i have a problem every once in a while my car at idleit will start running rough.. 99 % of the time it runs great its that small amout of time that it does not i bought the car used and the car did have work done to it i can tell if its a 15% or 17% pulley i have the alta cai and super sprint exhaust i installed a boost gauge and narrowed the problem down to a vacuum problem ( rough idle was the same before boost gauge was installed and has not changed) so i know it was not the boost gauge install. the gauge will read about 12 on vacuum at idle which is normal and every once in a while i will loss vacuum which the gauge goes to 0 and the car will rough idle. the car will not stale but will run rough for about 15 to 20 sec and then go back to normal. i checked the plugs and wires and they are fine. HELP ROUGH RIDER

 

I complained about a similar thing with my MINI and our local Mechanic told me to run an Injector cleaner. So I ran a bottle of Redline SI-1 through it and it seems to be a little better. Will keep running it to see if it gets better. Could be worth a shot.

 

ill try that it seems that when i run hess gas the problem is a little worse i have been running mobil and seems to be a little better the pump saws less then 10% enthenol wonder if this may contribute to the problem i will try the injector treatment and see if it works also wonder if with the work done on the i need to step up on the injectors

 

Am running 15% redux, exhaust and an intake - car idles rough once in a while; 5 seconds after stopping at a light.

Switched to Shell; no issues. I've also consistently noted ~ 1 mpg improvement so price is a wash.

 

+1

I can tell you that when I run something OTHER than Shell, I get this problem almost every time. I also have an '04 with about 30K on the clock.

I fill up at a Valero station and my car does the same thing. When my MCS was stock, it did it, when I changed out the CAI, it did it... it's gotta be the gas.

 

Hmmm - my car has 29K. Maybe it only affects CR/W cars?

 

where are all the engine gurus out there that work on these engines ??? i know you guys are out there.. we need help.....

 

I get that too sometimes...my guage usually reads 14 vac at idle, but when it runs a little rough it is at 10 vac. I blip the throttle and it goes back to smooth idle and 15 vac I dont see how it could be a vacuum leak if it is fixed by either better gas or a blip of the throttle, but I could be wrong.

 

could be fuel filter... Does eveyone have higher mileage... anybody change their fuel filter?

daniel

 

36k and no fuel filter change

 

I had an idle problem like that twice before. first time it was a loose intercooler boot. Second time I never figured it out because I did a lot to the car that day. New gas and injector cleaner. I cleaned my air filter and checked all my boost gauge lines, I also cleaned my throttle body with a squirt of the same injector cleaner. My dad (a mechanic) recomended.

 

I also have a similar problem. Usually a few seconds after I crank up the car, the RPMs will dip and fluctuate for ~3-4 seconds. Then it levels out again. I don't think it's anything serious, but I would like to fix it if I new what to fix.

hmm... the_red_car's CR/W theory is looking even more probable.

 

I'm CR/W and i get the same problems. its prett infrequent, and i usually just ride it out. i pretend like i have a big cam.

 

My MA offered me an injection cleaning package the last time I was by the dealership. They said they have been experiencing complaints/concerns with gummed up injectors.
I declined because I had just ordered the JCW 380s and will install this weekend.
MINI seems to be aware of an injector problem.

 

Mine is DS/W so that can't be it. But it is running better after the Redline treatment.

 

let me know if the problem goes away after the jcw injectors install i was considering doing this i am surprised the dr obnoxis has not replied to this problem or one of the other high tech mini mechanics

if this is an ongoing problem and MINI knows about it the should be doing something about does everyone think the way i do and fix the problem no just acknowlede it...

 

Could it have a cam in it? Cars with a cam will occasionally sputter and sound rough at idle. A quick jab of the throttle usually clears it up.

I'd swap out the fuel filter as well if you haven't already.

A boost gauge won't tell you much, the vacuum will fluxuate depending on the RPM of the engine, so it doesn't mean a whole lot that it's moving around while the car is idling rough.

 

like i said i really dont know (about the cam) i bought the car used about 4 months ago i bought from a mercedes dealership and the guy who owned it did some major work to the car and when i bought it only had 17k miles and is an 04 exhaust (super sprint$$$$$) ,bbk, coilovers pulley reduction so on

the only thing i can think is that maybe he tracked the car dealership told me he traded this car and another car for a AMG mechanic pt on the computer and it said that some computer work was done and then 3 months before trade it it was switched back to stock at the dealer he may have had the computer flashed and the taken off before trade it at his trade it it had about 2 months left on the warranty.. and like you said a tap on the gas pedal and it goes away.... how else could you tell if there was a cam??

 

I wouldn't worry about it. Sounds like an idle lope from a cam. Like I said, swap out the fuel filter (People say they're "Lifetime" but I pulled mine at 20k miles and it was BLACK). The fuel filter is cheap, only about 30 bucks and a few hours to do yourself, or pay a mechanic an hour labor.

 

thanks i'll try this and see what happens...

 

FYI: Iv'e been told that the JCW injectors will spray same as OEM's unless your ECU is flashed by the dealer with proper mapping program to make them work to full potential......