Engine: Oil Leaks

[Kato]

I know they say if a Stude isn't leaking some oil it means it's out of oil but I'm trying to at least slow the flow, as it were!

I've changed the rocker cover gaskets and that has helped but it still leaks oil while from the rear of the engine. It continues to leak while not running pretty much continuously. It's not a terrible amount but a little oil looks like a lot of oil!

My question, if a rear main seal is the culprit would it continue to leak for many days and weeks after the car has been running or would this indicate the pan gasket is the culprit? Of course I am hoping for the latter!

Thanks!

[bensherb]

In my case it was the pan gasket, which in my opinion would be surprising if it didn't leak. There is a massive cork "bar" that seals a massive gap at both ends of the pan. The cork shrinks over time and leaks. Replacing the pan gasket is a bit*#! After reading about it on this forum here, the consensus was it's easier and faster to pull the engine and do it out of the car. I decieded to do it the easy way and remove the engine. It took an hour to remove the engine, a couple days to replace the gasket and an hour to put the engine back in (it would have taken much longer if I had help). I can't even imagine trying to replace that gasket in the car. I also straightened and reinforced the pan flange with 1/8" flat bar so bolt tension is better distributed, and used a sealer called "The Right Stuff". It seems to have done the job. Now there's a tiny leak coming from the timing cover that wasn't there before.

[Kato]

In my case it was the pan gasket, which in my opinion would be surprising if it didn't leak. There is a massive cork "bar" that seals a massive gap at both ends of the pan. The cork shrinks over time and leaks. Replacing the pan gasket is a bit*#! After reading about it on this forum here, the consensus was it's easier and faster to pull the engine and do it out of the car. I decieded to do it the easy way and remove the engine. It took an hour to remove the engine, a couple days to replace the gasket and an hour to put the engine back in (it would have taken much longer if I had help). I can't even imagine trying to replace that gasket in the car. I also straightened and reinforced the pan flange with 1/8" flat bar so bolt tension is better distributed, and used a sealer called "The Right Stuff". It seems to have done the job. Now there's a tiny leak coming from the timing cover that wasn't there before.

Yes I've heard it is a *# of a job. Did you split the eng from the tranny or remove them together?

[JoeHall]

I have replaced probably a dozen oil pan gaskets and rear main seals with motor in the car, and cannot imagine pulling the motor for that job. (If in doubt, always replace the rear main seal anytime the pan is off.) Just get the car up good and high, and level. I use ramp stands, front and rear, and then add a 2"x6" piece of board for even more elevation. Cock the wheels all the way, right or left, to swing the tie rods out our the way. Insure you have a clean working area, strong light, and good, comfortable creeper (a quality creeper is your friend). Then just get used to working while laying on your back. It is not an overhead job, it's a laying on your back job, and there's a difference.

For the job, with motor out or in, take your time and don't overcomplicate it. It's just gaskets and, "bubblegum" sealer. It is helpful to use 1.5", pointed studs on each corner, to help initially align the pan If the motor is in the car, no need to remove much other than the starter. Maybe one or both exhausts, must be disconnected at the manifold and dropped down, depending on the exhaust design. All together, it will take about 4 hours the second time, but maybe eight hours the first time. For me, pulling the motor takes four to six hours, and about eight-ten to reinstall it. I once had to remove & replace the pan on a 56J about four times in a week, when trying to get an Oldsmobile pump to work properly and not blow the rear main seal. The 56J is more difficult because the tie rods and octopus must be removed. The 289/259 is a piece of cake. LOL

[altair]

Before you start chasing oil leaks make sure your breather cap is clear, excess crankcase pressure will force oil out every where and all the gasket changing will not fix it.

[jackb]

engine vs. motor......no biggie......I did a few under the car in my 20's.......not now......with the engine on the stand, you can then take care of the expansion plugs and the block crud.... that way you don't have to chase water wetter, fan pulleys, radiators, etc....

[Kato]

I have replaced probably a dozen oil pan gaskets and rear main seals with motor in the car, and cannot imagine pulling the motor for that job. (If in doubt, always replace the rear main seal anytime the pan is off.) Just get the car up good and high, and level. I use ramp stands, front and rear, and then add a 2"x6" piece of board for even more elevation. Cock the wheels all the way, right or left, to swing the tie rods out our the way. Insure you have a clean working area, strong light, and good, comfortable creeper (a quality creeper is your friend). Then just get used to working while laying on your back. It is not an overhead job, it's a laying on your back job, and there's a difference.

For the job, with motor out or in, take your time and don't overcomplicate it. It's just gaskets and, "bubblegum" sealer. It is helpful to use 1.5", pointed studs on each corner, to help initially align the pan If the motor is in the car, no need to remove much other than the starter. Maybe one or both exhausts, must be disconnected at the manifold and dropped down, depending on the exhaust design. All together, it will take about 4 hours the second time, but maybe eight hours the first time. For me, pulling the motor takes four to six hours, and about eight-ten to reinstall it. I once had to remove & replace the pan on a 56J about four times in a week, when trying to get an Oldsmobile pump to work properly and not blow the rear main seal. The 56J is more difficult because the tie rods and octopus must be removed. The 289/259 is a piece of cake. LOL

Thanks Joe, great advice.

[bensherb]

Yes I've heard it is a *# of a job. Did you split the eng from the tranny or remove them together?

I took them out seperately. I had a 3pd OD, it's just 4 bolts to remove plus the shifter links, and very easy; once the driveshaft is out. I replaced the engine without the belhousing, clutch and flywheel. I replaced them with a GM 4L60 AOD trans.

The biggest problem I had with the pan gasket was getting those cork bars to bend around the front and rear, and stay there long enough to get the pan in place. Gravity works. One tip I heard after I did it, is to curve those end cork bars inside a 3lb coffee can for a few days to get them to take a curved set before attempting to install them. If they do that would help a lot.

[RadioRoy]

Has anyone tried replacing the cork bits with the kind of rubber they make O rings out of? It seems to me that as much trouble we have with oil pan leaks, some more modern parts would help.

[JoeHall]

I took them out seperately. I had a 3pd OD, it's just 4 bolts to remove plus the shifter links, and very easy; once the driveshaft is out. I replaced the engine without the belhousing, clutch and flywheel. I replaced them with a GM 4L60 AOD trans.

The biggest problem I had with the pan gasket was getting those cork bars to bend around the front and rear, and stay there long enough to get the pan in place. Gravity works. One tip I heard after I did it, is to curve those end cork bars inside a 3lb coffee can for a few days to get them to take a curved set before attempting to install them. If they do that would help a lot.

For the cork bars, instead of a coffee can, I use two tie-ties to form them into a tight 'D' shape, and leave them in place for a couple of weeks before beginning the job. That way, they just lay right into place and you don't have to struggle with them. For the little rectangular cork pieces on each side of the rear main cap, use a pen knife to cut them so they are just slightly oversized, then slather them with sealant and use a blunt screwdriver to push them into the recesses; this provides a flat surface for the pan gasket in those corners. Similar for the front end of the pan. Nothing to it, do it on your back, standing up, or standing on your head. LOL