Constant P0301 code
 

2010 mini clubman non-s N12 engine compression test numbers were around 165psi for cylinder #1 and the others were within 10psi of each other... injectors were swapped and misfire did not follow. The VANOS installed in the vehicle are the new design and not clogged, I recently acquired the vehicle with this problem so I don't know it's past. The parts I replaced are ignition coils, spark plugs all mini original dealer parts. I swapped both cam sensors and only one VANOS solonoid with ones from a 2011 mini cooper that runs and drives without faults. I'm only getting P0301 with a generic scanner but with ISTA/D I'm getting cylinder 1 misfire and random cylinder misfire. I've tested VANOS and everything reaches its set points and passes test plans.... no leak down test performed..... if I disconnect any cam sensor or VANOS electrical connector the car hiccups and then runs normal, the engine no longer misfires as viewed from misfire status..... any ideas?

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This post was auto-generated based upon a question asked on our tech article page here: MINI Cooper R56 Camshaft Position Sensor Replacement (2007-2011) | Pelican Parts DIY Maintenance Article

10 PSI difference is too much, 5 is the max you want. If one cylinder is high, there may be an issue with the exhaust valve.

- Nick

Compression results engine warm - cylinder 1 - 167psi.....cylinder 2 - 175psi ... cylinder 3 - 167psi..... cylinder 4 - 170psi.... if it is a bad exhaust valve why when I unplug any of the cam sensors electrical connectors or VANOS electrical connectors the car hiccups and then runs misfire free? Of course it throws a CEL for the unplugged sensor connector but the vehicle drives misfire free.

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This post was auto-generated based upon a question asked on our tech article page here: MINI Cooper R56 Camshaft Position Sensor Replacement (2007-2011) | Pelican Parts DIY Maintenance Article

Compression is not good. You may have a base engine issue. Too much variation in results.

- Nick