My 00 NB miata started to oil consumption.
I could see blue smoke in the mirror after throttled above 3000-4000 rpm.
I rebuild my engine about 2000 km before.
So I made compression test -
1st cyl 140 psi
2nd cyl 145 psi
3rd cyl 140psi
4th cyl 143psi

wet compression test results -
1st cyl 149psi
2nd cyl 152psi
3rd cyl 149psi
4th cyl 150psi

It seems pistons and pistons rings are ok,car is not detonate,runs smooth, what can be a problem?

 

Did you rebuild the head? Valve guide seals leaking?

 

How much oil are you losing? Smoke indicates bad valve seals.

 

Im thinking Valve seals too.... but its good that the car is not detonate... lol

 

Yes ,I rebuild head with new elring valve seals..
It is approximate half a quart of oil for 150miles ,but it depends on driving style.
I made this upgrade too - MX-5 Unleashed - Valve Cover Internal oil air oil separator for Miata Valve cover
I have got stock PCV valve.

 

I drive 50 miles today to next town Martin for visiting visit Sturovo,1 liter of oil burned..
Sometimes a big of fog cloud created from my exhaust.
Sturovo is a great man. We were talking about miatas ,turbos. That s great to know person like him from miata.net forum and find him in the same state in next town (especially in Slovakia where miata is very rare car).
He also saved me and my miata ) with oil fill up.

I check spark plugs -first three are ok, 4th is totally black and oily. Compression test is still ok. I must to dismantle head - hope it will be gasket,not piston or rings.
But it is seems that its finally right time to exchange problematic coldside supercharger mp62 setup for turbo with Sturovo helpful.

 

It seems ,that I just resolve a problem with oil burning.
A friend of mine advise me to install oil catch can between PCV valve and vacuum line distributor,and on the other side of valve cover ventilation (hotside) simple little air filter. After about 2 kilometers my miata stopped to blue smoking .
It seems that the oil was collected from valve cover ventilation in the back side of intake manifold under the supercharger. Internal of supercharger and throttle body was oily too.
I have got stock pcv valve with some restriction plug in the hose - it was included of coldside supercharger kit (FFS).
Is it correct mounted - valve cover ventilation through simple little air filter (hotside)
and oil catch can between pcv valve and intake?
I used only cheap ebay oil catch can.
Is it necessary to install PCV valve from 323 turbo?