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Chasing Oil Leak

ksurfer2

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I have been chasing an oil leak on my 440 (1972 block). It appears to be coming from somewhere on the passenger side of the engine and dripping onto the exhaust manifold/downpipe towards the rear of the engine. This is causing a bit of smoke as it burns off on the manifold. I have replaced the valve cover gasket twice with silicone gaskets to no avail. It has the stock stamped valve covers. Is there somewhere else I need to look for the leak, or take another shot at the valve cover gasket? Another type of gasket? I did not use any gasket sealer.
 
Is your valve cover warped? Bolt holes divoted from torquing?
If you are 100% on the valve cover, it could be the corner of the intake where it meets the head and valley pan. Or, the rear top of the block is an oil pressure sensor but that is usually on the driver side. But I think there is a pipe plug in the pass side gallery as well. Get a mirror and light and take a look.
 
Just throwing out another possibility that happened on mine. The oil fill on the valve cover leaked slightly dripping down to the exhaust and I wound up doubling the seal and that stopped the weep.
 
Just throwing out another possibility that happened on mine. The oil fill on the valve cover leaked slightly dripping down to the exhaust and I wound up doubling the seal and that stopped the weep.
I am also supporting this one. Sending unit leaks are to far back it drip on the exhaust manifolds normally.
 
Maybe wash it REALLY good with engine degreaser & drive it for 10 miles, then get out the mirror and start looking really close? Oil can be hard to track down once it gets everywhere. My first guess would be valve cover slightly bent if you're running stock valve covers. Maybe silicone that whole side and/or try to straighten it if you're sure it's from the valve cover.
 
Sounds like the back corner of the valve cover. That's a known place for it not to seal if over tightened. Use a white paper towel and dab it around just under the cover. It will show on the towel.
 
I had the same problem in the same place after replacing the cam. I found RTV sealant on the Mopar Performance covers when I removed them and soon found out why. That was the ONLY way I could seal that right rear cover.
 
Plug the breather . Feed low pressure air into the PCV fitting in valve cover. I use my leak down tester turned down enough that I can stop the flow of air with my thumb. Air it up and watch. You'll find the leak in less than a minute. Oil will ozze from the leak point.
Doug
 
I have been chasing an oil leak on my 440 (1972 block). It appears to be coming from somewhere on the passenger side of the engine and dripping onto the exhaust manifold/downpipe towards the rear of the engine. This is causing a bit of smoke as it burns off on the manifold. I have replaced the valve cover gasket twice with silicone gaskets to no avail. It has the stock stamped valve covers. Is there somewhere else I need to look for the leak, or take another shot at the valve cover gasket? Another type of gasket? I did not use any gasket sealer.

What heads? Factory, or aftermarket aluminum?
 
I had a similar issue, VC gaskets, changed covers then went cast aluminum also. Well it was a piece of casting flash on the top of the head where the VC gasket sat, did not see it until I dressed the surface with a stone, worth a look at least.
 
Plug the breather . Feed low pressure air into the PCV fitting in valve cover. I use my leak down tester turned down enough that I can stop the flow of air with my thumb. Air it up and watch. You'll find the leak in less than a minute. Oil will ozze from the leak point.
Doug
Dag good replies on all these above !
 
So I spent the afternoon working on this. Took the valve cover off and found the old cork cover gasket to be in pretty rough shape and saturated with oil. I replaced it with a rubber over fiber gasket. I used weatherstrip sealer between the gasket and the valve cover and let it set while I thoroughly cleaned the gasket surface on the head. Applied RTV gasket sealer to the gasket on the head side. Lightly torqued the bolts down and made sure none were bottoming out in the head. Started the car and after a few minutes, smoke started again from the exhaust manifold. I cannot see any oil coming out of the valve cover. Smoke originated about mid way down the block. Came up from the front side of where the manifold led to the down pipe. I have a short video, but it doesn't show much. What is my next step? Oil on the dipstick looks clean so I don't think there is a head gasket issue....could that cause the issue anyway???? Would it be worth while to pull the plugs to see what they look like and do a compression test on each cylinder? Could an issue in the bottom end even cause this???? I am stumped and not really sure what my next step is. I am considering pulling the exhaust manifold to see if I can get a better idea of where the oil could be coming from.
 
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If you had aired it up you would have already found it.
Doug
 
If you had aired it up you would have already found it.
Doug
OK....you were right. If I had listed to you the first time, I would have saved myself a bunch of agrevation! The trick with the coke bottle taped to the end of a hair dryer was brilliant. Of course my wife was a little skeptical while I was duct taping the end of a coke bottle to her zebra striped hair dryer! Pressurizing the crank case quickly revealed the trouble spot. I turned out to be an issue with a valve cover bolt. Replaced the bolt and now all is well. It appeared the leak was coming from the rear of the engine, but the issue was actually the bolt at the front of the engine. I guess the oil ran down the head before dripping onto the manifold!

Next time....I will listen the first time!
 
Plug the breather . Feed low pressure air into the PCV fitting in valve cover. I use my leak down tester turned down enough that I can stop the flow of air with my thumb. Air it up and watch. You'll find the leak in less than a minute. Oil will ozze from the leak point.
Doug

Work/How about a rear main seal , if that is where the leak is ?
 
The trick with the coke bottle taped to the end of a hair dryer was brilliant.

After living in Mexico for a few years now and watching how they do things around here, I have kind of learned to use the material on hand. I am very pleased you found the source of the leak.
 
Work/How about a rear main seal , if that is where the leak is ?
Look up with a mirror. If it's the rear main the oil will be coming out in front of the crank flange.
Doug
 
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