Engine: Oil leak

[Michael J Hawk]

Been awhile since I've posted and I've inquired about this before. I have a '61 Hawk with a 289. My problem is with a persistent oil leak from the rear of the oil pan. I have removed it a installed a new gasket being careful in the area of that stubborn rear seal around the rear cap. I recently removed the transmission for a rebuild and because the inside of the torque converter housing and converted itself were bone dry I felt satisfied the rear main seal wasn't leaking. What confuses me is it will leak when the car is just sitting sometimes. I would expect it to drip after being driven but days after the puddle has been removed I will find another one. Any suggestion. Makes no sense to me.
I hate leaks.

[JoeHall]

I just went through that with the 62GT. There's no way I'd remove the oil pan and not replace the rear main seal while in there, just for insurance. The rear main seal will also continue to drip overnight, and leave a puddle next day. While at it, I'd clean and scuff (with 320 grit) the seal journal on the crank, where the seal lip rides. I also had a head gasket leaking at the same time, but it was coolant. I could not discern the coolant leak till the oil mess was cleaned up. You might wanna buy a dentist mirror, to look carefully around the rear of the block, because there's half dozen places it could also be leaking: pipe plug fittings; oil pressure line and/or fittings; rear cam plug; oil filter and/or its mount, head gasket(s); rocker cover(s), etc..

I found a perfect dentist mirror at Sears, with an LED light built into it.

[Studebakercenteroforegon]

I just went through that with the 62GT. There's no way I'd remove the oil pan and not replace the rear main seal while in there, just for insurance. The rear main seal will also continue to drip overnight, and leave a puddle next day. While at it, I'd clean and scuff (with 320 grit) the seal journal on the crank, where the seal lip rides. I also had a head gasket leaking at the same time, but it was coolant. I could not discern the coolant leak till the oil mess was cleaned up. You might wanna buy a dentist mirror, to look carefully around the rear of the block, because there's half dozen places it could also be leaking: pipe plug fittings; oil pressure line and/or fittings; rear cam plug; oil filter and/or its mount, head gasket(s); rocker cover(s), etc..

I found a perfect dentist mirror at Sears, with an LED light built into it.

And you could add the distributor gasket to your list. Not because they are known to leak, but sometimes when the distributor get pulled it gets re-installed with a missing or damaged gasket.

[BRUCESTUDE]

I hate those leaks too! The Stude V8s I've rebuilt or resealed have usually developed a small drip after a few hundred miles, and after checking and tightening to no avail I just began wadding up a couple blue shop paper towels, then jam them between the oil pan and bell housing cover. It doesn't stop the drips, but keeps the floor clean!

[JoeHall]

To the OP again: The rear seal is not likely to sling outward, nor result in wetness inside the bell housing, nor get on the face of the TC. It usually just runs downward, between 4 and 8 o'clock. If you put the car on a lift its easier to check the seal: remove the shroud plate that bolts to the lower half of the bell housing face (must remove starter first), then wipe the area dry. Reinstall the starter, but leave the shroud plate off, then lock the accelerator linkage to run the motor at 2000-2200 RPM for about 45 minutes. Drop the motor back to idle, then crawl under the car with a strong light. At that time, if the rear seal is leaking, you will see it. If no leak, then is a good time to check all the other suspected areas while the motor is hot and still running.

[(S)]

Dist gasket is probably number 1, and the oil pressure gauge line is a close number 2........ I agree, run the car and see what happens. I would also say. overfill it by one quart, and your result happens sooner........

[Mrs K Corbin]

Aw c'mon it's a Studebaker marking it's territory....

[altair]

Make sure your breather is clear and not creating excessive crankcase pressure.

[Michael J Hawk]

I never considered the distributor gasket. I will also try the JoeHall suggestion. I want to drive it to South Bend in May and am trying to get all these squirrely things fixed.

[jclary]

I never considered the distributor gasket. I will also try the JoeHall suggestion. I want to drive it to South Bend in May and am trying to get all these squirrely things fixed.

Me too neither...for all the years I've been tinkering with these contraptions, I don't know (or forgot) if I've ever noticed or paid attention to a distributor gasket. Shucks, there are so many opportunities for oil leaks on these old engines, I've stopped being too worried if they mark their territory a little. It is when they leave "puddles," or enough to get on the exhaust and leave an embarrassing smoke trail that gets me motivated to tighten things up.

So now, I will get my mechanics mirror & check for any sign of a distributor gasket next time I'm raising hoods. Just think of all the places on the engines (six or 8) for oil leaks. Front timing cover, front oil pan, fuel pump pivot pin, valve covers, draft tube, filler cap blow by, valley cover, rear main seal/pan gasket...I'm sure I've overlooked something.

[JoeHall]

Looking for puddles helps: a distributor gasket leak will usually puddle along the casting ribs just behind it; a front felt seal will usually puddle in the rear lip trough of the front cross member on the frame. Its also easy to get an eyeball on, from below the car. Ditto for leaks around the fuel pump mount.

Looking for smoke sources also sometimes helps trace down an oil leak: the rocker covers usually leak on the low side, and/or at the rubber grommet; either will run down onto the exhaust manifold and smoke. One thing for sure, its a relief to finally be able to put an eyeball on the leak, but that's not always possible.

[TWChamp]

My 1950 Champion uses some oil, and I wasn't sure how much was due to leaks.
I took this picture last fall, and need to clean this off to see if it's from leaks, or from blowby out the breather.

[StudeRich]

That is looking a Lot like a cracked, worn or loose brass Oil Filter fitting or Hose!

If it were Blow-by Oil from the Filler Cap I would think it would go higher from the fan air flow.

[Michael J Hawk]

I'll just pass this on in case it helps anybody. It's not always practical but sometimes you clean a suspected area with brake cleaner and then poof some baby powder on it then start the engine and let it run. Good contrast between the oil and powder. Difficult if you're working from underneath though.