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Thread: Leaking Head Gasket

  1. #1
    Senior Member
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    Arrow Leaking Valve Cover Gasket

    Hello everyone,

    I just came back from a 1000 mile trip to find that around mile 800 the seal where I remove the valve cover was weeping oil. Enough to spray some droplets over the engine case on the brake side. I did my own valve checks at 8000 miles each and the bike has 20000 miles at the moment. I did take the bike in to 95 degree weather for a day but the rest of the weather was moderate. I checked the oil level and it was filled to the top and I checked the torque of the valve cover bolts and they were fine as well. Could I wait until the next valve clearance check to replace the gasket? What else could have caused the weeping? Too much oil? Bad seal 4000 miles ago? I'll post some pictures when I get some day light. Thank you for reading and your input.
    Last edited by MiG Angel; 26th July 2015 at 08:03.

  2. #2
    Senior Member Leaking Head Gasket Lou Wambsganss's Avatar
    Bike: 2012 NC700X, 1979 GL1000
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    The head gasket and the valve cover gasket are two different things. The head gasket is a much larger problem. From what you describe, it sounds like it's just the valve cover gasket. It's not a big problem. It can leak from being pinched or cut during reinstallation, from hardening over time, etc. If it's just a slow weep of oil, I'd say just let it be for now and replace it the next time you have the cover off. I think Honda probably recommends replacing it whenever the cover is open anyway (although I've never changed mine and have no leaks yet...)

  3. #3
    Senior Member Leaking Head Gasket Lou Wambsganss's Avatar
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    Also, it might be the vent line on the upper RH side of the valve cover. There is a maybe 1/2" dia black rubber line that vents the crankcase. If that line is not tight, it could also leak engine oil down the RH side of the engine.
    (All RH/LH sides as sitting on the bike)

  4. #4
    Senior Member Leaking Head Gasket
    Bike: 2012 NC700x
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    Quote Originally Posted by MiG Angel View Post
    Hello everyone,

    I just came back from a 1000 mile trip to find that around mile 800 the seal where I remove the valve cover was weeping oil. Enough to spray some droplets over the engine case on the brake side. I did my own valve checks at 8000 miles each and the bike has 20000 miles at the moment. I did take the bike in to 95 degree weather for a day but the rest of the weather was moderate. I checked the oil level and it was filled to the top and I checked the torque of the valve cover bolts and they were fine as well. Could I wait until the next valve clearance check to replace the gasket? What else could have caused the weeping? Too much oil? Bad seal 4000 miles ago? I'll post some pictures when I get some day light. Thank you for reading and your input.
    As stated above, you are describing a valve cover gasket - not a head gasket. That is a very good thing.

    When you adjust your valves, sometimes you can seat the valve cover gasket improperly and cause it to leak when you put everything back together. Other times the gasket itself just goes bad when you remove it from the cover. But thirdly, and often overlooked, the rubber washers that the valve cover bolts seat into can wear (or rather, compress) overtime, and that will prevent the valve cover bolts from applying the proper amount of pressure on the valve cover itself, thus, causing the valve cover gasket to weep a little bit.

    I would recommend you replace the rubber washer seats that the valve cover bolts sit on, and while you're there, replace the valve cover gasket.

    I would not wait until the next valve adjustment, as that's another 8000 miles, but you don't need to do it this instant either.

  5. #5
    Senior Member treybrad's Avatar
    Bike: 2012 NC700X
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    I'd start easy (and free). Loosen all the fasteners and pull the valve cover up a bit to see if there's any obvious deformity in the gasket. Should be able to do that without messing with the radiator. If it looks good, re-torque the bolts and see if it still leaks. As Antarius mentioned, pay close attention to the rubber bits on the bolts and see what they look like. Shouldn't take more than 20 minutes to inspect things like that.

    I wouldn't worry about the weather, I commute on mine in 100F+ all summer, the rider is the weakest link when it comes to that

    trey

  6. #6
    Senior Member
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    You've got great suggestions here. I can only second them. I'm just replying to underscore what trey said: the warm weather didn't do it. I don't recall whether I've ridden this particular bike at 120F, but I've ridden it many miles at 115F and above. It doesn't mind in the least.

  7. #7
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    [QUOTE=Antarius;138703]"But thirdly, and often overlooked, [b]the rubber washers that the valve cover bolts seat"

    It's been a long time since you posted this, but it was really helpful today. I adjusted my valves today, and afterward oil was spewing out from the lower throttle side valve cover bolt. I came across your post after a quick search. I left off one of those little rubber washer's during reassembly. Thank you for your contributions to the forum Antarius! You saved me a lot of stress and time today.

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