Hesitation/Stutter on over-boost/full acceleration

[noisybrother]

Hi all,

I hope you can help me, my car has had this problem for some time. I took it to Mini Nottingham (Sytner's) and they, ahem, 'diagnosed' deteriorating spark plugs which they duly replaced under warranty. Needless to say it didn't fix the problem. The car drove a bit better but the problem came back.

Symptoms:

Under full acceleration and at highish revs the engine stutters badly causing a dramatic loss of power, this is accompanied with loud metallic pinging noises for the duration of the stutter (detonation?) and smoke from the rear. I have not determined what colour as yet because it's more noticeable it the dark when illuminated by others' lights and of course all smoke looks similar in the sodium/halogen glare!

If you back off the revs it's fine and probably won't do it again until the next day, for example. It seems to happen just once a day and the first time I boot it; usually when in second or third gear. It won't happen if I am tootling along in fourth or fifth - it's almost as if I need to take it by surprise with a sudden & quick increase in revs.

In addition to this the car and probably unrelated as this is more recent, the car's coolant has turned a murky grey/black colour - no smell of fuel or combustion gases though.

Any ideas?

Hope someone can help!!

Paul

[mattblackbrough]

Hi Paul

I'm not going to be very helpful here other than to say I have a very similar sounding problem.

I get the 'metallic' sounding noises, when the rev's pick up quickly, every few days once during a trip and then it goes. I haven't noticed any smoke though. Mine doesn't sound quite as bad as yours though, it just holds off accelerating with a slight stutter and noise very briefly. Window down the noise is quite evident.

Its a bit of a pain that its so intermittent, it never does it when anyone else is in the car.

If you find anything out please let me know

Cheers

Matt

[clubbie]

Hi Paul,

I had what sounds like the same problem since december up until a few weeks back. As you describe, pottering around you wouldn't know anything was wrong, it's only when you push it. I experienced the same with it only really happening once a day too.

The garage changed the spark plugs & oil thinking this would solve the problem. As with yourself, it didn't. After further diagnostics it appeared the pressure was low in one of the cylinders. The garage dismantled the engine expecting to find a burnt exhaust valve. This wasn't the problem, it turned out to be a damaged piston head (a big chunk was missing). I have just got the car back and having to ease the engine in again after having all 4 heads and rings replaced. 5 months out of warranty, not happy!

[marque]

Hi

Sorry this may be a silly question but what model and spec is your car


Mark

[mattblackbrough]

Hi Mark

Mine is an 07 plate R56

Matt

[marque]

Quote: Originally Posted by mattblackbrough (original)

Hi Mark

Mine is an 07 plate R56

Matt

Sorry guy I have been away for a few days it sound the turbo is stalling and surging could be the air bypass valve wil have a look at my mate r56 JCW over the weekend and have a think but for a quick check I would deffenatly get the cylinders checked like clubbie says find someone with am enderscope pop out the plugs and have a quick look at the piston crowns rule it out it's easy to do will get back to you

Mark

[andrewdobie]

It does sound like an air pressure problem somewhere - like marque says it could be the ABV.

[onebigpaddy]

Quote: Originally Posted by noisybrother (original)

Hi all,

I hope you can help me, my car has had this problem for some time. I took it to Mini Nottingham (Sytner's) and they, ahem, 'diagnosed' deteriorating spark plugs which they duly replaced under warranty. Needless to say it didn't fix the problem. The car drove a bit better but the problem came back.

Symptoms:

Under full acceleration and at highish revs the engine stutters badly causing a dramatic loss of power, this is accompanied with loud metallic pinging noises for the duration of the stutter (detonation?) and smoke from the rear. I have not determined what colour as yet because it's more noticeable it the dark when illuminated by others' lights and of course all smoke looks similar in the sodium/halogen glare!

If you back off the revs it's fine and probably won't do it again until the next day, for example. It seems to happen just once a day and the first time I boot it; usually when in second or third gear. It won't happen if I am tootling along in fourth or fifth - it's almost as if I need to take it by surprise with a sudden & quick increase in revs.

In addition to this the car and probably unrelated as this is more recent, the car's coolant has turned a murky grey/black colour - no smell of fuel or combustion gases though.

Any ideas?

Hope someone can help!!

