Oil leak - fixed everything I know of with no success

The bike is an 82 XJ750J, and it's leaking oil from the valve cover gasket on both of the camshaft plugs (integral to the gasket on this bike, not separate pieces).

I first replaced the gasket, and noticed that a few of the cover bolt holes were stripped, so I drilled them and did HeliCoil inserts on three of the four holes on that side. The bolts are threading well and holding tight, so I don't think I botched anything there. After putting it all back together, it was still leaking, so I ordered the full set of a dozen mounting rubbers (donuts) from chacal and just finished installing them.

It's still fricking leaking!

I'm kind of at the end of my rope. I'm really tired of having the engine smoking at stoplights, having to add oil, and only being able to wear black pants when riding. Any thoughts or suggestions welcome.

 

I can't imagine if it was all clean and you used some gasket sealer around those 1/2 moon plugs it would leak. I use Permitex Ulrta Black sealer , works great for that job.

MN

 

I was planning on giving RTV a shot as a last resort. Still baffled though; it *should* seal without any additional sealant, shouldn't it? I'll let you know how the RTV solution works out.

Thanks.

 

Is your cover warped? I haven't heard of this happening but anything is possible. You could get a piece of nice flat glass and lay it down and use a light to see if it's actually flat or not. Where does it appear to leak from?

 

http://www.xjbikes.com/Forums/viewtopic ... cover.html

 

Guess I hadn't thought of checking the cover. I'll verify that it's not warped next time I have it apart, but it's leaking from two spots in a way that makes warping seem to be an unlikely culprit.

I guess I'm not positive on the spot from which it's leaking because I can't see it pulsing out or anything. However, I'm pretty sure that it's from the bottom of the camshaft (half-moon) plugs on the right side of the engine. The reason I'm pretty sure about that location is that oil pools on the cooling fin right below the bottom of those plugs, and it's done so when I've been test riding it or had it on the center stand. If oil was just running down to there from somewhere else, I'd expect it to pool different places based on the bike's angle.

 

You did read the linked post that adrian1 posted immediately above your last post, right? If the cam cover gasket is what's leaking, you need to read that post.

 

You did read the linked post that adrian1 posted immediately above your last post, right? If the cam cover gasket is what's leaking, you need to read that post.

 

Yup, I read it. I'm not sure it told me anything that I hadn't already been doing though. That's what has me so frustrated.

One thing I'm wondering about is whether the torque spec is still valid with a steel insert, but I'm concerned about over-torquing those bolts.

 

The valve cover bolts have stop collars on them. The torque spec of 7.2 ft/lb is not very tight; just "functionally" tight. You basically tighten them until they STOP and that's it.

A couple of 'spots' of RTV on the gasket, right where the "half moons" join the rest of the gasket, may solve your leak.

 

Post some pictures of this oil leak.

 

I'll have some pics up in the morning if it's still leaking. Working on it right now.

 

Just out of curiosity, when you did the Heli-coils did you make them so that they are flush like the originals? I would think that maybe a couple of thou higher may prevent the shoulders from going down all the way and even at the correct torque settins, may be enough of a gap to let oil seep out.
Just my two cents.
Good luck and keep us informed.

 

It looks like the dabs of RTV finally did the trick. I'm still a little mystified as to why it was necessary, but at least the leak is cured.

Thanks for all the advice!

Now, off to degrease the engine!

 

Yup, I have them all at least a quarter turn below the surface.

 

A long-term follow-up . . .

This spring I was doing some more major maintenance, including valve shims. While I was ordering a couple hundred dollar's worth of parts from Chacal, I decided to go ahead and try out another valve cover gasket, even though the one I installed last year was brand-new (purchased from my LBS). The new gasket I received from Chacal had somewhat different (and robust) construction in the camshaft plug area. When I put everything back together, I scraped off all the RTV from last year's attempt, and used the new gasket. Whatdaya know. No leak.

Ultimately, it looks like the part I got from my local shop was defective or just low quality.