Oil leaks

[khryslerkid]

Some day I'm going to install a fitting and gauge and measure crankcase pressure. I've often wondered if there is sufficient flow through that itty-bitty pcv hole to create vaccum in the crankcase. And conversely are breathers sufficient to neutralize crankcase pressure.

Really all you need to do is lay a piece of paper over the valve cover hole. If it sticks you have negative pressure. Only way to achieve this is to create vacuum in the crankcase from the intake manifold. Factory uses a hose from the carburetor base to the valve cover. One valve cover has the hose with a pcv valve and the other valve cover has a breather. Without vacuum in the crankcase, pressure can result in oil leaks that normally wouldn't happen.

Are you sure it's not the crankshaft seal?

 

[Aron Gleason]

Really all you need to do is lay a piece of paper over the valve cover hole. If it sticks you have negative pressure. Only way to achieve this is to create vacuum in the crankcase from the intake manifold. Factory uses a hose from the carburetor base to the valve cover. One valve cover has the hose with a pcv valve and the other valve cover has a breather. Without vacuum in the crankcase, pressure can result in oil leaks that normally wouldn't happen.

Are you sure it's not the crankshaft seal?

The crankshaft seal has been replaced. So its not leaking there. I can see it leaking at the passenger lower corner of the timing chain cover.

 

[Aron Gleason]

So if I get a pcv valve. Can I still leave the baffle in the valve cover? Would i run the hose to the front port on my 950 quick fuel carburetor next to the port I use for my vacuum gauge? Or would a catch can be a better place to run the hose to?

 

[Billccm]

Mine seeps at the area @Aron Gleason describes. Some people say it's caused by the alignment at the pin to the timing cover. I tried blue gaskets, cork gaskets, Toyota FIPG, gaskets plus Toyota FIPG, reaching up inside the timing cover and packing a bead of Toyota FIPG, external bead of Toyota FIPG, and nothing stops the seeping of oil.

 

[dvw]

Take a $10 Harbor Freight regulator. Plug the breathers and the pcv. Connect the regulator to the dipstick tube with the presure set to 3-5 psi. Spray the area with soapy water. You'll easily see wher the leak is. I use this method all the time on motors and transmissions. Never failed to find the leak.
Doug.

 

[Aron Gleason]

Take a $10 Harbor Freight regulator. Plug the breathers and the pcv. Connect the regulator to the dipstick tube with the presure set to 3-5 psi. Spray the area with soapy water. You'll easily see wher the leak is. I use this method all the time on motors and transmissions. Never failed to find the leak.
Doug.

I dont need to go through all that, I can plainly see where its leaking.

 

[Aron Gleason]

Really all you need to do is lay a piece of paper over the valve cover hole. If it sticks you have negative pressure. Only way to achieve this is to create vacuum in the crankcase from the intake manifold. Factory uses a hose from the carburetor base to the valve cover. One valve cover has the hose with a pcv valve and the other valve cover has a breather. Without vacuum in the crankcase, pressure can result in oil leaks that normally wouldn't happen.

Are you sure it's not the crankshaft seal?

Interesting, that does make sense though.

 

[gkent]

I see a lot of used catch cans for sale. Must be a reason !!!

 

[Bird 426]

If you can see exactly where the leak is, the only thing that I can add is. Pull your oil pan, run a straight edge down front to back, clean everything and install a new gasket set. PCV valve isn't a cure all, but certainly can't hurt. From your comments, seems like you may not want to go this route, no brainer for me.

 

[Aron Gleason]

If you can see exactly where the leak is, the only thing that I can add is. Pull your oil pan, run a straight edge down front to back, clean everything and install a new gasket set. PCV valve isn't a cure all, but certainly can't hurt. From your comments, seems like you may not want to go this route, no brainer for me.

Im thinking maybe a new oil pan.

 

[dvw]

I dont need to go through all that, I can plainly see where its leaking

If you know exactly where it's leaking then it's an easy fix. But what if it's in the corner of the timing cover and the pan? Which gasket is leaking? You didn't mention if it was a BB or a SB. The timing cover bolt holes at the bottom of the BB are not very deep. If the bolt is to long it will bottom in the block before it tightens the cover. It's such a small amount you wont see it. Since you had both components off could be either one. And no, a larger cam will not create addtional crankcase pressure. The only way that can happen is poor ring seal, hole in the piston, leaking head gasket to the crankcase area.
Doug

 

[Aron Gleason]

Its a 440, and i never took the oil pan off. Just water pump housing and timing chain cover.

 

[BSB67]

When you added the repair gasket, did you remove the old gasket?

 

[Aron Gleason]

When you added the repair gasket, did you remove the old gasket?

Yes, I cut it out and made sure the pan and cover was clean

 

[69Bee]

So if I get a pcv valve. Can I still leave the baffle in the valve cover? Would i run the hose to the front port on my 950 quick fuel carburetor next to the port I use for my vacuum gauge? Or would a catch can be a better place to run the hose to?

PCV valve in one valve cover and a breather in the other valve cover. If you have 2 breathers in both already, you will need to take the breather and grommet out of one and install a PCV valve with the proper grommet, PN#3751510. If your breather grommet is old and hard (that's what she said) then a new breather grommet is PN#2946079.

 

[Bird 426]

Guess that it shouldn't leak then, you've done everything right.

 

[Aron Gleason]

PCV valve in one valve cover and a breather in the other valve cover. If you have 2 breathers in both already, you will need to take the breather and grommet out of one and install a PCV valve with the proper grommet, PN#3751510. If your breather grommet is old and hard (that's what she said) then a new breather grommet is PN#2946079.

Im now told i dont need to get a pcv valve since the problem is either the pan gasket being compromised or the rings maybe worn.

 

[Aron Gleason]

Guess that it shouldn't leak then, you've done everything right.

Well according to a so called friend, im not a mechanic and shouldn't be doing anything on the motor lol. He obviously forgot that I changed out the cam and lifters and timing chain without anyone's help. And he even had the gall to say he would believe the salesman at Summit racing on a set of single spring valve springs for his motor that has a .620 lift cam when I told him he needs dual spring valve springs.

 

[dvw]

Im now told i dont need to get a pcv valve since the problem is either the pan gasket being compromised or the rings maybe worn.

If you didn’t have excess crank pressure before the cam swap you shouldn’t have any now either. I was just pointing out causes of excessive crankcase pressure. So you have a few paths to a correct repair. Make sure the lower timing cover bolts aren’t too long. Leak check as suggested to see exactly which of the two gaskets are leaking. Or replace just the pan gasket and hope that’s it. Last replace both the timing cover gasket and the pan gasket. Your choice.
Doug

 

[1967coronet]

Yes , install a pcv valve with a hook up on the intake. Breather on the other cover.
You will not like to hear this, you need to pull the pan and timing cover again.
Clean it all up and install new gaskets.
Make sure the timing cover one is on the pins, I've seen them slip off one side.
Little bit of hightemp on the corners were the two gaskets meet.