rough idle on cold start up few seconds - MINI Cooper Forum
Go Back   MINI Cooper Forum > MINI Technical Forums > Maintenance & MINI Care


Maintenance & MINI Care
Find Sponsor products associated with this forum
Questions and advice on keeping your MINI in top shape, from engine oil to body wax

Mini2.com is the premier Mini Cooper Forum on the internet. Registered Users do not see the above ads.
Reply
Similar Threads
Thread Thread Starter Forum Replies Last Post
R56 Mini Cooper Erratic surging at idle from cold start Norfolk-Mini Second Generation Faults & Fixes 6 Mar 13th, 2014 03:12 PM
Mini One start from cold noise MartinAnderson Maintenance & MINI Care 0 Feb 24th, 2014 06:19 PM
mini cooper s cold start problem njsupplies General Discussion 5 Feb 14th, 2014 10:21 AM
R56 stall and cold idle gkrobertson Second Generation MINI Cooper S 2 Aug 11th, 2013 02:47 PM
rattle. revs up and down, cold start, backfire, jerking misterdarkness Second Generation Faults & Fixes 1 Oct 20th, 2012 12:02 AM

 
LinkBack Thread Tools Rate Thread
  #1 (permalink)  
Old May 13th, 2014, 04:56 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
rough idle on cold start up few seconds

I have an 03 R53 Cooper S JCW and every morning when i start up the car she idles a bit roughly as in the revs very slightly increase and decrease. The unsteady idle goes away after about 10 or 15 seconds after. My mechanic at BMW tells me it is because my car is decatted and the resonator removed so the oxygen sensor reads wrongly. Is this true? I can upload a video if anyone needs
Reply With Quote
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old May 13th, 2014, 05:03 PM
MINI2 Master
Offline
 
Join Date: Feb 2011
Location: South london
Posts: 1,190
Local Time: 01:01 PM
United Kingdom Male
Hi

This is possible but it could be other things
has your car been remapped at all or you running the standard mapping ?

Are you running any other mods ie intakes, pulleys ?
Reply With Quote
  #3 (permalink)  
Old May 13th, 2014, 05:14 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
Nope have the standard map, note i have the 200hp kit not the 210. Have a K&N cone air filter, otherwise everything stock. Car never used to do this when decatted, most recent change is the resonator delete but even then it still started up fine.

Quote: Originally Posted by marque (original)
Hi

This is possible but it could be other things
has your car been remapped at all or you running the standard mapping ?

Are you running any other mods ie intakes, pulleys ?

Reply With Quote
  #4 (permalink)  
Old May 13th, 2014, 05:42 PM
MINI2 Master
Offline
 
Join Date: Feb 2011
Location: South london
Posts: 1,190
Local Time: 01:01 PM
United Kingdom Male
Quote: Originally Posted by aupshon (original)
Nope have the standard map, note i have the 200hp kit not the 210. Have a K&N cone air filter, otherwise everything stock. Car never used to do this when decatted, most recent change is the resonator delete but even then it still started up fine.


Ok cool
well I don't know if you are aware of this but by removing the cat you are loosing power :-(, the mini need the cat in standard trim. Basically you are telling the ECM porkies and you will mess up your AF ratios which means you will kill your engine. The standard manifold and cat will handle 230 plus hp.

This is way you will find most of the guys who change manifold to janspeed, JC and OBX will splice the standard mini cat

If you want to run with out the cat you will need the car remapped by someone like 1320 but they will advise you most portably to run the cat
Reply With Quote
  #5 (permalink)  
Old May 13th, 2014, 05:51 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
Quote: Originally Posted by marque (original)
Ok cool
well I don't know if you are aware of this but by removing the cat you are loosing power :-(, the mini need the cat in standard trim. Basically you are telling the ECM porkies and you will mess up your AF ratios which means you will kill your engine. The standard manifold and cat will handle 230 plus hp.

This is way you will find most of the guys who change manifold to janspeed, JC and OBX will splice the standard mini cat

If you want to run with out the cat you will need the car remapped by someone like 1320 but they will advise you most portably to run the cat


Wow ok well that makes sense, the car doesn't quite perform anymore anyway. And im purchasing a GP next week which is also decatted....**** i guess ill have to recat then.

Thanks for the help most intriguing I shall certainly be changing my thoughts on decatting minis now.
Reply With Quote
  #6 (permalink)  
Old May 13th, 2014, 06:03 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
Oh sorry one more question, after doing some research on loss of power with decatting i notice people mainly do it for the sound, now i am a huge fan of the sound when i stamp on it so would a resonator delete have any effect on the peformance? Should i just get a janspeed manifold?

