I have a curious situation happening as of late while driving my 2007 N14 Cooper S.



Today will be the third time this has happened.


About 5 Min. into a joy ride it happened. It was about 84 degrees outside with humidity around 75% or so. My fuel level indicator is showing 3 candy corns left and 90ish miles to empty.


I'm driving just outside of town on a 55mph highway. I slow down to turn right. I'm probably driving 30mph. It's a slightly aggressive turn. I down shift to 3rd gear. Apply full throttle. Then it happens.


It's happened 2 other times. Always when full throttle. In 3rd or 4th gear. Twice in a straight, this time just when coming out of a turn. I do not recall my fuel level the other 2 times. Today being the third event in roughly 2 months.


Once I press the accelerator pedal to full throttle, there is a series of Clicks from the rear. I'd say there are about 4 clicks. Very quick in succession. Like a relay noise. Or a pump. As the clicking happens I notice grey / black smoke in my rear view mirror. As I see the smoke, the car hesitates ever so slightly. As though there is a miss-fire or the engine is being starved of fuel. This all happens in roughly 5 seconds. Then all is back to normal. Quick, yet very concerning.


Some may notice I have posted one other time about these events. I believe I was going in the wrong direction that time. I thought maybe PCV related. But after today and hearing the clicks and with my lower fuel level, I'm leaning toward a relay or pump of sorts.


The bad thing about this, is there are never any codes. no warning lights. So I have absolutely nothing to go off of. If it continues, I'll keep updating this thread.


Any and all thoughts or similar experiences are appreciated.

 

Giving us the year/engine would be helpful.

 

See Sig. Everything you need to know

 

Thanks, can't see it on the phone.

 

Ah, I see. I dislike that phone app very much. I will edit the original post, but for your quick reference, 2007 N14

 

Did you see this? https://www.northamericanmotoring.co...d.php?t=139907

It sounds partly like it's the same issue.

 

I had not found that one. Thank you. It definitely sounds like the same problem. "Superknock" seems to be my situation. But there doesn't seems to be a definitive fix for said knock. I had the valves and cylinders cleaned (cylinders via chemicals) last year. Also has new plugs. So from what is left (assuming plugs are still good and intake is relatively clean) its either Vacuum leak or a HPFP issue. I'll do some more digging on this superknock issue and keep this updated.

 

Well after having time to further think about this over the weekend I decided to order another step colder spark plugs. Not sure if the tune is partly causing this Superknock to happen or not, but going another step colder should help keep the combustion temps down and help keep it from happening again. Plus I have the Wagner Competition FMIC coming my way. Should be here Wednesday. Hopefully between those 2 I won't have the problem again. If it does, then I'll try a seafoam treatment. I had the valves cleaned last year, but I guess it sould carb up quicker running a tune, not sure. For those who care, I'll keep this thread updated periodically.

 

Shot in the dark here, but you could be experiencing a momentary fuel starvation. Under similar conditions (low [~1/8-1/4] fuel level in the tank, hard right-hand turn, heavy application of throttle coming out of the turn), I have an '89 Firebird Formula that stumbles and sputters. Never does it with more fuel in the tank, and I've always attributed it to momentary fuel starvation when the fuel sloshes away from the fuel line leading from the fuel tank to the engine...

 

Has this only happened with it tuned? Have you talked to your tuner about it?

Have you tried removing the tune and attempting to recreate it?

What are your afrs? Are you too rich?

Sent from my Nexus using NAMotoring

 

I thought that a possibility as well at first, but the other 2 times this happened was driving straight with no turning. I did go full throttle those times as well, how ever it was in 3rd and 4th gears and not driving too fast, so I would not have been moving the fuel too much.

 

So far, yes only with the Tune. I am having a new tune wrote right now. I have a catless down-pipe installed and without the tune the car wants to enter limp move, which in turn would most likely keep this event from happening in this case. :-/ And I have not monitored the A/f ratios either. I will check those out before and after the new Tune.

 

A catless downpipe shouldn't put you into limp mode should only give you a CEL for emissions and drive the same.

 

Immediately after installing the catless DP with p0420 code and full throttle, the car would enter reduced power mode. But only if it was full throttle. All connections were fine, no exhaust leaks. Once the tune was uploaded and the P0420 code kept at bay, I have never entered reduced power mode since. So at least in my case, yes the downpipe does put my into a reduced state of power. I have heard of others doing the same as well. But on the other side of the coin I've also heard people having no problems at all.

 

Yeah, that stands to reason; missed that in the initial post...

I'd start considering the HPFP as a problem source; as an '07, there's a very good possibility that it's going bad -- even if it had previously been replaced.

 

Well, it happened again. Last night, as I was getting on the highway I was behind someone attempting to merge with traffic driving only 45mph (seriously, that's just dangerous). I was in 6th gear. As soon as there was space, I went WOT. I didn't down shift, the person was going slow enough, down shifting was not going to be needed. About 1 second after I hit the gas the same thing happened. Stutter. Noise. And smoke? (it was dark out so I can only assume there was smoke)

Things that were different this time. My fuel tank was about 80%. So I can rule out low fuel. Driving in a straight line (as opposed to turning last time). I was driving down hill. It was night time. All others were morning or afternoon. I would say it was around 80 degrees last night 75% humidity or so.

