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Discussion Starter · #1 ·
Quick question here...I replaced my valve cover gasket a few weeks back, by taking the utmost time and care, I managed to seal it very well. No leaks for the past month. However, oil seems to be leaking out of the top of the valve cover, from the breather element on the back of the valve cover. I also had a leak from my dipstick. I removed and degreased both parts, and the used some black RTV to seal them. Hopefully they'll hold.

Onto the question:

My oil pressure reads about 20-25psi at 1500rpm...
What would cause oil to leak from the top of the valve cover?
Too much crankcase pressure would be my guess...but I replace the PCV valve a little while back, and when I remove it, I feel a good bit of vaccuum.
 

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You could have good vacuum at idle, but enough blowby at highway speeds to overwhelm the PCV. The breather at the rear of the valve cover should be connected to the air cleaner by a fairly fat hose. Is that the case, or is there just a little air filter there?

One time, as a test, I made a little plastic manifold to allow running two PCV valves in parallel. It didn't make any difference in my case, but you might try it.
 

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Discussion Starter · #3 ·
I've got a little chrome breather the I bought from autozone...
The original air filter is gone. I've got a small aftermarket filter on the carb. I have all the emissions stuff gone or disconnected.

Tim
 

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[ QUOTE ]
Could you elaborate on the puke can?

[/ QUOTE ]

Puke = Throw up.

Can = Something to catch it in.

Click on the graphic...It's for a 4.0 engine but you'll get the idea...



Oh, and yes, I remember road draft tubes. I've seen 'em suck water in and destroy engines back when Noah was building the Ark.
 

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I did pretty much the same thing years ago, before I rebuilt the 258. Except I used a quart-sized plastic oil jug, a breather, and some plastic fittings.

- Run elbow out breather hole at rear of valve cover.
- Run heater hose slightly downhill to T-fitting.
- Bottom of T-fitting goes to oil jug.
- Top of T-fitting goes to breather.

I stuck mine under the brake booster. Worked great.

Good luck,
Pete
 

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probably is a blowby issue, but ill tell my little tale anyway...

had an '76 chevelle ss w/a '74 350 while in college, ran great for a year after i put it together, the one day driving down main st. keene, nh...it proceeded to lay out a smokescreen that gen. patton would've been proud of...freaked me right out, thought i blew it up or sum such...nothing obvious under the hood, and restarted fine...??????...got it home the next w/e and my bro said "lets look under the valve covers"...sure enough, i had a stuck lifter that, unfortunately, would pump a little squirt of oil DIRECTLY into the pcv valve on every stroke till it loosened back up!!

i liked that car too, but its usefull life was over within a month (i couldnt afford the oil!/ubbthreads/images/graemlins/grin.gif), sold it to a buddy for parts and moved on

your problem is more than likely just blowby, but figured id relay this tidbit to ya, mine burned the oil off just cause of the position of the stuck lifter, one valve either way and it may have just puked out through another spot

good luck
 
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