800GS - Look at My Cam and Oil Leak

Discussion in 'Parallel Universe' started by Lost Roadie, Mar 21, 2009.

  1. k woo

    k woo 308Master

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    I worked 4 years operating CNC machining centers making engine components for Cummins Diesel. From your photo the casting that the cam was machined from had a severe case of what is called "porosity", a void of material. This happens during the casting process prior to machining and is why you found no chunks of the cam during oil and filter changes.

    Google "casting porosity" for more info and print out what you find. Take this information with you to the dealer.

    The production personnel and QA should have NEVER allowed that to slip through the assembly process. BMW owes you an overhaul.

    Good luck, keep us posted.
    k woo
  2. a1fa

    a1fa Throttle Jockey™

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    I have a theory.. it's because the bike leans so far to the left, the oil leaks through the rings and then gets burned up :huh
  3. SCVGS

    SCVGS Adventurer

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  4. Emmbeedee

    Emmbeedee Procrastinators

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    It's a design feature to lube the cams...
  5. k woo

    k woo 308Master

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    I stand humbly corrected after seeing the pictures from SCGVS.
  6. JoelWisman

    JoelWisman Long timer

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    Lol. If it makes you feel any better, the first time we saw that in the shop we assumed horrible QC, as well. Fired off an email to our FSE (district service rep) and were told it's by design for lubrication, but still might not have believed him had we not since seen many many and all F twins have that void.
  7. JRWooden

    JRWooden Long timer

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    I'll fess up too ... add me to the list ... the first time I saw a picture of the cam I said the same thing... "What crappy QA ... I hope there's not a load of debris in the bottom of the crankcase..." :confused

    it was a few days later that I learned it was a rather elegant way to get better lubrication in the cam lobes ... :lol3
  8. Catskill

    Catskill tree hugger

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    Sorry to dig this thread up but I just noticed an oil leak similar to this one.

    Was there EVER an explanation given?

    I cleaned the leak and it hasn't returned but now I'm afraid to take my bike back out. I checked my oil level and everything is fine. I don't know how long the oil was there could have been a week or a day since I never clean my bike and only inspect the chain and tires before I leave....
    [​IMG]

    [​IMG]
  9. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    I wouldn't worry. A seep like that will take forever to add up to any noticable oil loss. Just keep an eye on the level and get it fixed when you can. I think the culprit was a warped valve cover.
  10. Lost Roadie

    Lost Roadie Rider

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    There's a more extensive thread around here about these leaks, mine was just the first.
    Some people use gasket seal to "stop" the leak...

    The reason I was given by Gina's BMW was the valve cover itself was not square, therefore causing the leak.

    I gave up.

    I wouldn't worry about riding your bike, I just put on another 13,000 miles with a leak like this, though not quite as bad.
    3rd time it's leaked after being "fixed"

    I'm far out of warranty and since I stopped stressing about this leak the more I have enjoyed the GS.

    It's just part of the personality.... and embarrassment for BMW engineers. :deal
  11. Singletrack_mind

    Singletrack_mind Cave Man

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    I've actually been surprised how much oil this engine weeps from seals here & there. No way no how does it "leak oil" in any noticeable quantity, but on my bike the water pump, cam cover and clutch cover all weep oil so the engine is a filthy mess pretty much all the time. I'm not worried about it, but as I say, surprised.
  12. soph9

    soph9 Would Love to ride ALL the TIME

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    we just had our valve seals replaced for the second time and we both have new bikes although over 28000 KM on them...faulty seal gasket is what my service guys are calling it and apparently BMW has issued new seal kits for both our bikes and were replaced this past Saturday. We shall see if this works. The leak was first noticed at 25000 KM for me.
  13. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    Do you mean valve cover seal?

    Valve seal replacement is no simple matter, and it is very different from replacing the valve cover seal.
  14. Catskill

    Catskill tree hugger

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    Thanks guys.

    I feel better now.

    I don't normally 'FREAK OUT' but the thought of my bike being broken got me really depressed when I saw that oil.

    I put 12K happy miles on since April when I got her. I'm trying to hold out 'till it snows before I bring her in to the shop for (I guess) the electronic update.

    I've changed the oil 3 times so far and the air filter once and I check the chain regularly and clean it with my fancy schmancy chain brush....just got a damn chain recall in the mail but...that will have to wait-I've got some more riding to do. I've gone 12k on the current chain with no issues so I'm not going to flip over that now.
  15. soph9

    soph9 Would Love to ride ALL the TIME

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    Cover seal
  16. jscottyk

    jscottyk Been here awhile

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    Keepin' this one alive :D I have follow up question for all you motor guru types...

    Could these leaks be caused by excessive internal crankcase pressure? This is always an issue on constant-high-RPM road race singles. Supermono types. Also rears it's ugly head in singles in flattrack racing. There are a number of way people try and deal with it but the most effective seems to be some sort of one-way crank vent.

    My thinking here is since the F800 is a 360* twin, it's effectively a big single with regards to this topic. The semi-dry sump seems to take care of the motor pumping all of it's oil out (trust me, I've seen that happen on a hod-rod single and it aint pretty) but the crankcase venting seems to be overwhelmed thereby leading to excessive internal crankcase pressure. Here's a link to some info on the concept from Michael Moore of eurospare fame. Also, here's a recent conversation in the tuners section at flattrack.com that discusses the topic.

    Any thoughts?