As I already mentioned in the 1-st part of CCV test – if CCVV don’t close, the oil consumption will be increased.

But even more critical damage – CCVV is not airtight. This time a little more about this exact problem.


Possible defects:

a) the membrane is broken (ruptured);

b) the membrane is not airtight around its perimeter.


To identify this defect:

a) take off the decorative cover of the engine;

b) with finger close/open the CCVV ventilation hole.


Here is the video:


What CAN NOT happen, while performing this procedure:

a) the performance of the engine can not change;

b) no noise can appear or disappear;

c) integrators cannot change significantly (MSD80: ../F5/F6).


In the picture: integrators marked (MSD80):

If AT LEAST ONE of symptoms, mentioned before, appears – CCVV is not airtight. It’s a critical problem and has to be repaired immediately!


If CCVV is not airtight:

a) the engine will shiver, will stall, the misfires will be present;

b) offset type LTFT will be incorrect or will not be confirmed at all (they will be 0.00 mg/stk);

c) the injector corrections in idle will be incorrect (and, possibly, also for Stratified charge).

Coming back to the video – it can be clearly heard, how the noise of the engine changes, when the vent hole is closed. It is not acceptable! Conclusion – CCVV is damaged!

In an especially dramatic situation, both offset type LTFT and integrators will be 0 (the engine would switch to open loop mode) and will not change. Possibly, the performance of the engine will be such uneven, that you will not be able to say if the situation betters up when closing the CCVV vent hole.

Of course, the smoke test will help in this situation. One more simple method: disconnect and close the pipe, which goes from CCV to the inlet manifold.

Close the pipe, marked in the picture. CCV outlet can be open to the time of the test.

Start the engine several times. If the performance of the engine normalizes – the air suction place has been confirmed – CCV defect is confirmed.


And finally – the last method.

If you have a manometer with a pump:

Connect the pump to the CCV ventilation hole. Pump the pressure up or suck out the air. The pressure/thinning has to stay unchanged. If the contour is not airtight – CCVV is damaged and has to be replaced immediately!