Hi,
I have ran into an issue with my 2009 Mini S with 95,000 miles 6 spd. Looking for anyone who has had a similar issue. About a month ago filled up with gas, and within a couple of miles started hearing spark knock it is worse when I lug it in each gear below 2800 - 3000 rpm and on a medium acceleration. This is a constant clatter until I let off the accelerator. When the 1/2 engine CEL comes on the spark knock goes away. I checked the codes there were 2 one for hard engine knock and one for a small evap leak which it has had for a long time. I first suspected the fuel to be the problem, drained the tank, refilled with premium and added a fuel conditioner. This didn't fix the problem. Next because of the mileage put new spark plugs in. Same problem . Next changed the in-tank fuel filter. Same problem. I changed the evap control valve. This cleared the Evap code still getting the spark knock code. I have checked the chain and guides and they are in great shape I have less than 68mm on the tensioner check tool. I have checked the VANOS solenoid strainer it had no debris in the screen. The car still idles OK and there is no death rattle or clatter at start up. So I walnut blasted the intake. No change. I have ran a compression test and I get weird readings 90 PSI on cylinders 1,2 and 55 psi on cylinders 3,4. No water in the oil and no compression carryover in the coolant system. I put a timing chain cam tool on the cams and the crank to check if the timing had slipped. They are correct. Before I throw more money into this for a timing chain kit and maybe a VANOS solenoid. I would like to know if anyone else has gone down this road?

Thanks in advance.

 

Can you post exactly the P code that you pulled from the system? The compression readings are low. Typically, you'll see readings around the 150 psi (this does vary) mark and have each cylinder reading close to each other. I'm sure you are, but just make sure you're using a good tester and are doing the compression test correctly. This should help: How To Do A Compression Test on a MINI Cooper. Let me know what you find out and what those P codes were.

2009 Mini Cooper S Hatchback - Engine Tools - Page 2

 

I had similar issues that slowly progressed with my mini Cooper and eventually became undrivable. I never got the codes for It however if I unplugged The eccentric cam sensor then started the car it wouldn't misfire and die. So I replaced the eccentric cam sensor and it worked. I also had a vacuum leak on PCV tube that runs to the intake. Hopefully this helps.