Head Gasket seapage

[captjerry]

Have a slight oil seapage which appears to be from the head gasket, the far right hand (#4 cylinder) rear nut. In a 200 mile ride maybe 2 drops (but you know how that looks on hot fins seaped out.)
1.Should I change it out?
2.Expect it to get worse?
3.Will it possibly stop in warmer weather?
4. Wait for it to get worse?
What can I expect???????

Need some advice.
J

[TopCatGr58]

Hey there Capt. Jerry,

I've got the same year-model. No offense intended or implied, but are you sure it's actually from around the head nut, or just trickled there from the Valve cover gasket?? Those half circle rubber cam opening plugs tend to shrink and can leak, not to mention all of those pressure points of the valve cover. With the engine naturally tilted forward, it's easy for the oil to get to that fin from behind or the back side of the engine as well.

SO, aside from cleaning around and above that spot and then reinspecting after another ride to rule out a leak from above, you could simply try retorqueing the nut, however after it has sat essentially untouched for who knows how many years, you might not be able to get an accurate torque on it. During my rebuild, the manual recommended a slight amount of oil to be placed on the threads and contact surfaces of the head nut to allow it to turn more easily so that you might get a more accurate measure of true torque, and not just friction resistance. They only torque to 25 ft.lbs.

I did a topend job, torqued them, then fired the engine up to operating temps, then let it cool, and then retorqued, and haven't touched them since.

I can't say that I've actually seen or heard of any oil leaks from these nuts, but anything's possible, but I would more likely suspect another site flowing to/around the nut from above, behind!?!? HTH?!

[captjerry]

Thats the first thing I thought was valve cover, however with checking all around with a flashlight even, everything is bone dry above the area.
I have retorqued the head however, at spec I didnt budge not one of the nuts.
The bikes going to off the road for a couple weeks for painting, I figure when I fire it back up take it for another healthy ride and see what I got. Might possibly do a leak down test on it and see if that shows anything.
Thanks
J

[Ken Talbot]

Here's a note I retreived from my archives dealing with a top-end oil leak. Like TopCatGr58 says, I'd put my bet on the valve cover gasket:



Aha, now we're getting somewhere. I can just about guarantee that
the oil is leaking from the cam cover gasket, not the head gasket.
Bear with me as I try to convince you why.

This photo shows the top of the motor with the cam cover off.
[img]/forum/images/tips/20030215-dsc00301.jpg[/img]


Look at all of the distance between the bolt hole just above and left of
the red rectangle, and the bolt hole just below and to the right. This is
a weak spot as far as trying to keep oil in. The slightest seepage in
this area will run down the walls of the head and pool around the head
bolt which is just next the red rectangle. From there, it seeps through
the hole shown in the middle of the red rectangle. This hole is there to
let rain water, etc water drain off.

Now look at this picture to see where that hole comes out.
[img]/forum/images/tips/20030215-dsc00300.jpg[/img]


The warm oil will only be coming out in a very thin layer, but it will
eventually build enough to be a noticeable drop somewhere well below where
it is coming out.

To test this theory, dab a q-tip into this hole and see if it comes out
oil-free. Or , if that is not positive, stuff two q-tips side beside in
the hole, go for a bit of a spin, park for a while, then remove the q-
tips and check for oil.

If that doesn't solve the mystery, I'll buy you a beer. (Of course, you
may have to come to Revelstoke to collect it, but the offer will still
stand!!) ;-)

Let me know.........

[TopCatGr58]

Possible Leak Source

Hey there Ken and Jerry,

I went out and took another look at my engine. Those photos you provided Ken, were nice, but Jerry had mentioned that it was the outward #4 back cylinder nut, not one that is on the inside area of the head. I took a picture and noticed that there is a plug just above the head nut that looks like it's part of the machining/casting process, but think/wonder if it couldn't develop a leak and drip down to where Jerry's head nut is leaking!?!? Just a thought!!
T.C.

[captjerry]

Some great ideas here guys. In TC's picture if you directly below the left hand nut to where the head joins the jug, (paint change)
right there is where the oil seems to be coming from. I'm headed downstairs with Q-tips in hand.... good idea

[skids]

I fixed an oil leak once with RTV Ultra Black. The leak that the Cherry Bomb had was from the same bolt, but was leaking up from where the bolt passes through the bottom. The leak was just above the second cooling fin from the bottom.

[TopCatGr58]

Originally posted by captjerry
Some great ideas here guys. In TC's picture if you directly below the left hand nut to where the head joins the jug, (paint change)
right there is where the oil seems to be coming from. I'm headed downstairs with Q-tips in hand.... good idea

Hey there Jerry,

Well, after that statement, it's a bit more clearer to me where the oil leak is! I thought it was coming out around the top where the NUT actually bolted onto the head, instead of actually at the HEAD GASKET seal location between the head/jugs but PROXIMAL to the location of the outer back head nut bolt shaft!!

So...now you ARE talking about a probable true head gasket leak, and I would possibly suspect that it would worsen especially as the temps get warmer. The head is aluminum, and the stress of the heat can cause it to warp a bit more allowing for more leakage. So...right now, if your compression tests are good and even, then you might want to try to put up with a little leak, otherwise you'll need to tear down the cam chain assembly, pull the cams, to untorque ALL the nuts, pull the head, inspect it for warpage, get it surfaced if warped, and replace head gasket and reassemble. Do you really want to go thru all that until it's really necessary ie., loss in compression???

I had an engine get hydra locked and bent a piston connecting rod, but it was a water cooled engine, not sure if I've heard of getting "OIL" hydralocked with a minor head gasket leak!?
Good Luck!