I am down in Cape Town South Africa so acquiring tuners with mini knowledge and ordering parts is quite hard.


Many thanks!
Reply With Quote
  #7 (permalink)  
Old May 13th, 2014, 06:09 PM
MINI2 Master
Offline
 
Join Date: Feb 2011
Location: South london
Posts: 1,190
Local Time: 01:01 PM
United Kingdom Male
Quote: Originally Posted by aupshon (original)
Wow ok well that makes sense, the car doesn't quite perform anymore anyway. And im purchasing a GP next week which is also decatted....**** i guess ill have to recat then.

Thanks for the help most intriguing I shall certainly be changing my thoughts on decatting minis now.

If your buying the GP find out if it's been mapped and who buy then you can call them and find out if it was mapped with or with out the cat.

Depending on how it's been decatted it may have something like a janspeed manifold with a decat pipe installed. Which is an easy fix to put the cat back in

'The Tom-Cat' For Janspeed Manifolds. MINI - Servicing - Repairs - Tuning - Parts - Spares
Reply With Quote
  #8 (permalink)  
Old May 13th, 2014, 06:19 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
As far as i know its stock apart from being decatted, how its been decatted though i dont know, i shall find out.

As for sound/power gains what is the best route? I read a forum on mini torque that ultimately says a manifold upgrade with/without a decat is useless for power gains unless properly tuned with a map. Naturally other users say they significantly noticed an increase in performance when upgrading manifold and decatting/sportscat also they claim dyno figures?

here is the forum


minitorque.com/forum/f24/decat-power-loss-how-much-40547


ok i see the tom cat on 1320's site, so cat is definitely the way to go, i shall definitely dyno the car once purchased and then go from there with modding


Once again thanks as you are much more clued up than me
Reply With Quote
  #9 (permalink)  
Old May 13th, 2014, 06:50 PM
MINI2 Master
Offline
 
Join Date: Feb 2011
Location: South london
Posts: 1,190
Local Time: 01:01 PM
United Kingdom Male
No problem I was there once

The big problem is with decatting with out it being remapped or set up properly is the damage to the engine not so much the power

Personally I went for an OBX manifold it's 4-2-1 which I find gave me more mid range power it's a good price and not bad quality. And made a cat for it out of my old standard manifold. Basically a tom cat a local exhaust shop can help you out there.
The other option is a janspeed with a tom cat. I looked at miltec but there were problems with the cats falling apart but it might have changed by now.
If you could get hold of a JCM manifold but there like rocking horse pooo they are good

You could by a standard exhaust from a breakers for £60 to £100 and cut the cat off to use


If you want parts I use rich at orranje can really recommend him

Orranje - New MINI Performance & Styling Products
Reply With Quote
  #10 (permalink)  
Old May 13th, 2014, 08:34 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
Ok i see, ive seen a lot of janspeed manifolds and they sound pretty nice and seem to have good reviews so i shall look it up there.

First let me just get it over and sound like an idiot, i have a basic concept of a cat and know it changes the toxic pollutants etc but now it is the bulge just after my headers right? it looks like kind of weaved and stuff. Is decatted that cut off? or just the bits knocked out that convert the toxins. I still have the cat (bulge thing basically) but the guy at BMW said its not fully decatted so with the bits knocked out will it still confuse the ECU?

Once i've understood that then i think i'll want to get a Janspeed manifold for the gp and keep the exhaust as it is. Will i need a tune with the new manifold? Another thing if i get parts from orranje do they ship to south africa because that seems to be the biggest problem here, the tuning community isnt big enough
Reply With Quote
  #11 (permalink)  
Old May 13th, 2014, 09:45 PM
MINI2 Master
Offline
 
Join Date: Feb 2011
Location: South london
Posts: 1,190
Local Time: 01:01 PM
United Kingdom Male
Hi ya

Yer cats funny old things when they decided to go away from leaded to unleaded they found that they were putting out some bad chemicals worse than leaded.
So they shoved a cat on there to take out the toxic chemicals and hydrocarbons.

