Oil pan Leak
Thread Starter
Racer
Joined: Nov 2005
Posts: 409
Likes: 5
From: Orange County CA
Oil pan Leak
I just finished installing my engine and trans after removing them to detail the engine compartment and replace all of the seals and gaskets in the engine and the front an rear auto trans seal in my 71 small block coupe.
The engine rus perfect,and the only leak is at the back of the oil pan. It looks like it is coming from the rear oil pan gasket where it goes over the rear bearing cap. It drips after the car is turned off. Looking at the rubber portion of the gasket, it looks like it slipped out a little bit and this is where it appears to be dripping from. looking at the pictures, does this look like the gasket slipped out and/or crimped creating the leak?
I dont think it is the rear main seal that is leaking as the crank and flywheel appear to be bone dry.
Can I drop the pan down and reposition the gasket, or should I replace the entire gasket?
I used the 4 piece cork gasket and will plan on using the one piece Fel Pro gasket if I drop the pan.
The engine rus perfect,and the only leak is at the back of the oil pan. It looks like it is coming from the rear oil pan gasket where it goes over the rear bearing cap. It drips after the car is turned off. Looking at the rubber portion of the gasket, it looks like it slipped out a little bit and this is where it appears to be dripping from. looking at the pictures, does this look like the gasket slipped out and/or crimped creating the leak?
I dont think it is the rear main seal that is leaking as the crank and flywheel appear to be bone dry.
Can I drop the pan down and reposition the gasket, or should I replace the entire gasket?
I used the 4 piece cork gasket and will plan on using the one piece Fel Pro gasket if I drop the pan.
Drifting
Joined: Sep 2007
Posts: 1,572
Likes: 51
From: Wichita Kansas
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Drifting
Joined: Jun 2005
Posts: 1,523
Likes: 1
From: grand prairie texas
I agree with Fatcat while you are droping the pan again to at least confirm that the rear main seal is installed in the proper direction and staggered. In that area it is too hard to tell which is leaking. It will only take you about 30 more minutes to remove the pump and bearing cap. Just my $.02
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Are you certain that a valve cover is not leaking near the rear and running down onto the pan? That is a very common occurrence. See if there is oil on the block above the pan gasket or rear main seal. If the valve covers are 'tight', there should be no oil above those areas.
Racer
Joined: Apr 2005
Posts: 259
Likes: 45
From: Columbus Mn
Another potential leak is from the oil line at the rear of the intake. That will run down the back of the block and make you think it's the rear oil pan seal just like the valvecovers.
I agree the one piece gaskets are great, but I've still had the end seal areas leak. I found I still need to add a bead of sealer around the outside after the pan is installed. If I do that no leaks, otherwise unfortunately it eventually leaks.
Some auto stores sell a dye that you add to your crankcase oil. Add it, drive the car and then pull it into a dark garage and poke around with a black light, and you can see where the leak starts.
One more thing to consider, is just re-tightening the bolts. Mine became loose after 500 miles. I wished I had threadlocked the bolts.
Good Luck.
I agree the one piece gaskets are great, but I've still had the end seal areas leak. I found I still need to add a bead of sealer around the outside after the pan is installed. If I do that no leaks, otherwise unfortunately it eventually leaks.
Some auto stores sell a dye that you add to your crankcase oil. Add it, drive the car and then pull it into a dark garage and poke around with a black light, and you can see where the leak starts.
One more thing to consider, is just re-tightening the bolts. Mine became loose after 500 miles. I wished I had threadlocked the bolts.
Good Luck.
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Drifting
Joined: Sep 2007
Posts: 1,572
Likes: 51
From: Wichita Kansas
I agree with Fatcat while you are droping the pan again to at least confirm that the rear main seal is installed in the proper direction and staggered. In that area it is too hard to tell which is leaking. It will only take you about 30 more minutes to remove the pump and bearing cap. Just my $.02
and had to redo the seal a few day later. It is easy to do. If all is dry up top then you know you need to pull the pan. If you redo the rear main make sure you apply a small amout of sealent at the seals mating ends.
Thread Starter
Racer
Joined: Nov 2005
Posts: 409
Likes: 5
From: Orange County CA
I went down to the local Kragen Auto parts and picked up the Fel Pro one piece pan gasket.. $26.99, but looks like a pretty good quality gasket and includes new oil pan bolts and lock washers..
Installation was a breeze.. remove the 2 idler arm bolts and the steering cylinder and it dropped right out.. I couldnt have done that with my 68 Camaro..I would have had to lift the engine..
I installed it dry per the instructions except for the corners by the block and torqued the small bolts down to 8 ft. lbs and the larger corner bolts to 18 ft. lbs. I felt uneasy about torquing them that much, but the gasket has reinforcements around the bolt holes to prevent it from squeezing out.
I did not pull or disturb the rear main seal as I had just replaced it and the crank and flywheel appeared to be bone dry. It looks like the old cork gasket was leaking in the corners where it meets the rubber gasket.
