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Help! Yet another PCV question

2K views 11 replies 6 participants last post by  grand-pooba 
#1 ·
Sorry guys I've read through a number of PCV threads here and still have questions.

I have a new Ford Racing 5.0 crate motor with just 500 miles on it. I have an oil leak that appears to be coming from inside the trans bell housing (AOD) and drips out of the inspection plate at the bottom. Not a big leak but drips.

I have a hose routed from the oil filler tube (it had a nipple/spout on it already) to inside the air filter element. That means no vacuum leak. I figured that this would draw from the crankcase any fumes and moisture.

There is no PCV. I'm using a Holley EFI TBI system. It does have a PCV port that is blocked off.

Is it possible that there is enough preasure inside the crankcase to be forcing oil out the rear main? And if so, would replacing the sealing oil filler cap with one with breather holes resolve the issue?

I took a picture of it and attached it here. Really sorry for yet another PCV post...
 

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#2 ·
Sounds like you've nailed it. Normally this happens with boosted engines, but if you have no way to vent to crankcase I can see why it would be a problem on any engine.
 
#4 ·
Early on with mine I played with different (non-vacuum) means of venting the crankcase. At one point I had the PCV valve plumbed into the intake air tubing downstream of the maf but upstream of the throttle body. Within a week I had both the front and rear main seals leaking on a fresh build. Set up the stock PCV configuration and both leaks immediately disappeared.
 
#6 ·
those rocker covers are for an EFI setup, that is why there is no provision for a PCV valve, the pcv valve is on the lower intake on a efi setup.

That hose on the filler is for the crankcase to draw in fresh air from the air cleaner when you have a PCV valve on the opposite valve cover pulling a vac on the crankcase.

You can have a hole drilled into the cover to except a suitable PCV valve and grommet that will connect to constant vac source on the carb, usually below the TB.
 
#12 ·
While we are on oil leaks, Having same problem. 7 qt oil pan thinking of running 6 qts, think that would help? I was running free flow vent pipe and just put pcv valve on. To dam cold to go out and play till it warms up,(couple days) I believe between the two changes I feel strong that I have fixed it, time will tell.
 
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