What have we done? We changed the air intake to highflow cone filter set up and put a filter over the PCV valve. Over the last 4 months the engine ran great but has been leaking oil at every seam...

Today we went to start it and it made several large popping sounds and smoke came from lung #2...

Is it time for a long block transfer? or do we just have some silly vacuum problem????

Please help we just got this puppy painted up and have bilsteins waiting in the closet of endless GT parts...

No doubt about it, vacuum problems suck.

Or don't, as the case may be.

What's this about a "filter over the PCV valve?"

Confirm that your crankcase ventilation system is free and clear and that you have a bit of negative crankcase pressure at idle. (I've measured the vacuum to be around 1.5 inches of water at idle.)

Also confirm that you have good, dry, clean ignition components. You might have a case of "crossfire," which occurs when sparks jump around in moisture 'n grime that sometimes collects on (or in) a dist cap.
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Don Foster (near Cape Cod, MA)

The filter over the PCV was a small air filter to substitute for the fact that we no longer had an airbox to run the outlet of the PCV into... (When we put on the cold air intake we lost the air box.) I suspect this has something to do with my problem because I no longer have vacuum at the PCV, the truth is my car probably never did because the air box that we removed was pretty broken.

What's the proper thing to do with the outlet of the PCV valve when you switch to a cold air intake? How do you maintain vacuum?

P.S. My backfire was in the intake... what does that tell me?

I suspect that the ventilation hose connected at the airbox experiences a very slight vacuum, which is created by the pressure drop across the air filter as the engine breathes. But now, yours not only doesn't have that slight vacuum, it instead may have a slight positive pressure. This slight pressure can occur from the restriction caused by the extra filter -- the pressure increase will depend on the flow rate.

The "PCV," as you call it (it's really called the "flame trap"), has a small vacuum line, about 1/4" OD, that connects to the top of the "Y" fitting. The other end attaches to a small brass nipple on the intake manifold. That hose and the fitting are notorious for plugging with carbonized varnish, blocking the vacuum.

Be absolutely sure that the oil spearator (aka "breather box") and the flame arrestor (inside the flame trap) are clear. If either plugs up (not uncommon, particularly on a car that had neglected service) then your crankcase will develop enough positive pressure to blow oil past all the seals, and even pop a seal outta its housing (BTDT).
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Don Foster (near Cape Cod, MA)

Thanks Don, I appreciate your input.

Looks like we have to go back to the stock setup before we reek havoc on our engine.

Thanks again!

Zac