Paul

i could not have expleained it better, my 57 plates does the same,( not sure about the smoke tho) brought it in to mini while under warranty....yes u guessed it! nothing found...but it's just out of warranty now a few months...im not too good with engines, and dont trust mini at all! had mini's for 10 years now..for the love of the car..not the service.
i really hope you get it sorted..
andy

if anyone knows of a good mini garage in or near merseyside please let me know
happy motoring

[iain10]

Hey there guys,
had exactly the same problem as mentioned in the above, apart from mine was through out the rev range, and was producing black smoke from the exhaust when this occurred. This would possibly only happen once or twice weekly, then went to daily.
After having my local dealer look at it (whilst i was there observing), it came up with a fault called "Super knocking".
This has something to do with the engines timing, so they replaced the knock sensor and reset all the faults.

Touch wood, been a dream ever since, and maybe its just me, but even feels quicker. Now wondering if the timing had been variating for a while.

Hope this helps. Happy motoring

'09 Cooper S

[dvd-cooper-s]

Quote: Originally Posted by noisybrother (original)

Hi all,

I hope you can help me, my car has had this problem for some time. I took it to Mini Nottingham (Sytner's) and they, ahem, 'diagnosed' deteriorating spark plugs which they duly replaced under warranty. Needless to say it didn't fix the problem. The car drove a bit better but the problem came back.

Symptoms:

Under full acceleration and at highish revs the engine stutters badly causing a dramatic loss of power, this is accompanied with loud metallic pinging noises for the duration of the stutter (detonation?) and smoke from the rear. I have not determined what colour as yet because it's more noticeable it the dark when illuminated by others' lights and of course all smoke looks similar in the sodium/halogen glare!

If you back off the revs it's fine and probably won't do it again until the next day, for example. It seems to happen just once a day and the first time I boot it; usually when in second or third gear. It won't happen if I am tootling along in fourth or fifth - it's almost as if I need to take it by surprise with a sudden & quick increase in revs.

In addition to this the car and probably unrelated as this is more recent, the car's coolant has turned a murky grey/black colour - no smell of fuel or combustion gases though.

Any ideas?

Hope someone can help!!

Paul

I have the exact same problem on my r56, 2007 Mini Cooper S. The car has been returned to Douglas Park - Glasgow almost 4 times, and no faults have been found.

The car has only made this noice - metallic pinging - maybe twice or three times, and it is accompanied with the smoke. However I have also noticed a hestitation/stutter under accelaration and a degree of white smoke from the exhust at start up.

The hesitation is most notable on start up and it is quite worrying, especially under mild to heavy accelaration in third gear.

Hope to get to the bottom of this in the near future.

Many Thanks

David

[jamesmonty]

I have the same problem, I actually printed off some of this thread and left it with the dealer. They said the sensor needed replacing, has to be ordered from Germany apparantly.

Will be fixed under warranty (new engine needed due to death rattle, only silver lining is the warranty).

I love the car, but having owned performance honda's in the past, I really do miss not having to worry about the reliability of the engine.

[clubbie]

Quote: Originally Posted by jamesmonty (original)

I have the same problem, I actually printed off some of this thread and left it with the dealer. They said the sensor needed replacing, has to be ordered from Germany apparantly.

Will be fixed under warranty (new engine needed due to death rattle, only silver lining is the warranty).

I love the car, but having owned performance honda's in the past, I really do miss not having to worry about the reliability of the engine.

Any idea which sensor they are replacing? I'm still having this issue!

Thanks!

[d_wagonist]

im having the same issue.. when i WOT with gear 2 and 3, around 3000rpm, the stutter is so bad, its like im riding a horse! but if i were to do a gentle gradual hard acceleration, the rpm will climb smoothly.

had my mech checked the spark plugs and they r fine. but the ignition coil packs are kinda rusty and corroded.

tomorrow im bringing down to MINI for their mech to test drive..

btw its a 08 R56 S with 71000km.. and yes.. outta warranty..

[Clifford clubman]

Yep same here. It happens around once a week, and only if I'm really pushing it. I do hope it's nothing too bad. In all other respects the car is great. It seems to be a fairly intermittent problem. Foot down in 2nd or 3rd gear at around 3000 rpm.
08 cooper s clubman with 52000 miles on the clock

[stead34]

Could this be pinking because of carbon build up as the cooper s suffers with this....