You have a pre cat which is there for cold temps ie from -20 to 0 deg c for instance and then the main cat for the car during normal running. The big problem is the 02 sensors monitor the emissions and sends a signal yo the ECM telling it wether it need more fuel less full to be with in a determined threshold at low rpm, this is the simple version it's more in depth but you get the basic point

I have attached a picture from the head flange the first bulge is the pre cat the woven mesh part is the flexible joint and the next bit it looks like a silencer it the main cat


Hope this helps there is no such thing as a silly question
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	11
Size:	33.0 KB
ID:	174130  
Reply With Quote
  #12 (permalink)  
Old May 14th, 2014, 10:51 PM
MINI2 Newbie
Offline
 
Join Date: May 2014
Posts: 11
Local Time: 12:01 PM
Ok definitely decatted then, i have the woven mesh but other than that there are no bulges, i shall be checking out my gp next week to see how that exhaust is looking
Reply With Quote
Sponsored Links
Advertisement
 
Reply
Tags:



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
R56 Mini Cooper Erratic surging at idle from cold start Norfolk-Mini Second Generation Faults & Fixes 6 Mar 13th, 2014 03:12 PM
Mini One start from cold noise MartinAnderson Maintenance & MINI Care 0 Feb 24th, 2014 06:19 PM
mini cooper s cold start problem njsupplies General Discussion 5 Feb 14th, 2014 10:21 AM
R56 stall and cold idle gkrobertson Second Generation MINI Cooper S 2 Aug 11th, 2013 02:47 PM
rattle. revs up and down, cold start, backfire, jerking misterdarkness Second Generation Faults & Fixes 1 Oct 20th, 2012 12:02 AM

» Recent Threads
Lights on warning not working
Today 11:42 AM
by S2dicky
Last post by S2dicky
Today 11:42 AM
0 Replies, 13 Views
LED Side Lights
Oct 16th, 2014 10:34 PM
Last post by Matty Kerr
Today 11:33 AM
2 Replies, 356 Views
JCW intercooler intake grille.
Oct 19th, 2014 08:06 PM
Last post by The Nun
Today 08:31 AM
3 Replies, 272 Views
New iPhone update messed up blue tooth, anyone else?!
Yesterday 02:35 PM
Last post by BeccaRoberts04
Today 07:37 AM
3 Replies, 208 Views
Automatic transmission - settle a bet!
Oct 18th, 2014 06:05 PM
Last post by whaap
Yesterday 11:49 PM
8 Replies, 540 Views
2001 Cooper wheel nut key
Yesterday 05:05 PM
Last post by Angib
Yesterday 09:00 PM
1 Replies, 202 Views
A pillar exterior trim Mini Cooper D 2011
Yesterday 06:49 PM
Last post by daniel_couch
Yesterday 06:49 PM
0 Replies, 157 Views
Mini One r56 engine rattle
Yesterday 06:41 PM
Last post by In Reverse
Yesterday 06:41 PM
0 Replies, 302 Views
R56 Aux input volume???????
Yesterday 04:00 PM
Last post by peteski2014
Yesterday 04:00 PM
0 Replies, 162 Views
engine fan on more frequently
Oct 16th, 2014 01:46 PM
Last post by heathwebbo
Yesterday 03:31 PM
2 Replies, 387 Views
Rear wiper motor stem problem
Oct 18th, 2014 09:57 AM
Last post by ScreamMini
Yesterday 03:26 PM
1 Replies, 257 Views
UK Big Brake fitment, what to do?
Yesterday 01:44 PM
Last post by todd tce
Yesterday 01:44 PM
0 Replies, 170 Views
Ac compressor
Yesterday 12:40 PM
by ronny
Last post by ronny
Yesterday 12:40 PM
0 Replies, 170 Views
MINI Roadster Headed to Frankfurt Auto Show?
May 19th, 2009 02:32 PM
Last post by angel10
Yesterday 09:02 AM
3 Replies, 4,124 Views
Automatic, won't shift out of park
Jun 30th, 2014 07:51 PM
Last post by Jazelmarie
Yesterday 12:00 AM
2 Replies, 1,012 Views
2001 Bini Central Locking key fob pairing?
Oct 19th, 2014 11:03 AM
Last post by mab01uk
Oct 19th, 2014 10:44 PM
1 Replies, 272 Views
No spray on windshield wiper
Oct 19th, 2014 08:54 PM
by mom7x
Last post by mab01uk
Oct 19th, 2014 10:38 PM
1 Replies, 213 Views
Storage Compartment Pack
May 29th, 2008 03:51 PM
Last post by sirron
Oct 19th, 2014 10:19 PM
6 Replies, 6,872 Views
» Premium
» Auto Insurance
» Wheel & Tire Center

Powered by vBadvanced CMPS v3.2.1

All times are GMT. The time now is 12:01 PM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.3.2