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new heads and now oil leak....ventilation question

4K views 22 replies 8 participants last post by  troutman2 
#1 ·
Hey Guys-

I recently swap heads from the old swirl port to the Vortec heads and also changed to E-brock RPM intake. Since then, I have a noticeable oil leak. I first thought it was valve covers, distributor gasket, or rear main. It doesn't appear to be any of these, but more so coming from the breather on the valve cover.

I don't believe it's the rings (less than 10k on the shortblock), so my next question is if I have the ventilation setup properly. I am running a PCV valve on the driver side, and breather on the passenger. There is an additional plug on the passenger side as well that seems to be old and maybe a bit deteriated. In looking at the pics below, is that plug needed,and if so, could it being old be causing the blow by? Could I put an additional breather there?



 
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#2 ·
Did you check for vacuum at the pcv valve. it wont work if there is no vacuum. Also are you sure it is not leaking out of the back of the intake. What did you use for sealing the front and back of the intake. If you used gaskets instead of rtv this could be your issue
 
#8 ·
So it looks like the valve cover does have baffling under the breather. I also verified the breather itself is opened as mentioned in an earlier reply. Any other ideas of what to check next?

As you can see, it leaves a noticeable puddle on the ground. This is after a 1hr drive and sitting overnight.





 
#9 ·
If you had that much oil after an hour of running and it was all coming from the breather I'd think you'd smell it burning on the headers.
Get a small mirror and look at the back of your motor where the valve covers are and the back of the intake.
After a drive run your finger across the same area.
Oil leaks are hard to find.
 
#10 ·
I can definitely smell it. I did exacly what you said with the mirror lastnight. The intake and distibutor area are dry as a bone. It was wet behind the valve cover and looks to be leaking down from the passenger side. It just seems like an excessive amount to be coming out of the breather.

Is it worth while to just replace the PCV and breather?
 
#13 ·
S10 Racer said:
I would be curiuos what it would do if you switched valve covers from side to side. Put the PCV valve on the passenger side and the breathers on the drivers. This would orient the baffles in the valve covers differently.
Interesting thought....it's just odd that the leak appeared after doing the head/intake swap. The heads prior to this were the ****ty swirl port heads and an Ebrock Performer intake.
 
#17 ·
Well I pulled the passenger valve cover and verified there is a baffle. I did notice some excess oil on the back side, so I am hoping maybe the gasket just wasn't sealed correctly. As mentioned these are the reusable rubber kind, and are kind of a PITA to put on, as you have to stretch them a bit. I got it back together and cleaned it up, but couldn't do a test run. I am hoping this was the issue, otherwise I may start leaning towards the rear main =(

 
#18 ·
cdminter59 said:
When you pull the valve cover check underneath the breather cap that is where the baffle should be. It is a metal shield to keep oil from splashing up to the breather cap. Check out Summit racing for some baffled grommets if not baffled. http://www.summitracing.com/parts/MOR-68775/

Should the grmmet for the PCV valve be baffled? I believe it's just a normal grommet that is in there currently.
 
#23 ·
Had oil and coolant leaking on buddy's 350 engine after swapping from smogger to vortecs. Finally found it to be the block dowel pegs that position heads was sticking up too high and w/ head torqued it caused the leaks. Had to remove that head, grind/ hacksaw down some and reinstalled w/ another new gasket and problem fixed.
 
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