Mystery Leak

[leadrsa729]

Hi All -

I rebuilt my 72 2.4L engine and have begun the breakin process. I took it out for the first drive and brought it home to inspect. I'm seeing a rather heavy leak that is collecting at the bottom of the case, but seems to be coming from in between the block and the chain housing as far as I can tell. It's hard to tell for sure, but when I look from the top of the engine in that are I can't see anything. Any ideas on where this leak might be coming from?

Thanks in advance for all your help!

[deftom]

Hello,

I think a picture of what yoûre seeing my help.

good luck

[lvporschepilot]

Make sure those old hoses to the cam housings and the seals from the cam seals to the chain housings are not leaking.

[Flat6pac]

Did you crimp the rubber O ring? That becomes a leak
Or did the paper 3 hole gasket get off location, another possible leak
Either of those are a considerable amount of oil.
Lesser oil is on the back of the chain box where it’s important to look at the factory seal with JBWeld.
Run it and watch
Bruce

[leadrsa729]

Thanks guys, to get to these seals I have to pull it all aprat and rest the timing correct? Is it possible to set the cam timing with the engine still in the car?

Here is a link to a video I took where it ends zooming into the space between the heat exchanger and the chain box. You can kind of see the oil trail.

https://photos.app.goo.gl/orkCHFjRSfnUDNep6

[deftom]

For what I saw it could be the o-ring from the chain tensionner if you have the hydrolic one???

[mikedsilva]

Originally Posted by leadrsa729

Thanks guys, to get to these seals I have to pull it all aprat and rest the timing correct? Is it possible to set the cam timing with the engine still in the car?

Here is a link to a video I took where it ends zooming into the space between the heat exchanger and the chain box. You can kind of see the oil trail.

https://photos.app.goo.gl/orkCHFjRSfnUDNep6

I had a similar leak a while ago and turned out to be the banjo bolts that connect the rubber oil hoses between the cam tower and the case. Have a good look at those connections to see if there is any oil. With fresh clean oil, it is sometimes harder to spot the leak (not as obvious as dirty brown oil).

[leadrsa729]

*Update*

I pulled the engine tin off and started it up. Had a look around while it was running and yes it seems the leak is coming from where the chain box touches the camshaft tower. You can see the wetness in the pic in the link below. Its right where I have the light focused.

https://photos.app.goo.gl/Q6LQM66yy8azfTA77

So what are my options here? Do I have to drop the motor again, open the chain housing, pull the camshaft and reseal everything here? This is a ton of work for me and means I won't be driving this year if so. Thanks in advance for your help!

[Eagledriver]

I think you can fix it without pulling the engine. Pull everything thats in the way (muffler, rear valance, engine tin, etc). Might have to remove the engine mount. You only need to remove the chain sprocket, I don’t think you have to remove the cam. You need to remove the aluminum piece that the o-ring goes on and reseal it. Most likely the aluminum piece is warped due to over tightening. It needs to be flattened so it fits tight against its gasket. I would use fine sand paper on a flat surface to take down the high points.

-Andy

[deftom]

You can dot it with the engine in the car,

I did this operation in the past. It took me something like 10 hours.

You have to remove the engine mount to have some space.

Also remove the skirt (correct word??).

Don't forget to jack up a little bit the car when you remove the rear engine mount and put some wood under the exhaust.

Good luck

[leadrsa729]

Thank you guys! Big question on my mind is will I have to reset the cam timing? I’m assuming so if removing the cam sprocket and chain. If so I would probably need to remove the deck lid so I can maneuver the torque wrench on that but.

[deftom]

Yes you have, I can loose all the rockers arms (except the number one ignition of course) in order to performe easily the timing

[Walt Fricke]

I did this once. It was a race motor with modified tin and no muffler, and the deck lid just lifted off, so I had a much easier time with that. I did it in the trailer in a Walmart parking lot in Las Vegas heading to a race. Wife helped me. Removing the deck lid on a street car isn't all that complicated if you just keep track of the shims/washers used in the four Allen bolt locations. Don't recall about the two parts of the rear motor mount, but not tricky - just put something under the engine, like a jack so you can take off the cross bar part.

I had forgotten to tighten the three 10mm head bolts on the right cam side! So I didn't have to pull the inner "sprocket" - the thing the pin goes into from the toothed gear and is held on with the Woodruf key. A gasket or O ring would require a bit more removal. I forget how I handled the tensioner. I didn't have a vice, which is how I usually squeeze it back so I can pin it for the install.

When I put the gear and chain back on and did a preliminary semi-tighten of the cam nut and checked the timing, it was spot on. The pressure and counter pressure from all those springs kept the cam from moving at all.

So leave the rockers alone. And do your best, once you are in there, not to move the cam once you have broken the torque on the big nut. And don't move the crank.

However, if you find the cam timing is off a bit on reassembly, not a big deal. Just retime in the normal way. Don't have to reset the lash if you checked the timing for that cam before disassembly.

[OSC911]

Originally Posted by afterburn 549

baby powder is your friend-
Throw it on and the oil leak will leave a trail.

When I am chasing a leak that is hard to find the source I also use baby powder. I degrease the engine or area that I think the leak is coming from. Let it dry and use the baby powder in a degreaser gun. Shows any weep or leak perfectly.