2nd Gen R56 Cooper S Most liked posts in thread: Engine Knock When Turning Off?

I only use Chevron 91 octane, I don't get as much pre-ignition as I did with Shell V-Power 91 octane. OMG when will California have access to 92-93 octane gas? This is the land of the Ferrari, Lamborghini and Porsche dealers along Pacific Coast Highway in Orange County! :mad2:

How does a camshaft position sensor work other than knowing the position of the intake camshaft? Oh and my intake camshaft is retarded half a tooth on the cam sprocket, my dealer showed me when they tried to install both cam locking tools the one that holds the intake cam the tool didn't lay flat enough to insert the single screw that locks both cam tools together. It was soo close to laying flat! I have been told it's not off enough to cause any sort of problem, thanks vanos I think...

I installed new motor mounts awhile ago, there's absolutely no movement even if you attempt to move it. The knock is easily identifiable as a dog or cat barking, I remember when I had my old 1980 Datsun 200SX FI 2.0 liter I4 (2 plugs per cylinder, before O2 sensors) when I turned the distributor to retard or advance it it would make the same noise.

Also it kinda sounds like your typical old classic V8 when turning it off it diesels, that knock sound but only once. Also I am no longer able to predict or reproduce the knock after turning the engine off. It doesn't sound serious because serious usually scares the crap out of you, kind of like the bucket of bolts timing chain rattle. I couldn't even record it because the normal sound of the engine drowned out the minor knock. I could pull the camshaft position senor tonight and maybe clean it, maybe there's oil in it's eye sensor.

It does, behind underneath the intake manifold I believe, I'll check my Bentley manual later tonight. I'm just going to replace both the knock and camshaft position sensor next month, maybe that will solve my pre-ignition which is still a knock.

My parking space is inclined to where the front of the Mini is on the top of the slope, but since I can't reproduce it the incline thing might not be a factor.

 

No dieseling, just the single knock associated with dieseling. It's a just a faint knock.

 

OMG, seriously thought that's my favorite sub movie period, only a few come near it. :lol::

Also to avoid creating another thread, could colder spark plugs (NGK ILKR8E6) colder than OEM heat range (NGK ILZKBR7A8G) lower cylinder temperatures and prevent detonation while driving in hot weather?

 

How is pinging/knocking/pre-ignition/detonation have anything to do with oil? Fuel igniting early could be cause be a faulty knock sensor, high cylinder pressures do to lean conditions. This is the first time I have ever heard of blaming oil for pre-ignition. My plugs are light gray which is considered normal, I have used Royal Purple and Mobil1 oils. Those oils?

My MCS runs great 95% percent of the time, idles smooth and good power.

 

I don't know if this could be related to my engine knock when turning off the engine or pinging/knocking while driving (occasionally, not often), but on this past Friday I pulled my plugs (ILZKBR7A-8G) to check the color and there gap since I hadn't looked at them in 13,000 miles since I installed them. The gap on all four plugs was .028, if I'm not mistaken aren't OEM plugs for a 2007+ MCS N14 engine supposed to be .032?

I adjusted the plug gaps to .032 for what I assume to be correct (from .028) early morning Friday, drove to work in hotter temperatures 81F no pings or knocks. Saturday night I experienced a light ping right after shifting into 3rd gear upon the first second of throttle application, it was 70F degrees and very cool last night. For awhile now I have noticed my MCS idling at 680-700 RPMS and idles smoothly.

I know for a fact that had I not increased the plug gap the ping probably would have never happened because now my thought is I must have a weak coil which we all know has trouble with shooting enough spark across a larger gap versus a smaller one. Sure it could have been bad gas, even though Chevron 91 octane (CA :frown2 which has proven itself to give me the the best performance and least amount of pre-ignition for any fuel used on my MCS since I bought it. Do to this low idling I have had my throttle adaptation reset along with unplugging my ECU for over a hour.

I have NEVER experienced pinging or knocking at these cool temperature (70F and cool) and the fact that all I did was increase the plug gaps a day before. My knocking/pinging has never happened in more than one cylinder, anyone know the ohms and resistance measurements on these coils when there new?

Is it possible that my pinging/knocking could be the result of a weak ignition coil and a 700 RPM idle? If so how can I determine which coil it could be? Ohms and resistance testing?

Thank you for your assistance!

 

From my Google search the oscilloscope are freaking expensive, will a digital voltmeter indicate weak or defective coil? If not would you or anyone recommend I take my coils in to be tested at some special shop?

Where in the Bentley Manual would I find out scope patterns, I'm still learning where everything is in that thick book. I haven't seen it in the Fuel Injection Section.

Thanks.