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Discussion Starter · #1 ·
I'm getting a major oil leak outa my valve cover breather. I was told that it's probably a pcv valve plugged. Anyone here agree? I dunno what to do it leaks like 4 quarts out between oil changes.

77 Chevy heavy half, fulltime 4X4, np203, TH400, 400ci., Edelbrock 650cfm carb w/electronic choke.
 
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Discussion Starter · #2 ·
If you are loosing that much oil, I would be thinking more along the lines of bad rings. I would run a compression check on the engine. Under normal conditions you can completely remove the pcv valve and not get any oil out of the valve covers.

 
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Discussion Starter · #3 ·
If you completely removed the pcv valve then there would be nothing there to block it right? Anyways it's been to the shop and they told me the valve cover gaskets and the seals and even the rear seal was fine. Hope that helps. It seriously is leaking it all out of the breather. My mechanic thinks the engine might be getting "tired". It's only got 76,000 miles though, but it is 25 years old. The breather was added when the edelbrock carb was put on back in 92'

77 Chevy heavy half, fulltime 4X4, np203, TH400, 400ci., Edelbrock 650cfm carb w/electronic choke.
 
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Discussion Starter · #4 ·
You are correct that if the valve is removed there is nothing to block it. I probably should have worded it differently, but my point was that there shouldn't be oil comming out of the breather at all wether you have a blocked pcv or no pcv. The only thing that I can think of that will blow oil out of the breather would be bad rings or a blown head gasket, and either one should result in a less than ideal compression test. Hope that this has helped.

 
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Discussion Starter · #5 ·
BTW it doesn't burn any oil. So maybe that eliminates the worn rings?

77 Chevy heavy half, fulltime 4X4, np203, TH400, 400ci., Edelbrock 650cfm carb w/electronic choke.
 
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Discussion Starter · #6 ·
I'm pretty sure a faulty PCV valve will do that. Replace the valve, it's a cheap part. Let us know if it fixes it or not.

Shawn
87 K5
few mods

 
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Discussion Starter · #7 ·
Yep, put on a new PCV valve first and HOPE that clears it up. Otherwise, you have more pressure than the valve can eliminate which means "blow by", never good...

Bad Dog

85 K30 CUCV, 350 TBI, TH400, NP205, D60/C14FF locked 4.56
Soon: 4" lift, 40" tires, massive cutting, shorter wb and rear overhang.
 
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Discussion Starter · #8 ·
Other than blowby, your drain hole are'nt clogged up are they? It could be getting to much oil up top and not draining down quick enough because of sludge or somthing!!

It's as close to a 1ton as it can get and still be a jeep!!! Gotta love it!!
 

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What kind of vavle covers??????those cheap chrome jobs??It maybe a baffle problem,or a lack of the proper type of baffling in the cover that lets the oil blow out.70's chevy v8's only had the fresh air into the crankcase on one side and the pvc on the other side.Do you have a breather on both side's??If so the pcv system really does not work,it kind of short flows in the one cover,also do you have a factory pcv vavle?Some of those aftermark ones are junk,the flow rates are not matched to the engine

 

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Several good points have been brought up /wwwthreads_images/icons/smile.gif

This is what I would do pull the hose off the PCV and start the engine stick your finger over the end of the hose and make sure there is vacuum there, with the engine still running shoot some carb cleaner up the hose (to the carb) this will help clean out any build up that might be in there, If it dosnt make it run like crap for a minute, then that is the problem, there is no suction.
As long as it does make it run crappy for a second, then replace the PCV (they are like $5 max)
Then see what happens maybe it will stop.
Also, that type of breather almost always leak some I would look for a different one.
If it has ALWAYS leaked those might be crummy valve covers also.

Scooby Dooby Doo !!!
 
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Discussion Starter · #11 ·
Ok, I will check it out and let ya'll know.

77 Chevy heavy half, fulltime 4X4, np203, TH400, 400ci., Edelbrock 650cfm carb w/electronic choke.
 
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Discussion Starter · #12 ·
I wish I had a digital cam. Maybe I can borrow one....

77 Chevy heavy half, fulltime 4X4, np203, TH400, 400ci., Edelbrock 650cfm carb w/electronic choke.
 
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