So i bought my mini at about 56k miles. Shortly after buying it i began experiencing some detonation and sometimes even timing pull under load. I decided fist to go after plugs just to cover my bases. I put in the ngk's with the right part number, and problem persisted. Next i began accumulating everything i needed for the walnut blast as i was sure it needed it. I completed the walnut blast today. Before and after pics attatched. This definitely helped return some lost power and smoothness, However after completing the walnut blast i am still having some detonation as well as timing pull.... Especially up in 3rd and 4th gear. Any ideas what i should look for next? Pics are posted in first reply... I couldnt get them to work right on this post

Edit: thought maybe i should include more info: it doesnt seem to matter at what boost level the car is at when this happens i have seen it happen at 11 psi, 13psi, and 16 psi. Sometimes it will happen on light throttle, and sometimes on heavy throttle. I always use top tier 91 octane. This morning i pushed it a little on the way to work while the air was cool and motor wasnt so hot and didnt get any detonation or timing pull, so i will have to keep testing to see if maybe outside air temp or motor/air intake temp is playing a part. On another note..... It seemed like max psi this morning was a solid 13psi....which seems a little low....maybe just because its humid and not as hot this morning?

 

 

Bump, anyone? I would like to get this sorted and eventually do some more mods...

 

do you have any way to check codes and/or monitor obd sensors? intermittent issues dont always trigger the dummy light. cylinder misfires will throw the light after just a few times, you swapped the plugs but its not uncommon for the coils to fail also - i bought mine used @30k miles and it already had 3 coils swapped, within 10k miles i had to replace another one.
using torque app or dash command and a bluetooth adapter you can monitor a lot of whats going on pretty cheap. the other common issue with these years is the high pressure fuel pump - pressures can be monitored through one of those apps. Mini has issued an extended warranty on them 10yr/120k miles, I am not sure of what years any more but i ended up getting reimbursed for getting mine fixed out of pocket (2011)

 

Thank you for the reply randeez. I will hook up to it with the scanners i have available and see if i can get into datastream to monitor pressures,etc. any particular range is should be looking for? Also i pulled plugs to get the borescope into the cylinders.... And there seems to be (what appears to be) fresh oil pooled up on the pistons.... Gonna see what i can do (temporarily) to bypass the pcv system. If this eliminates the pooled oil i will probably go ahead and replace valve cover and install catch can

 

you should be able to find the fuel rail pressure at idle should be 800-1000psi, WOT should be 1800+psi

the car will still run ok with lower but it is a pretty good indication that its going out,


as far as the oil on the pistons cant help much, i have the newer n18 it hasnt given me much trouble in the pcv/coking of the valves

 

Thank you again for the replies. I think i will be installing a cc and rigging up some sort of system vent both sides to atmosphere at least for now, as well as i will be cleaning off the pustons as best i can with solvent and a small brush. If this takes care of my oil issue i will be replacing valve cover.....if not im afraid i may be looking at valve seals or something along those lines. If those items dont relieve the detonation concer then i will move on to hpfp and coils