Was on my way home from work shifted into third and give it some stick and the car suddenly cut power along with some audible detonation. I am mediately got out of the throttle and a car then proceeded to run fine. Subsequent cautious attempts at both part and full throttle did not cause any issues.

Any thoughts? I am still relatively new to the car and I just had it inspected at a mini dealership last weekend who pronounced it in perfect working order

 

Hi Pakisho,

It could be a lot of different things.

The common issues to look out for that could result in pinging/detonation, it could be one, some, or none of these. In my case it was carbon build up, but I was too late and now my pistons are damaged, and god knows what else. You often have to be pretty hard on it to break it but sometimes they just break. My only tip is to not push it hard (boost much) until you've worked out what it is, unfortunately that requires a lot of patience.

- Your not running the right fuel (too low octane)
- Your MAF is dirty
- Your intake valves are carboned up and need decoking
- Your PCV is faulty and a little oil is mixing with fuel
- Your injectors could be clogged
- Your fuel pump is faulty
- Your fuel filter is clogged
- Your intake temps are too high
- You have a vacuum leak

 

I threw a few gallons of 100 octane in it, who knows how long the car sat at the dealer, and who knows what grade gas they put in it anyway. Running fine for now, lets see how it goes.

 

Did it again yesterday, off to the dealer we go.

It seems like it only happens when it goes into overboost mode.

 

The waste gate in the turbo is normally closed by spring pressure, and is opened by vacuum as required by the DME. Maybe there is a mechanical problem, or a boost control problem with the waste gate, causing intermittent over boost problems, thus detonation. Dealer should be able to find the problem. Keep us posted!

 

Keep us updated. I've been fighting this same condition for about a year now.

 

Keep us updated, If it throws a code, post it up.

 

Update: Dealer said a "superknock" code came back and he thinks it is a bad tank of gas. Wants to either charge $265 for a fuel system clean out or add a $10 fuel additive and go through a few more tanks of gas.

Trouble is, I already did that! Ran fuel injector cleaner through it and the car is currently sitting with a blend of 91 AND 100 octane.

Round and round we go.

 

Yeah, "Been There Done That" comes to mind.

 

Yep.

"Just one tank of good gas wont fix it, you have to run a couple of tanks through it"

Official verdict.

Not willing to pull the head to check for carbon because "theres no justifiable reason for it"

 

High pressure fuel pump, but that usually shows as hard to start first thing. How about the other fuel pump? The dealer crying "bad gas" is a classic weak act.

 

No starting problems. I may have to go to a different dealership. Bad gas is total BS. Its got a blend that works out to at least 94 octane in there right now.

 

So, going to pick up the unaltered car and then run it over to a different dealer on Saturday. Advisor at dealership 2 sounded far more knowledgeable and seemed to actually care about getting the issue fixed.

Dealer 1 said that a detailed test was run, and the car basically told them it had bad gas, as opposed to needing a carbon cleaning.

Such nonsense.

Edit: They will give me a printout of the codes, though.

 

I've had a similar problem on my 2013 JCW.
Power cuts out momentarily and then comes back on. Vehicle is at the dealership for the 4th time for this problem.
They have replaced fuel pipes, intercooler, high pressure pump and flushed the fuel pipes. Problem still exists, quite often occurring when under hard acceleration in 5th or 6th gear from a low speed and then happens just below 90km/h (~56mph).

Rather frustrating.

 

Hi, I know the thread is little old, but I am having the same problem with you. Did you figure out what is wrong? Mine is happening when I put my foot totally down on 4th gear at around 60kph and happens at around 80kph for 2-3secs then disappears.

 

Did you get the printout ?

 

Eventually they came back with cylinder bore problems - entire engine replaced. That doesn't seem to have completely solved the problem, but it is far more intermittent now than it used to be.

I have been told that there was a software update that fixed this issue in Cooper S, but there hasn't been any update for JCWs.

 

I have changed the spark plugs and the dealer said they have installed a new software, now it does less than it used to like 1 second duration rather than 2-3secs at the same speed and gear. Any suggestions to remove the issue totally? Is there a way to check ignition coils or hpfp or fuel filter? If I put jcw intake kit and put a downpipe and tune it, will the problem get any better or opposite? thanks

 

Im still chasing the issue. The fuel pump went out and they replaced under warranty (though I doubt that was causing the detonation even before it went bad). I did get the car on the road with a tech and was able to replicate the condition. His eyes went REAL wide when it pinged. So they ran a bunch of tests and did the walnut blasting. Things were much better until last weekend when it was hot out, and the car detonated again repeatedly and badly.

Im going to take it back in next week and see what they want to do about it. Frustrating, but I love the car too much to get really ticked about it.

 

I have decided to not dig too deep into this issue as mine is not that bad. Gonna put a downpipe, intercooler and will tune the car, then will see if the problem gets better or worse.

 

You should investigate the source of the problem before throwing expensive upgrades.

Just my opinion. Is your car still under warranty?

 

It seems you have the old troublesome N 14 engine as far as I read this board for mostly 18 months..

I am glad I have the N 18. No problem at 17K with 92 octane here in WA.

 

Definitely wait to get this issue fixed before throwing dp and tune. What if motor goes south? They can blame the aftermarket parts for causing the engine trouble.

 

After the software update from the dealer and spark plug change, it got better and now after catless downpipe and jcw airfilter, the issue didnt happen till today. Will observe it and see if it happens again or not, and will put a oil catch can to improve the air fuel mixture's quality. In any case the dealer wont afford anything that will happen to the car. I am not going to spend more money for the parts running already well. Fingers crossed..

 

You should have fixed the original problem before doing mods. This is just a question of common sense.

Good luck.