[gtorich]

Then I used my shop vac to push air into the oil fill hole on the rocker cover for 30 seconds. This slightly pressurized the crankcase.
When I removed the paper towel strips, they had oil on them, confirming it was the rear main seal leaking.

Thought i would keep you guys entertained for a saturday...........did this today with less than desirable results.

Just wondering, could a shop vac push this much oil on the floor, i had it on for about 20 seconds..........dont know my wife was screaming under the car, had to put my beer down to see what the issue was...........lol

Pic 1 was after the test, oil all over the flywheel

#2 before test flywheel seems ok, maybe a stain or two, but cant feel any oil, but there was a drip by the u channel.

Oil on starter bolts, this was before the test was taken............i cleaned everything up before test.

Oil on floor after 20 or so seconds..........wife wasnt happy.

other pics after test.

Next step is getting a smoke tester............hopefully this show me whats up with the leak.

Guess no matter what the motor has to come out again..............this will be he 4th time for this, ...............guess im at a crossroads for this ..............dont want to do it again...............or sell the car for a loss.

Just wondering if pushing with the shop vac, could that lift the oil up to flow out either the rms or the oil pan...........seems weird to me.

Rich

[67drake]

I think you owe your wife dinner!

[steve25]

Depending on the elevation you live at the crank case is already statically pressurized at near 14.7 psi and then you boosted that by near that same amount again.

No wonder it found the source of the leak for you! :-)

[gtorich]

Originally Posted by steve25

Depending on the elevation you live at the crank case is already statically pressurized at near 14.7 psi and then you boosted that by near that same amount again.

No wonder it found the source of the leak for you! :-)

Thanks Steve, never thought about that............dont know if i wrecked anything, it was leaking anyways...............with all that oil mess, i still dont know if it came out the rms or the bottom of the oil pan..

Im thinking with the oil in the pan lower than the pan seal, could the shop vac air lift the oil that high.........

Guess bottom line this motor has to come out again, not sure i want to put the same motor back in, this has been fixed 3 times and always the same result.

Thanks for hanging in there with me guys

Rich

[Half-Inch Stud]

Only if overfilled by 2 quarts or more. Should come out the dipstick tube before puoring out elsewhere.

[mgarblik]

OK, you have verified oil is leaking out the back of the engine in 1 of 6 possible places for sure. No way I would remove the engine with all the issues you have had without a smoke machine, the transmission removed, and the flywheel removed first. 6 possible leaks: 1. left oil gallery screw in plug. 2. right oil gallery cup plug 3. Camshaft rear plug 4. rear main cap to block mating surface 5. Rear main seal 6. Oil pan gasket over the cap or in the corners. You MUST find the exact leak path to effect a proper repair. It is also a very rare possibility the block is cracked somewhere in the rear which can be corrected as well. I have had a few Pontiac blocks crack where a plug was driven in at such an angle they cracked the block and also where the tapered plug was screwed in so deep the pressure cracked the block in the threads. I was able to repair the cracked blocks with the engine installed using a silicon bronze rod and a tig welder. 20 minute repair. But you have to find the leak for sure.

[gtorich]

Thanks for that info Half-Inch..............i think with the previous leaks, i maybe had 5 1/2 qts in pan............so i guess where talking rms leak, of course the one with the most work involved would be the one.

Not sure i want to try the bop one piece again, the guy who installed it said he was quite familiar with these...............idk, got to come up with a new game plan.

Rich

[geeteeohguy]

This reminds me of the time I used shop air to clean out the carbs on my '68 Honda 350. The pressure totally destroyed the brass floats. Never did that again. Then there's the guy on the Corvette forum who removed his intake manifold, drilled 1 inch holes into the runners, and installed pipe plugs into them so he could remove them periodically to check the camshaft for wear. And a member here from OZ who drilled the rear axle and axle bearing races on his '67 GTO to install zerk fittings so he could lube the bearings. All sorts of ways to stay busy in this hobby.

[gtorich]

Originally Posted by mgarblik

OK, you have verified oil is leaking out the back of the engine in 1 of 6 possible places for sure. No way I would remove the engine with all the issues you have had without a smoke machine, the transmission removed, and the flywheel removed first. 6 possible leaks: 1. left oil gallery screw in plug. 2. right oil gallery cup plug 3. Camshaft rear plug 4. rear main cap to block mating surface 5. Rear main seal 6. Oil pan gasket over the cap or in the corners. You MUST find the exact leak path to effect a proper repair. It is also a very rare possibility the block is cracked somewhere in the rear which can be corrected as well. I have had a few Pontiac blocks crack where a plug was driven in at such an angle they cracked the block and also where the tapered plug was screwed in so deep the pressure cracked the block in the threads. I was able to repair the cracked blocks with the engine installed using a silicon bronze rod and a tig welder. 20 minute repair. But you have to find the leak for sure.

I hear ya on that Mike, im thinking if i have to yank the transmission out, then the flywheel to boot..........wouldnt it make more sense to just pull the motor out and do the smoke test to make sure...............dont know if some of those things you pointed out can be fixed while motor is in car.........ifs its the rms , that has to come out one way or the other................i sometimes just wonder why does everything have to be the hard way with me............but thats the way i roll.

Gonna see if i can rent a smoker, idk if they are for rent anywhere by me, otherwise im gonna buy a somewhat cheapy.

Rich

[mgarblik]

Personally, I would smoke test it while the engine is in the car. Here's why. You are due for some good luck and it's possible the problem can be fixed with the engine in the chassis. Leaking at rear of valley cover, in car. Leaking at distributor, in car, oil gallery plugs, in car. Corner of oil pan or rear cap to block, possibly in car. If the pan has to come off or rear main seal is leaking for sure, then engine needs to come out again unfortunately. I would want to know for sure before pulling it. I really hope you get lucky.