I will let the RTV set up overnight before I refill it and start it up.. Wish me luck..
Installation was a breeze.. remove the 2 idler arm bolts and the steering cylinder and it dropped right out.. I couldnt have done that with my 68 Camaro..I would have had to lift the engine..
I installed it dry per the instructions except for the corners by the block and torqued the small bolts down to 8 ft. lbs and the larger corner bolts to 18 ft. lbs. I felt uneasy about torquing them that much, but the gasket has reinforcements around the bolt holes to prevent it from squeezing out.
I did not pull or disturb the rear main seal as I had just replaced it and the crank and flywheel appeared to be bone dry. It looks like the old cork gasket was leaking in the corners where it meets the rubber gasket.
I will let the RTV set up overnight before I refill it and start it up.. Wish me luck..
Last edited by Corvettetodd; Nov 28, 2009 at 08:04 PM. Reason: typo
Burning Brakes
Joined: Jul 2009
Posts: 1,132
Likes: 14
From: A town SC
I went down to the local Kragen Auto parts and picked up the Fel Pro one piece pan gasket.. $26.99, but looks like a pretty good quality gasket and includes new oil pan bolts and lock washers..
Installation was a breeze.. remove the 2 idler arm bolts and the steering cylinder and it dropped right out.. I couldnt have done that with my 68 Camaro..I would have had to lift the engine..
I installed it dry per the instructions except for the corners by the block and torqued the small bolts down to 8 ft. lbs and the larger corner bolts to 18 ft. lbs. I felt uneasy about torquing them that much, but the gasket has reinforcements around the bolt holes to prevent it from squeezing out.
I did not pull or disturb the rear main seal as I had just replaced it and the crank and flywheel appeared to be bone dry. It looks like the old cork gasket was leaking in the corners where it meets the rubber gasket.
I will let the RTV set up overnight before I refill it and start it up.. Wish me luck..
Installation was a breeze.. remove the 2 idler arm bolts and the steering cylinder and it dropped right out.. I couldnt have done that with my 68 Camaro..I would have had to lift the engine..
I installed it dry per the instructions except for the corners by the block and torqued the small bolts down to 8 ft. lbs and the larger corner bolts to 18 ft. lbs. I felt uneasy about torquing them that much, but the gasket has reinforcements around the bolt holes to prevent it from squeezing out.
I did not pull or disturb the rear main seal as I had just replaced it and the crank and flywheel appeared to be bone dry. It looks like the old cork gasket was leaking in the corners where it meets the rubber gasket.
I will let the RTV set up overnight before I refill it and start it up.. Wish me luck..
When you installed the rear main, did you lube it well? If its not pre lubed before start up the, crank can burn it up if run dry. If run dry the seal is useless and most of the time will leak. m2cents
Thread Starter
Racer
Joined: Nov 2005
Posts: 409
Likes: 5
From: Orange County CA
I did lube the rear seal with assembly lube when i installed it and used RTV on the mating ends. I also "clocked " the seals so that the joining ends are not lined up with the crank and bearing cap..
I will find out tomorrow when I refill with oil and fire it up..
Good to know that even if it is/was the rear seal it is very easy to get at..unlike most cars.. I had the pan off in about 30 minutes..
I will find out tomorrow when I refill with oil and fire it up..
Good to know that even if it is/was the rear seal it is very easy to get at..unlike most cars.. I had the pan off in about 30 minutes..
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
My brother is a motorcycle mechanic, and here's a trick he uses to track down oil leaks: Clean the suspected leak area really well, and spray liberally with spray-on foot powder. You will see the oil leak the instant it starts leaking.
Scott
Scott
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
If you have to redo the pan gasket/seals, make certain that you clean the surfaces well with a solvent to get all grease/oil from them, especially the joints where the RTV is to be placed. Then put a dab of RTV in those corner joints [at the junction of the end seals and the pan rail, install the gasket over the guide pins, then the pan and bolts.
Burning Brakes
Joined: Jul 2009
Posts: 1,132
Likes: 14
From: A town SC
If you have to redo the pan gasket/seals, make certain that you clean the surfaces well with a solvent to get all grease/oil from them, especially the joints where the RTV is to be placed. Then put a dab of RTV in those corner joints [at the junction of the end seals and the pan rail, install the gasket over the guide pins, then the pan and bolts.
Ive built at least a hundred of them and twenty at least left a drop overnight!! Nothing like the one piece gasket though, no leaks since!!!
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Yeah, but I can still read my dashboard guages in my 'vette while driving 80 mph down the highway!
Scott
4th Gear
Joined: Nov 2009
Posts: 4
Likes: 0
i put a one piece in my 383 and had no problems, granted it was on an engine stand so it might be a little more difficult putting it on. however they supply you with alignment pieces for doing it in car. another thing to check is the intake manifold. i had some troubles with the end seals on that leaking. but the one piece gasket is for sure worth it. make sure you torque it down. i think its like 17lbs but i cant remember for sure. good luck
