal.

Might be worth checking those breather pipes as well.

[Phmode]

thicker washers would be the same as shortening all the bolts,

True but that means removing all the bolts with the risk of causing more weeps. Using a washer means 'someone' has to remember it there and where to put it on re-assembly.

[farmer]

you simply take out one bolt at a time put on a suitable washer and reinstall bolt, it's the simplest method for doing what your're trying to do, using a shorter bolt would be the same thing but still the same work involved.

[Bob-O]

Friends.... those are all great and timely responses. Thank you!  The owners knowledge base in these forums are extraordinary. At 35K miles it seems replacing the gasket makes the most sense considering what I have to take apart just to get at the cover. AND perhaps a slightly larger washer (IF) the bolt hole is different then the other three. Grind off too much material off the bolt and it will be back to the dealer for an extraordinarily over priced bolt.  Once I get a chance to tear it all apart to do this I will re-post with my measurements in case others find the same issue. 

Best regards.............  Bob-O

[Phmode]

you simply take out one bolt at a time put on a suitable washer and reinstall bolt, it's the simplest method for doing what your're trying to do, using a shorter bolt would be the same thing but still the same work involved.

I’ll try one more time. Leave a washer out (current, future , owner or dealer tech) and the leak comes back.
Shorten one bolt, swap the bolts, ditto.
Shortening all bolts is the only ‘foolproof’ way.

[TomL]

I would be surprised if the gasket was at fault because it is a moulded rubber everlasting type. I always refit the cover and gasket with a thin smear of silicon sealer on the face which goes up against the head.

[farmer]

i'm not trying one more time.