Since the last sutter, I have installed a larger FMIC, colder spark plugs, and uploaded a new tune. So I think I can rule out plugs and tune at this point.

I think I'm going to attempt a seafoam treatment in the next week or so, and see if that helps. I had my intake valves cleaned last year, but perhaps running this tune they get fairly dirty quicker? I may crack open my intake just to take a peak at the valves and check their status.

Not really sure what to do, but make check marks on things that I've changed or inspected. I'll update the post with my findings.

 

I've been having the same problem with my 2010 R56 S. It's happened to me at least 4 times that I can remember in the past couple months. The last time was yesterday. The first 2 times was when I was pulling onto the freeway on curved entrance ramps. I didn't see the smoke myself, but I had a buddy following me one of the times and he told me it belched out some black smoke. I had the car on a dyno about a month ago and it started sputtering and belched some smoke when doing a pull. Every time it happens, it happens once and then I try to recreate it, but I can't make it happen again. It's happened with a lot of fuel in the tank and very little fuel in the tank. My MINI has 39k miles on it now, plugs were changed in January. I had the timing chain tensioner issue and it was fixed by the dealer, but have a feeling it is happening again. I think some of the symptoms are appearing again. I'm really hoping to figure out what the problem is, I certainly don't want to blow my motor.

 

Well I took the my intake off over the weekend and looked at the intake valves. They're dirty. But not overly so. So I'm not sure if thats helping the issue happen or not, but I'll be doing the valve cleaning myself this time around. I'm unsure how well it was done in the first place. While the valves look like they've been done in the past, the amount on the valves seem thick enough it would be over a years worth of build up. I was unable to get any decent pictures of the valves with my phone, so I'll have to try to get a better shot when I try to clean them.

Updates to follow...

 

Ok, I finally got the tools required to do the Walnut shell blasting myself. I will probably get this done over Labor day weekend. But while I was searching for tools I did have the event happen again.

This time the fuel level was about 80%. Driving 50mph while driving up a slight hill on the eddge of town where there was a corn field to my left. I spotted a white tail dear running toward the road with it's tail up and with what appeared to be no intention of slowing down. I was in 5th gear and decided I would use my exhaust as a noise to alert the woodland creature. Of course it slipped my mind at the time that flooring it in 5th while driving up the hill at only 50mph had a very good chance of causing my issue. And sure enough with the pedal floored there was a sputte,r click click click, cough, and Smoke!

Idiot! Why did you do that?! You know thats the only time this happens!

Anywho, I have all the tools and equipment I need to blast the intake valves of my car so we will see if the concern is still there after I get that done. Then I plan on going to the dyno to get my numbers figured out and see what the A/F ratios look like and have Battle/DNA adjust from there.

It'll be interesting to see if the carbon build up is the fix or if the tune adjustment is the answer I'm looking for. And if neither of those fixes my issue, then where do I go from there? HPFP? PCV system issue? We shall see....

 

I've noticed mine doing that a few times when the outside temp is very high (above 90degrees F). It's usually when I'm in 6th gear and at low RPM. I usually attributed it from the car being in "overboost" mode and it's dumping too much boost into the engine and the timing is too far advanced to handle it. Which will equal a loud knocking sound and the power is sharply reduced. I've never noticed smoke from it, but I always get off the gas quickly when it happens.

 

I would also agree this happens during the 'overboost' function. I've read this happening to stock cars so I doubt the tune has anything to do with it, but I want to change one thing at a time to verify my thoughts. Hopefully in a couple weeks I'll have some answers to post on here.

 

Well I did the blasting. I also installed newer coils. I road tested in a specific route under specific conditions. It still happened. Albeit, it took a little more effort to get it to happen. But it happened none the less. This time I was driving about 45-50mph and in 6th gear up a slight hill, like last time. I tried in 5th gear and everything seemed ok. So I moved up to 6th to see. Fail.

The obvious solution so far is to keep my car in a lower gear. I never happens in lower gears. But I just can't shake the feeling this shouldn't be happening at all, no matter the load and gear numbers at the time.

I'll get to a dyno here soon. Send the info off to Battle and see if that is my remedy. If it isn't, then I'm afraid it might be my HPFP starting to take a dump.

 

When this happened to me I brought it to the dealer. They confirmed that the issue was the timing chain tensioner. They said that the superknock happens when the timing is off or with low quality gas. I havent had the problem again since the tensioner was replaced.

 

Hopefully this will be remedied with the tune adjustment. The fuel I have is 93 octane, so I can't imagine that being the issue, especially for how long this has been going on. And the tensioner was replaced 15k miles ago with the new design, so I pray thats not the issue. Hopefully I find out some day.

 

Which "updated" tensioner did they replace it with, the longer one ?