Crankcase vacuum leak, PCV Valve replaced, how to smoke test it? 2011 2.0 TFSI

[rustmyenemy]

2011 A4 2.0 TFSI
I started having a rough idle and misfires at idle. You can hear a whine coming out the engine bay. All of this goes away when driving. ( the whine is probably still there but can't hear it from inside)

The first codes I had were:
p2279 leak in air system
p0506 rpm lower than expected
all cylinders misfire

Classic PCV valve failure right?
I replace the PCV valve with the one from Audi, my initial PCV valve was the J model and they gave me the AK version ( the car probably had the pcv and software update with the first owner).
The problem is still there, I block the hose from PCV to intake manifold and the problem goes away, this means that:
1. I have a bad new PCV, or tubes that connect to it
or
2. I blew up the rear main seal or front seal on the crankcase

Did I miss anything? What tests can I do to further diagnose where the leak is from? Does anybody know where I can plug a smoke machine to test the crankcase for leaks?

[Theiceman]

you should be able to put the smoke right in the oil filler cap if you are suspecting a crankcase leak...

someone posted a pic of the access port removed for the thrust plate underneath the car and smoke billowing out, pretty well confirms your RMS is blown out ... big job. . But i think if that was blown you would have a ton of oil in that area as soon as you took the inspection plate off...

other areas are cracked oil dipstick tube ( often happens when guys put in a dipstick but don't cut half the handle off.. so dropping the hood breaks the tube )

since you are smoking the crankcase, may as well smoke the entire intake tract and see what you find.

RPMtech should be pretty familiar with this and will probably pipe in.

[RPMtech147]

you should be able to put the smoke right in the oil filler cap if you are suspecting a crankcase leak...

someone posted a pic of the access port removed for the thrust plate underneath the car and smoke billowing out, pretty well confirms your RMS is blown out ... big job. . But i think if that was blown you would have a ton of oil in that area as soon as you took the inspection plate off...

other areas are cracked oil dipstick tube ( often happens when guys put in a dipstick but don't cut half the handle off.. so dropping the hood breaks the tube )

since you are smoking the crankcase, may as well smoke the entire intake tract and see what you find.

RPMtech should be pretty familiar with this and will probably pipe in.

This. Get a replacement oil cap from the parts store. Drill a hole all the way through it. Stick an appropriately sized barb in the cap and seal it up with epoxy or silicone. Loosen the intake tube from the air filter housing, pop it off, slip a 1 gallon ziplock bag or other thick plastic over the end of the filter housing and reinstall the intake pipe. This gives you a pretty good seal. Install your test oil cap and smoke away. Works very well and being the PCV is tied into the intake track, it also pushes smoke and pressure through all the intercooler piping. If you smoke through the oil cap, it will billow out of the air filter (Hence the plastic baggie)

Also, you can just craw under the car, if the rear main is bad enough to cause lean faults, it (the bottom of the transmission) should be covered in oil....

[rustmyenemy]

Thanks guys, just waiting on the machine and I will give an update on the results

[rustmyenemy]

Confirmed, how long can I drive with a leaking RMS and blocked intake manifold? My trusted garage only has availability in about 2 weeks. I blocked off the intake manifold connection and the car drives and idles just fine except from fumes going into cabin and having to check that I didn't leak all my oil before starting.
Can I damage the new PCV or any other components by driving like this?

[Smac770]

The PCV won't know. So instead of vacuum pulling crankcase vapors through the PCV, atmospheric pressure won't pull anything. I'd cap off the PCV tube too though; no need to leave it open to atmospheric. You could run it that way easily to cover a two week delay.

[rustmyenemy]

If I also block the PCV tube, what will happen to the fumes coming out of it? I can smell them when not moving.

[Smac770]

What crankcase vacuum/pressure are you running at idle? The normal vacuum won't be there with the IM disconnected, but you shouldn't be running positive pressure such that it pushes fumes out against ambient. Cap the tube with your hand and watch the pressure; does it increase above 0 or just sit there? When you get on the gas, the vacuum at the turbo inlet takes over and will pull positive crankcase gases generated by the engine under load.

You might instead just cover the end of the tube with a paper towel; that's what I've done when testing with the tube disconnected. Pressure should still bleed, but any oil residue will trap there rather than leak wherever.