Oil leak issue - moved from other forum

moparrob · 05:59 PM

moved from the tech forum in the hopes someone has some insight***

I realized this should probably be in the engine builders forum after I posted it**

I bought my used '79 3.0 from a guy who claims it had been maintained by Patrick Motorsports in Arizona - until the prior owner wrapped his car around a fence.

I'm finally getting around to servicing it by adjusting the valves, new VC gaskets, etc. The engine is mostly drained of oil but when I turn the engine on its side 90 degrees a large amount of oil (1-2 ounces) leaks out the side and onto the ground.

This is the area (in red) where the leak seem to be - or at least where I see the oil coming from when the engine is on its side.

Is this normal or should I be concerned? The valve cover gaskets are new and are properly installed. The leak seems to be near the cam chain cover but I really can't believe they are leaking such a large amount.

All input is appreciated in advance.

Thanks.

Eagledriver · 08-18-2011, 08:01 PM

You probably have a rocker shaft leaking. The oil builds up in the area near the spark plug. When you tip the motor the built up oil drains out. Pull the valve covers and look for oil in the rocker shaft bores.

-Andy

moparrob · 08:37 PM

OK, that makes some sense.

Oh yeah! There was some oil under the valve covers IIRC. I'll pull them again to double check but that may be the problem. Wouldn't oil come up from the oil return tubes anyway though? I thought the valve covers were 'sealed' with their gaskets so oil could not leak out?

So is it that simple? Do I simply re-torque the rocker shafts on that side and see if the leak goes away?

As I read Dempsey's book further on the subject it states you want to hold the nut still on the rocker shaft and torque the bolt head with an allen wrench. The torque specs are given and it says you can increase the spec to 18 ft lbs if the shaft is leaking.

Any cautions or caveats when performing this?

Thanks.

Eagledriver · 08-19-2011, 03:50 PM

The valve covers do seal the area where the rocker arms are and the oil return tubes are. They can't seal where the spark plugs are and this is where the rocker shaft bores end. You can try lots of things to get them to seal. Find the ones that are leaking and try tightening them. You hold the big end still and tighten the small end. The big end tends to not move anyway so it's usually not that hard. The next thing to try is to move the rocker arm a couple of mm to fresh bore material and see if it will seal there. If you get to where the leaks are small you may want to just call it good. The rocker bores aren't symetical (one side is wider) so make sure the shaft is centerd on the arm. It should be very close to the end of the bore on the "short" side.

-Andy

moparrob · 08-19-2011, 08:35 PM

Andy, that is an excellent explanation which I now totally understand. I'll take a look at it tomorrow and hopefully it won't be a big issue to remedy.

Thanks again for the input.

Rob

moparrob · 08-20-2011, 04:06 PM

IT DOESN'T LEAK ANYMORE!! I'm so excited. I never have this kid of luck. It seems like Murphy follows me around sometimes.

Anyhow, I tried Andy's fix - loosening the rocker shaft and moving it a few mm, then re-torque. Not a drop now. I'm so stoked.

Thanks again for all the input. Andy, if you are ever in the LA area I have a six pack of Necastle and your favorite cigar waiting for you.

Rob