This has been an occasional issue since I purchased the car in March. Just to recap I've had the entire timing chain components replaced, then ECU re-timed to sync mechanical and ECU timing. I've had an $800 dollar carbon cleaning, performance is great except for the strange occasional ping or pings mostly in third gear. If it were the HPFP I'd get a Cell. I will admit that since I went from the stock CAI to the AEM CAI, that the frequency and intensity is more pronounced with the AEM CAI but this issue still occurred even with the stock CAI. I use Shell V-Power 91 exclusively as my Mini runs well on it. Could it be the gas quality, perhaps but then why aren't others complaining of the same issues? My gut tells me that the cause is a lean event, meaning that at times it seems like I'm running just a bit on the lean side. The increase in air volume might be making things leaner since more air is entering into the engine because of the AEM CAI, it's all speculation at this point. It would be nice to finely solve this debacle! Dealer can't find anything wrong with it, so this is where I'm stuck! Gas mileage is 27 city and 38 highway. I've NEVER thrown an error code since I purchased this 2007 MCS.
Consider installing a ScanGauge.... You can monitor the AF ratio at the time the ping/knock occurs... Wouldn't think adding the AEM CAI would cause a lean condition as long as you don't have any connection leaks after the MAF.... The O2 sensor and the ECU make lean / rich adjustments...
Many years ago I owned a 87 Toyota GTS hatchback and I knew I was running lean so I measured the resistance of the O2 sensor and it showed that it was out of spec. When replaced I lost MPG but the engine ran much better. If I were to buy a Scan Gauge 2, could I use my iPhone 4S as the gauge with the Dash Command app? Is there a way to measure the resistance of the O2 sensors to determine if one or both are bad? Thanks
Nothing special about the Scangauge other than it can read AF ratio... I'm thinking AF is on the Dash Command as well.... Just need some indicator that correlates the pinging / knocking to AF... Would think you could test the O2 sensors in the cold state with an ohm meter... Don't know how you would test it running.... I'm thinking O2 sensors are either good or bad... Never heard of one that's just "weak" so to speak....
Could it be that during boost oil could be entering into the engine through the turbo inlet PCV piping?
It's possible... Or oil could be getting past the turbo oil seals if you have a lot of mileage on the turbo... Pull the hard plastic inlet pipe off the turbo and look for oil puddling at the cold side of the turbo...
Sorry to threadjack, but I have a quick unrelated question about the AEM CAI. Is there still room for a strut tower brace or is it in the way? I hope you can figure out the problem, that would drive me nuts if nobody could figure out what was causing the noise. Best of luck man.
I don't understand where the turbo seals are located, but I doubt my turbo seals could be that bad with only 50,000 miles, what's your opinion on the seals with low mileage? Wonder if I should pull my BSH OCC from eBay to use on turbo inlet My MCS has 50,000 miles and I noted absolutely no oil in the inlet cold side to turbo when installing my AEM CAI. Turbine wheel looks new, really clean looking. I stuck my hand into the turbo inlet to check for turbine wheel play and there's no play whatsoever! I strongly believe that my turbo is in really excellent condition. Is it likely that I'm pulling in oil via my turbo PCV inlet which is causing oil to be pulled into the engine causing the pings? If this is the case shouldn't there be oil on or near the turbo inlet?
Well... The turbo PCV inlet should be carrying some oil vapors from the valve cover... So you should see some oil residue on the cold suction side of the turbo... That would be normal... Can't respond to 50,000 miles on the turbo... Lots of things can affect the turbo bearing life and seals.... The turbo oil feed line can begin to coke up if the hard line is exposed to severe heat (MINI has recognized this as an issue and made two attempts at shielding this line with two different cover designs) Has the oil been changed on a regular basis and with a good full synthetic... Your turbo could very well be fine.... The turbo seals are located in the center iron housing where the oil lines and water cooling lines attach....
I do see oil dripping out of both PCV hoses when disconnected, but none within the turbo housing. I've been using Royal Purple 5W-30 at intervals of 5000 miles with 1000 miles to go before another oil change.