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Oil leak from cylinder head gasket after oil change

8.4K views 15 replies 8 participants last post by  ViperNC  
#1 ·
Recently, I changed the oil on the R NineT and soon thereafter I had a slight drip coming from the left hand cylinder head gasket at the bottom leading edge. After a few rides it appeared to be almost stopped completely so I thought maybe it was just pushing some synthetic oil past the seal under pressure. The last ride we took was about 200 miles and the leak was virtually gone, but almost a week later I have a drip on the floor. It only appears to be leaking when the bike is cold and stops when it heats up. Anyone run into this before?
 
#4 ·
Both posts above are spot-on. Please expand if it's the cam cover or the actual cylinder head gasket. Its a common thing to see confusion here.

Over-filling with oil can cause increased crank case pressure but IMO it would have to be seriously over-filled for that to happen. Easy to check though, and definitely worth it!
 
#5 · (Edited)
According to the diagram I just looked at it and I hope it is the cylinder head cover gasket. I used 4 quarts as instructed by the dealership so I don't believe it was overfilled and only switched to synthetic. Wonder if this will "cure itself" (unlikely) as the engine burns some oil or not? I guess the gasket is expanding when it is hot and then contracts when the bike is cold allowing for oil to seep by. Here is a photo:

Image
 
#6 ·
Hopefully that is just loose. That gasket is stupid expensive, about 4 times what they used to cost on the 05-09 models of the boxer. I'd start by removing the cylinder head cover and gasket, clean it up, insect it, then put it all back together again and torque as specified. Put down some rags or a used cookie sheet to catch the little bit of oil that will come out when you remove the cover.

Have you ever had this cover off before? Is the bike still under warranty?
 
#8 ·
In my world that’s a drip not a leak … a leak happens when oil is pushed out under pressure a drip is just something loose like a valve cover in your case. Make it easy on your self by first re-torquing the cover … ride it for a bit and check it again, chances are good it will have stopped. If not ..follow the advice of FSEngineer above and you’ll get it right … no biggie, just a drip on the shed floor. After all, although it is a BMW it’s still a motorcycle, I’ve had a bunch of them and all of them left a little oil on the floor now and again ….. part of the romance of being
UpOn2 ……..Blitz 🏍
 
#10 · (Edited)
You can check the oil level very easily in the inspection window... no need to guess ;)

The bolts that hold the cam cover on have a shank on them, so they bottom out on the head before crushing the rubber gasket too far. They just need to be nipped up enough to not come loose. Its very easy to over tighten them and shear them off, even using a torque wrench (threads are usually covered in oil which leads to over-torquing). I no longer use a torque wrench, I just use a "screw-driver" style handle and tighten them gently (The mech at my dealer recommended that and its worked fine for me for years now on my other boxers)

Take the cover off, clean up the surfaces and gasket with a cloth and re-assemble carefully, make sure everything is aligned and nip the bolts up gently. if it still leaks after that you may need a new gasket.

Torque Wrench @10Nm caused this on my 1200GS LC.
Image
 
#11 · (Edited)
Thanks for all the guidance. The oil level was fine and I did check to make sure I didn't overfill after changing the oil before the leak happened. I took the valve cover off today and found a bend in the gasket in the same area where the leak was occurring. I did my best to straighten the gasket out so it would lay completely flat and cleaned everything up:

Image


After putting everything back together and making sure the gasket was lined up properly, I cranked the bike and let it warm up to 205 degrees before shutting it off. Checked my oil level again after 15 minutes and the oil level is at 60% of the sight window so I would imagine it should be around 75% by tomorrow AM. So far (fingers crossed) everything is holding tight and dry. My guess at this point is the BMW motorcycle oil was not getting past that area of the gasket where the bend was, but switching to fully synthetic oil exposed the problem.

If it does leak again, I'm tempted to just get some RTV silicone and run a very thin bead on that area around the leak and be done with it.
 
#13 ·
Thanks for all the guidance. The oil level was fine and I did check to make sure I didn't overfill after changing the oil before the leak happened. I took the valve cover off today and found a bend in the gasket in the same area where the leak was occurring. I did my best to straighten the gasket out so it would lay completely flat and cleaned everything up:

View attachment 149293

After putting everything back together and making sure the gasket was lined up properly, I cranked the bike and let it warm up to 205 degrees before shutting it off. Checked my oil level again after 15 minutes and the oil level is at 60% of the sight window so I would imagine it should be around 75% by tomorrow AM. So far (fingers crossed) everything is holding tight and dry. My guess at this point is the BMW motorcycle oil was not getting past that area of the gasket where the bend was, but switching to fully synthetic oil exposed the problem.

If it does leak again, I'm tempted to just get some RTV silicone and run a very thin bead on that area around the leak and be done with it.
The silicon is not a bad idea, maybe try a thin strip on the gasket and let it dry throughly before reinstalling, you need to access those valves regularly … don’t use so much that it seals like glue. ……….Blitz