Engine: Oil Leak Stop Products

[Jan Brunvand]

The 259 V8 engine in my '53 Starlight Coupe has a persistent oil drip that seems to me beyond what should happen, even with an old, but thoroughly overhauled, engine. When I park in the driveway after a cruise, I leave behind an oil stain about the size of my two hands. Parked in the garage for a while, there does not seem to be as much of a drip. My mechanic--and as a non-technical person I must rely on him--so far has not found an obvious source of leaks. He will look again when I take the car in to check the fluid levels in the master cylinder and auto transmission. I'm pretty sure the stuff leaking is oil, not another fluid. In the meantime, I wonder if anyone could advise me of the possible value of "Oil Stop Leak" products like Blue Devil or Bar's Leaks. Online comments range from rave reviews to warnings of dire results from using these products. Is it worth a try for my car??

[1954khardtop]

I have used stop leak products as a temporary fix on a beater car I was trying to get a few more months out of, or one that was going to be taken down for an overhaul soon. They work by softening and swelling the rubber seals. They don't discriminate between the leaky seals and the good seals, so the good ones are swelled and softened, and soon wear out. They don't do anything to help leaks at paper or cork gaskets.

[thunderations]

Are you sure it's not just drips from the draft tube?

[E. Davis]

OP said it was a recently overhauled engine so that much oil out of the draft tube would indicate a lot of blow by that shouldn't be there wouldn't it. Sounds like an improperly installed rear main seal during the overhaul to me.

[RadioRoy]

It could be transmission fluid also. The OP should really map out where on the ground the stain is relative to the plan view (overhead) view of the car. Then the mechanic can go from there.

What color is the "stuff" that is leaking?
How does it smell?

I completely agree with NOT putting in any stop leak products. They will only cause more trouble later.

[ddub]

Put a big chunk of cardboard under it and you may be able to locate the source of the leak.

[kmul221]

My son a licienced heavy duty equipment mechanic calls those products "mechanic in a can " & forbids me using them.
They never made a Studebaker that didn't leak one kind of fluid or another ! Trying to get them all will become your mission in life with no end in sight .Between rust & oil leaks they will drive you over edge !

[Corvanti]

no on the engine oil stop leak. also no on tranny stop leak.

the only "stop leak" i've had temporary success with is Bars Leak for the cooling system. but just for keeping the vehicle on the road until i can get a-round-tuit.

[jackb]

excuse the old reference.... but several (many) years ago, a Turning Wheels' issue highlighted the 59' Larks. One picture showed brand new South Bend police cars in a row. Each car had an oil stain underneath about your described dropping......I sometimes use a used aluminum cook pan for oil...

[altair]

I just assembled a 259 and installed the oil pan gaskets, I had the engine upside down so the job was relatively easy. The pan cork end gaskets are somewhat longer than the space provided and it is common to cut the excess off to make an easier fit. These gaskets are cut to be compressed for a very tight fit. If they are cut they will not seal. Additionally the front cover with the aluminum spacer must be loose before the pan is tightened and then tightened up against the oil pan. There are two small cork bits that must be inserted under the rear cork, they must be driven/pressed in place as they are very tight. The rear main seal is almost fool proof and can only go in one way.

If the oil pan and front cover gaskets are installed properly they are almost leak proof.

An alternate leak can come from the valve covers and migrate down the block in an undefined pattern, this should be easy to spot. The gaskets should fit firmly in to the valve covers for easy installation. You still could have excessive crankcase pressure from a plugged breather, as this is a recent rebuild I would not suspect excessive blowby.

[BILT4ME]

I just went through a re-seal on my 59 Lark 259.

I discovered that the valve covers have started leaking near the back of the heads. Since I can't buy just the VC gaskets without getting the whole kit, I used an addition to mine.

A "new" product called "The Right Stuff" (black version ONLY) is designed as oil resistant, temperature resistant room temperature vulcanizing, sealant that can be placed in service immediately following an assembly. It cures in 5 minutes (unlike silicone caulk) (This is NOT Permatex Ultra-Black)

This has solved my new leak.

The front main seal on mine was replaced with a lip seal. The original design will still allow oil to drip out the front (felt seal with a lip designed to "pump" oil)

Yes, I still get a silver dollar sized spot under my draft tube, but I know I have lots of blow-by. Then I get the random coated with oil drips from the wind blowing the oil back under the car.

If a Stude stops leaking oil, it's out of oil.

[E. Davis]

Don't forget to check the distributor gasket. Mine was leaking excessively and running down the bell housing to the ground. Sneaky leak to detect because it makes you think its coming from somewhere above it.

[Jan Brunvand]

Many thanks for good advice. I will definitely NOT use any oil leak stop product, but will map the drips on cardboard and check out each place mentioned in posts. How I wish I had taken auto mechanics instead of Latin in HS! The "stuff" is brown, the color and transparency of coffee, no cream, and it has no odor that I can detect. I scooped up a little vial of it from a fresh drip. I'm thinking of making a T-shirt decorated with oil drips and the text "If a Stude stops leaking oil, it's out of oil." I also appreciate the comment "Trying to get them all will become your mission in life with no end in sight."