Thick white or grey smoke ONLY at WOT on N52?
 

I'm at a loss at what it could be at this point.

No idle issues. No driving issues, as far as I'm aware.

If I go WOT, or really typically 4k rpm or above, I will get a thick white cloud of smoke. The moment I let off and just drive normal, everything is fine.

I do have oil consumption that feels worse than it should be and I replaced the CCV hose at the back of the manifold as I at first thought that could be an issue; noticed 'fresh' oil on the intake manifold gaskets.

I've also considered the CCV itself to be bad, so I did that nifty 'check the oil cap while the car is running' trick, but I have zero issues opening it.

Any ideas at this point? I'm nearing 180k, so SOMETHING must need changed on it, but I just don't know what.

Seems like oil is blowing past a gasket. Maybe the valve cover gasket.

Check your oil isn't overfilled.

I had a car purchased used from a stealer (not a BMW) and they'd overfilled the engine by a lot. At high RPMs, the crank whipped it into a froth and the froth got burned in the engine via the CCV. Only happened at high RPM/WOT. (In case you're wondering, they "fixed it" but denied it had been overfilled. I had a picture of oil almost an inch over 'full' on the dipstick, but SM just shrugged.)

Not saying this is what it is, but that sounds really characteristic of the famous E46 oil control ring problem. I've even had an E46 and had the exact same symptoms of dirty white smoke coming from the exhaust on WOT only and had major oil consumption. I know it's said that oil burning is blue smoke but its not always the case for whatever reason. Smell the smoke does it smell like oil?

Oil isn't overfilled; I actually get the low oil warning once or twice prior to an oil change.

I've replaced both VANOS solenoids and checked the lower VANOS filter (looked new; AC line blocking top filter).

I'm assuming it's a seal or gasket that's causing this, but I'm not 100% sure on which one.

At this point, I'll see about doing a DIY smoke test and go from there.

Ever sort this out? Having the exact same problem on my 530.

I ended up replacing the valve cover gasket as in the very back on the passenger side, there was some oil leaking. Did it fix it, not 100% sure but it obviously wasn't helping.

I still don't go WOT as my transmission is shit, but going above 4k in 'sport' mode doesn't cause the smoke anymore.

Thats funny because I just noticed mine was leaking when I did my ofhg. Im also at 180k.