Can anyone help diagnose my car problem: gen1 bmw mini cooper S

gjonesy

Sorry in advance for the wall of text Im on an ipad. 

Hi Guys, Ive noticed theres a few car enthusiasts on here and was wondering if anyone has some mini experience? Ive got a 52 plate MCS owned from new (now ~140k miles) that has started giving me a bit of grief since Ive brought it back on the road after a 2 year layup. 

Its passed MOT recently and generally runs fine, the problem is that on start up it idles fine for about 30-60 seconds then the idle gets really lumpy/rough. It saves itself from stalling and theres no power if driven while its doing this. It resolves itself after another 30-60 seconds or if I switch it off then back on again. 

I had this problem once before and called the RAC out (before the layup). The guy cleaned the throttle body and all was well. Obd code p1688 which points at MAF sensor. Ive cleaned the throttlebody today and the MAF sensor on the front by the intercooler. I couldnt release the allen bolt on the other MAF sensor so left that alone. The idle was still rough after this and it did the same when I started it 30mins later. Took it for a 50mile spin (twisty bits and dual carriageway) and it ran fine. I'm thinking of getting an obd reader/resetter (can anyone recommend one?) to see what happens when its doing this. To me it points to a problem with fuel/air but Im no mechanic and this thing is nothing like the minis of old which I used to mess around with in my youth. Any help/comments are greatly fully receieved.

Fretwired

This might help - read the whole thing:

http://www.mini2.com/forum/first-generation-faults-fixes/71424-cooper-s-rough-idle-possible-fix.html

gjonesy

Cheers @Fretwired I saw that on my searches too. There's also suggestions of tmap/map sensor and crank pulley being at fault. Just wondering if there was anyone with first hand experience. Thinking about calling lohen or 1320 tomorrow.

guitarcookie1

Crank sensor caused this on my 325.

Danny1969

Yes Crank sensor can go faulty \ intermittent with often varies with temperature, can cause all kinds of faults from not starting at all to running like a dog at certain RPM 

TTony

gjonesy said:

Sorry in advance for the wall of text Im on an ipad. 

I just edited it - on an iPad too.

It's not hard to use para breaks on an iPad .... But it is harder to read it if you don't!

Sambostar

I'd say it was a sensor of some sort if it was laid up for a while.  Might be air flow sensor. Oxygen sensor?

Your crank sensor is basically your modern day distributor apparently, so that will affect the timing and cause it to run rough.

Fuzzdog

Might be worth popping in to a local Mini dealer for a quickie session on their proper computer - generic OBD codes are useful, but there are usually a big pile of manufacturer specific codes floating around in the background which may nail the problem down a lot more precisely.  My old 328 (which showed one singular not very helpful code with a generic reader) spat out nearly a whole page of (admittedly much more useful!) faults when I connected it to a borrowed BMW system.  :-O

Saved me chasing my tail and going slowly nuts trying to track the problem down though - the actual fault which was bringing up the light was absolutely nothing to do with the code the generic OBD picked up, and was fixed with a screwdriver rather than a visit to the BMW wallet rape, I mean, spares department!

jd0272

 ....rather than a visit to the BMW wallet rape, I mean, spares department!

This is why I now drive a Toyota........ Even the dealer is spot on.

markslade07

I reckon 1320 or Lohen will probably be a bit more clued up then some of the local BMW dealers. give them a shout, sure they give you some good advice

mike_l

Sounds like a stepper motor (Idle air valve) which is part of the throttle body.

Although TDC(crank) sensors, cam sensors (if fitted), coil or blocked fuel filters can all give similar symptoms.

Try running a good fuel system cleaner through the system first, as this might just be a slightly blocked injector.

 

gjonesy

Thanks everyone for their comments. I'm reluctant to take it to a BMW mini dealer as I've had some pretty bad service from them in the past (not just the one either) so it'll be whatever I can do myself or taking it to an independent.

mike_l

Try tapping the throttle body with a small hammer when it does this. Should indicate if the problem is in there.

I'm not too familiar with this specific car, I'm guessing it's a "fly by wire" so no throttle cable, so it's possibly a throttle position switch.

gjonesy

Yep its a fly by wire, throttle body seems OK as I checked it over when I cleaned it and it opens/closes fine on startup. I'll bang some injector cleaner in the tank and see how it goes. 

It started fine this morning and only did the "rough idle thing" for 5 seconds - not sure if thats because the air is a bit damp so its setting itself different.

mike_l

Sounds more like a slight fueling issue, rather than anything more serious.

I've used Wynns, Fortron or Forte for cleaners, and found them all good.

 

guitarcookie1

My local independent garage has a comprehensive code reader, similar to the dealerships ones. Maybe yours does too; £20 or so to have it plugged in and diagnosed is going to save you a lot of head-scratching...

gjonesy

spoke to 1320, they reckon its the MAP sensor (the one I couldnt remove). It sounds like they know what theyre talking about (plenty of questions and happy to talk me through) and since its not far off a big service I'll probably take it down there for them to do the work. 

I promised myself that theres no way I'm ever going back to Sytner Nottingham or Stratstone Derby.

Emp_Fab

I miss the old days of emptying shit out of float bowls and cleaning the points with a nail file.  I remember statically setting the ignition timing on an old Mk1 Escort using nothing more than a bit of wire and a foglamp.  In those days there was often enough room in the engine bay to stand in the bugger next to the engine.  Nowadays you can't get a feeler gauge between the gearbox and the inner wing and you can't fix anything without a diagnostic computer.

Eeeee....  by 'eck....  them were t'days - when RAC man would actually FIX your car at side t'road instead of simply towing thee t'main dealer.

Can't fix bugger all at side t'road now.... unless it's just a flat tyre n'all.

Tha doesn't knaw wha ah'v gone all yorkshire lahk tho.

Appen.

gjonesy

Yep know what you're on about @Emp_Fab my first car was a 1964 hillman superminx engine bay as you describe. I'm sure you could smuggle refugees in there easily. Moved onto a mini city at the other end of the spectrum then. Tiny car massive laugh (when it worked)

gjonesy

@mike_l so half a bottle of redx (half price at tesco) and the problem appears to have gone. Will change the map sensor anyway and I've found a centre console storage that I'll fit this weekend too. The service at 1320 can wait until next month. Happy days

Rox

Swap it for a real Mini.  You know it makes sound financial sense.

However, you would need to find a Classic Mini owner dim enough to do the swap...