20150506 - Compression and Leak down test results (65,500 miles)

My K1600GT is burning oil at the rate of 400CC/1000 miles.  That doesn't sound like a lot, but that means 2.4L of oil between oil changes.

Part of the reason this concerns me so much is that I was initially a bad BMW owner and until I had my first oil episode, I never checked my oil.  The bike was under warranty, so I always just threw a leg over and rode.  Very soon after the bike hit 36,000 miles and was out of warranty, I got an oil indicator and found that I was low on oil.  I have been chasing this problem since.  The bike now has 65,500 miles on it.  The whole history of this is documented on this blog under the maintenance section.  Initially, I thought maybe the dealership didn't fill the oil all the way, but the problem was and still is recurring.  Of course, now I pay much closer attention to my oil levels, particularly on long trips.  I always have an extra quart in my side case.

After my last iron butt ride, I calculated the above oil loss rate and decided that the next best step forward is a leak down test.  I need to have confidence in my bike as I tend to ride it long distances and really want to push into areas further and further off the grid.  Since I'm doing my own maintenance now, I plan to add the leak down test to every 12,000-mile service.  As long as I have to get all the way down to the spark plugs anyway, I might as well do it.  For the initial test, I wanted the dealership to perform the test, particularly since I don't have the time right now to do an engine rebuild or even a valve replacement, should that have been the problem.

Without further delay, here are the results of the 65,500-mile leak down test on a 2013 K1600GT...

Compression:

#1 - 16.8 bar
#2 - 16.0 bar
#3 - 17.1 bar
#4 - 17.7 bar
#5 - 17.4 bar
#6 - 17.3 bar

Leak Down:

#1 - 10%
#2 - 10%
#3 - 10%
#4 - 10%
#5 - 10%
#6 - 10%
Good > 14 bar, Normal 12-14 bar, poor < 12 bar.


The dealer says all things are OK, but the 10% leak down seems borderline to me.  They buttoned up my bike before looking into this any further.  The next service I will be doing is at 72k.  When I repeat the test myself, I will be looking for any change and be listening to the exhaust, air intake, and crankcase for an indication of where the oil loss is.

Stay tuned.  More to come on this.