I have a 2011 mini non S with 27k mileage. It's been running great since i picked it up off prev owner. Last week i dropped it off at a parking lot for the airport and picked it up last night to find out the check engine light was on and shaking pretty bad.

I brought it over from Hawaii to San Diego a couple weeks ago and wondering if the cold might have something to do with it.

Needless to say i took to to auto zone and had codes pulled which are attached. Would you say this is from bad spark plugs most likely? I ended up buying the plugs while i was there and will have them tomorrow.

Last oil change was at 17k i think and i plan on changing it soon.

Fuel injector cleaner to the gas tank a bad idea?

I used seafoam on my mustang years ago.

Anyone here use similar products every now and then they rely on?

 

Only 27K miles is really early for a set of plugs to die, and suddenly getting mis-fires on 3 out of 4 cylinders isn't likely due to the plugs or coils all going bad at the same time. I'd guess either a fuel problem or maybe something chewed on some wires. By all means pull the plugs and check them out but I don't think that's you're problem.

 

Thanks for the reply.

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Could a dirty maf sensor cause it?

I fill up my tank at gas station on base which I've done for years. Pretty cheap gas but never had an issue.

Wiring harness under the engine or under the cover connecting to the coils? Reading around, the wiring might be corroded?

I'll be pulling the cover off Tom evening.

 

On a Cooper I wouldn't jump to it not being bad plugs. Those things destroy spark plugs in under 50k miles.

But, a coil pack isn't unheard of that early either.

Pull the plugs and check the gap for starters.

 

So i ended up replacing the spark plugs today, the ones i pulled out looked pretty dark.

I used NGK iridium that were pre gaped for my mini according to auto zone.

I looked at the inside of the boots for the coils and they didnt look bad to me, didnt see any corrosion. I checked out the electrical connectors at the top and they looked fine as well.

car still shakes with check engine, cant pull codes as i dont have a reader on me.

i ended up throwing a can of seafoam in the oil crankcase and cleaned the MAF sensor as well.

Anything else i can check for on the coils? the brand i have are Bosch.

Not sure how to check the fuel injectors. Would clogged injectors throw these same misfire codes or would i see something specific to the injectors code wise?

Going to purchase another can of seafoam for my fuel tank tom when i fill back up just to see if it clears a possible injector(s) clog.

 

post some pics of the plugs.

Go back to Autozone and pull the codes again to see if there's anything new or different. Highly recommend you get an OBD2 to Bluetooth adapter and the Torque app for your phone. (lots of posts here about Torque or the equivalent app for iphone, do a search and you'll find it) so you can pull codes anytime.

 

OK so after running this car around after replacing the plugs, i had the check engine come back on and pointing to cyl 4 misfire.

I then replaced cyl 4 coil and the misfires stopped for about a day. (no constant rough idle anymore)

I checked the codes after seeing the check engine light come back on and saw the 1 and 3 were randomly misfiring. I drove around like this for about a week while waiting on a set of 3 new coils to arrive.

Before changing the other 3 i had the P0420 Cat efficiency bank 1 code pop and after replacing the coils, i still have it popping up after being cleared with my torque app and Bluetooth adapter.

Looked around online and saw that throwing in some fuel injector cleaner could possibly fix the issue.

Should i just go with replacing the O2 sensor for now? would this be the upper or lower sensor?

thanks for any help.

 

I don't have much to go on from your details, but my 2011 Cooper S with 144K miles does this (specifically including that particular set of P300 through P304 misfire codes) at first start on a cold morning with a bad HPFP. Not saying that it's your HPFP, but funky fuel pressure will definitely set you up for this.

My recommend for diag since you have the Torque app: first thing in the AM, turn the car on (but do NOT crank the engine), and see what Torque says your fuel rail pressure is. If it's anything less than 72.5 PSI (minimum spec for low pressure fuel pump), or even if it's right at the line, don't be surprised at first-start unhappiness. You'll get one shot at this -- it's critical that you do this test when the car is cold-cold-cold and the engine has not been started, as post-start (even if you shut the engine off) fuel pressure may bottom out at a different place (mine always does) until the next cold-cold-cold reading.

Also note that the car repressurizes the fuel line when you open a door or unlock the car (that's that quick-whir-and-stop noise you hear). It's always anticipating that you're going to take it to the track, er, I mean grocery store.

 

Thanks i will give that a try tom morning and see what it reads.

 

Good luck.

Some quick notes from some testing I've done while I HPFP-tinker:

- Continue to monitor the fuel pressure with the app through the first start of the day. In fact, ideally, graph it and take screen shots.

- During that first start, don't give the car any gas or otherwise attempt to keep it from stumbling/stalling out when you actually crank the engine for the first time. You want to see "how it behaves without your help."

Context for this:

- Despite replacing both my LPFP and in-tank fuel filter, after sitting overnight my fuel rail pressure routinely reads, pre-first-crank, at below 72.5PSI (I saw a 58 yesterday; that's the lowest I've seen since I began working on all this, and it's consistent with behavior before the replacements).

- Other than after a pretty long sit, my while-not-running PSI definitely tends to stay at 72.5 or above. This makes intuitive sense to me, as does the idea that if all the pieces are working correctly, at first crank it should fully pressurize the line to spec as a first order of business.

- When dealing with a properly-behaving HPFP -- even if line pressure is as low as that 58 due to whatever the Mini does/doesn't do when sitting unused overnight -- PSI immediately goes to the 600+ PSI range when I start my car. It doesn't hover around in a low range and then eventually spin up; you can see (on a graph) that it begins to rise almost immediately, and keeps rising in pretty much a linear fashion, fast, until it is up to where it is supposed to be. The only time I have ever seen it perceptibly "hang out" at LPFP pressures (with the engine running) has been when dealing with an HPFP that I know for a fact is being wonky.

Hope this helps, looking forward to seeing what you get.

 

I believe the OP said is was a 2011 non-S, so no HPFP on that model. OP, can you confirm, Cooper non-S, as in it does NOT have a turbo?

 

Ohhhhhhhh durr woops did not know that about the non-S my bad nevermind