engine running problem with 2005 Cooper S JCW
Discussion
I have a problem with my MINI that I hope someone here can help me with. I have already asked other forums (but on-one there can help me) as well as taking the car to the local MINI dealer on 3 separate occasion (no fault codes and they haven’t a clue…) so I’m hoping someone here might have experienced something similar.
I have the 2005 Cooper S with the JCW kit. When I accelerate, between ca. 2,800 – 3,200 RPM the engine splutters and feels very tight and, obviously, it has reduced power. It feels like the engine has a flat spot and then doesn’t get enough air or petrol, or the sparkplugs aren’t working correctly. It happens:
• between ca. 2,800 – 3,200 RPM;
• in any gear;
• under light or full throttle;
• the car is serviced at the MINI dealer, at the correct service intervals. (therefore, I assume the problem is more fundamental then requiring new fluids, filters, sparkplugs… etc, etc).
• there are no fault codes in the ECU;
• the problem is less pronounced when the engine is cold – it seems to be worse in hot weather.
• about 18 months ago, the engine made a big jolt (I thought something really bad had happened) and the Engine Check Light came on. It went to the dealer and had a new Lumber sensor fitted. This seemed to fix the problem but after a couple of weeks the problem came back;
• fuel consumption is no worse than normal for an old Cooper S (ca. 10l/100km in town).
I can’t really give more information/details about the fault. In general the engine runs OK, although I do sometimes think the engine doesn’t produce full power – it doesn’t feels particularly fast for a small 210BHP car. Acceleration off the traffic lights is never good (it gets bogged down on the clutch quite easily). I hardly use the car (drive ca. 4,000km/year) and tend to use 95 RON fuel.
Can anyone shed some light on what the fault might be?
I have the 2005 Cooper S with the JCW kit. When I accelerate, between ca. 2,800 – 3,200 RPM the engine splutters and feels very tight and, obviously, it has reduced power. It feels like the engine has a flat spot and then doesn’t get enough air or petrol, or the sparkplugs aren’t working correctly. It happens:
• between ca. 2,800 – 3,200 RPM;
• in any gear;
• under light or full throttle;
• the car is serviced at the MINI dealer, at the correct service intervals. (therefore, I assume the problem is more fundamental then requiring new fluids, filters, sparkplugs… etc, etc).
• there are no fault codes in the ECU;
• the problem is less pronounced when the engine is cold – it seems to be worse in hot weather.
• about 18 months ago, the engine made a big jolt (I thought something really bad had happened) and the Engine Check Light came on. It went to the dealer and had a new Lumber sensor fitted. This seemed to fix the problem but after a couple of weeks the problem came back;
• fuel consumption is no worse than normal for an old Cooper S (ca. 10l/100km in town).
I can’t really give more information/details about the fault. In general the engine runs OK, although I do sometimes think the engine doesn’t produce full power – it doesn’t feels particularly fast for a small 210BHP car. Acceleration off the traffic lights is never good (it gets bogged down on the clutch quite easily). I hardly use the car (drive ca. 4,000km/year) and tend to use 95 RON fuel.
Can anyone shed some light on what the fault might be?
I can't help but would be interested in any answers. My 55 plate MCS with JCW pack often has misfire/flat spots under acceleration (slight, med or heavy throttle) around the 3k rpm mark when hot.
Again dealers show no fault codes so nothing is wrong - shame theres no normal mechanics about nowadays!
My thoughts are potentially a coil pack breaking down?
Again dealers show no fault codes so nothing is wrong - shame theres no normal mechanics about nowadays!
My thoughts are potentially a coil pack breaking down?
a new coil pack or spark leads was my thought too but they seem to cost a lot of money (or my translation was wrong and I was talking about the wrong part....) so therefore I am wanting to get other people’s opinions first. A rolling road test might well be in order. Thanks for the suggestion.
I remember seeing a similar issue with a JCW on TotalMini a while ago (it's down (again!) so I can't provide a link). The cause of it, I think, was the bypass valve causing a flat spot at that rpm. I need to have a look into what this 'bypass valve' is and what it actually does.
Coil pack/plugs/leads is always a good first thing to try however. I can't imagine it's a difficult job to do, looking at it: disconnect multi plug at back & remove the 4 bolts attaching it to the top engine cover? I can have a look at my Bentley manual when I get back home.
Sorry that's not a huge help!
Coil pack/plugs/leads is always a good first thing to try however. I can't imagine it's a difficult job to do, looking at it: disconnect multi plug at back & remove the 4 bolts attaching it to the top engine cover? I can have a look at my Bentley manual when I get back home.
Sorry that's not a huge help!
Coil pack and leads were suggested because these are not service items, so although I have had the car serviced on the button, this problem still persists. It surprises/disappoints me that the service technicians don't seem to have the experience to be able to propose a solution, and this is the main MINI service centre in Munich run by BMW themselves....
If you could provide more information about the by-pass value, I would be very appreciative.
If you could provide more information about the by-pass value, I would be very appreciative.
I recall a bypass valve issue with my wife's Cooper. I was about 6 or 7 years ago so my memory may not be correct.
When the temp got down to 3C or below in the morning, it would stall all the time until it had gone about a mile.
It was absolutely lethal as, to pull away, it would need about 4000rpm and a slipped clutch.
BMW dealer had it overnight in -4c - I drove over to show them what happened and they still said nothing was wrong - pillo**s.
I did NOT pay their diagnostic fee.
Tony at MiniMotorsport (Shoreham, West Sussex) diagnosed it as the bypass valve (I think) and cleaned it out.
He said it was making the car think it didn't need richening for a cold start.
It may help bit hopefully is not misleading.
Never had the problem again though and may be down to most journeys being no more than about 5 miles.
When the temp got down to 3C or below in the morning, it would stall all the time until it had gone about a mile.
It was absolutely lethal as, to pull away, it would need about 4000rpm and a slipped clutch.
BMW dealer had it overnight in -4c - I drove over to show them what happened and they still said nothing was wrong - pillo**s.
I did NOT pay their diagnostic fee.
Tony at MiniMotorsport (Shoreham, West Sussex) diagnosed it as the bypass valve (I think) and cleaned it out.
He said it was making the car think it didn't need richening for a cold start.
It may help bit hopefully is not misleading.
Never had the problem again though and may be down to most journeys being no more than about 5 miles.
Had a similar problem with mine (2006 R53 JCW) last year - flat spots and hesitation under acceleration, no fault codes being shown.
After several dealer visits, the problem was found to be caused by a combination of a faulty boost bypass valve, which was replaced, and a loose hose to the supercharger.
After several dealer visits, the problem was found to be caused by a combination of a faulty boost bypass valve, which was replaced, and a loose hose to the supercharger.
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