S-Prihadi

Gents,

It came to my mind this information can be helpful for those wanting to troubleshoot the knocking issue of the VVT/Phaser aka CAMSHAFT VARIABLE SPROCKET.

So while my engine is healthy, I am also keeping this as a reference, take it as a Waveform Reference of a known healthy engine if you will....in scope speak.

The Xentry have special VVT logging of 120 seconds, but you need fast C4 unit from like Benz Ninja , which is 7.14 data points per second.
What I expect to see if my VVT is worn out and shake-shake beyond certain degrees, that is where the loud Knock-Knock sound will appear.
The phaser internal moveable vane will hit the cavity end stops.

No other scanner than Xentry has this menu. Not Autel, not Launch, not Xtool or others I know of. Must be Xentry.
OpenPort 2.0 Xentry PassThru is too slow, so I do not reccomend using that.


I never ever logged VVT/Phaser from engine DEAD to engine CRANK and then IDLE. So this time I did so.


First you must know what is your camshaft adaptation, so that you do not get baffled why there is a small degrees difference between ACTUAL and SET POINT, even when engine is OFF/DEAD or when running.
Below is mine :




Here is the capture. 1 second is 7.14 data points, or 7 data points simplified.

This is the RPM, from COLD start.










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I think the exhaust VVTs from COLD start up to data point 700ish is doing its kinda EGR thingy for faster warm up. I read cars without EGR can use its VVT for this purpose.





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The first 109 data points only.





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Numeric view, data points 60 to 100 only, that is all I can image capture per 1 maximum page




This is my engine oil pressure data at my warm temperature, this is COLD start. Below is a 5Hz data or 1 second is worth 5 data points.
This is for you to relate oil pressure vs VVT shaky shaky.





Attached in ZIP, the original file from Xentry and the one I have made to Excel with German to English translation.
There is also another file of Xentry where the engine has idle at 3 minutes approx, I then record again the VVT.


You can also use this data to compare to an MB dealer techy data, ask them to log it this way when you have the VVT issue.

Okey, hope someday this can be useful to someone.