I have a 09 justa, recently I have been noticing a really bad cold start idle. It hunts and surges for about 20 seconds. It bounces between 1100 and 800 RPMs. Theres no rattling. After the car runs for a while it hunts less. The car still hunts but only about 100 RPM after its warm. There is also a, I'll call it a hiccup, when I declutch. It comes down fine till about 1100 again and then drops off, the engine then catches it self around 500 and runs fine. I was reading and saw the thread about the carbon build up. I only have 15000 miles on it so I figured it couldnt be too bad. I seafoamed any way. It made things smoother buy still hunts like crazy on cold start. I was thinking it may be the spark plugs, factory says replace them every 50,000. Any suggestions before I go replacing everything? or take it in to the dealer?

 

It's not likely to be the carbon build-up issue; that's confined to the turbocharged engines. Seafoaming it probably didn't hurt anything, but won't solve this particular problem for you...

Seems to me I've recently read some other posts with folks having similar issues as you're experiencing, but I just can't seem to dredge up any threads dealing with rough cold-start idle on a "Justa" (only Cooper S)... Can't be a high-pressure fuel pump in your case either (again, confined to the turbocharged engines). Could be a bad oxygen sensor...?

Try searching for idle problems. Or hopefully someone else (whose memory is better than mine is today) can chime in with more/better details...?

Ultimately, you may just need to take it to the dealer; with an '09, you should still be under warranty.

 

If you have no lights, you can "x" out any sensor malfulnctions. Could be the Idle air control valve, either way take it to the dealer, get a loaner

 

Mine is not a manual transmission car, but I had a similar issue. Sometimes it shook pretty badly. My local Mini guys consulted with someone at Mini central and then simply turned the idle up a couple of clicks (however they do that, I think its done with software).

Mine idles smoothly and reliably at about 850 RPM now.

 

Eh. Good point...

Well, perhaps my memory was better than I thought...? I wanted to say there was a software update involved in the solution to this rough idling, but was reluctant to cloud the issue without being certain.

I think the bottom line, though, is you'll just need to take it to the dealer for warranty service...

 

Do you buy gas at the same gas station most of the time?

My 08 JustaCooper was doing this last winter & spring. Mine would stumble and "hunt" at idle for about 10 seconds, then smooth out & be fine after that. Very mystifying as there were no codes or other apparent problems.

I remembered having a similar problem with a Lexus I owned in the past. I tried switching gas stations for 4 or 5 tankfuls - and the problem went away. None of my other vehicles had ever had a problem with gas from that particular filling station - but the Lexus didn't like it, for whatever reason.

I tried buying gas for my MINI at a different place than normal, again for 4 or 5 full tanks - lo and behold, no more "hunting" and rough idle. It's been fine ever since.

It seems like a very simplistic fix, but it has worked for me in the past. Give it a try, nothing to lose!


ps - - I'm not suggesting there's anything wrong with the gas you put in your MINI - I'm sure it's fine - it's just that mine seems to have a preference for fuel from some places over others. Maybe yours is the same??- -

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Yes i buy gas at the same station every time (Until now). When i brought the car in they said just that. So i figured i would give it a shot. I got one of the gas treatments from BMW. I have to do some research but I am pretty sure that Hawaii has only one refinery. Either way I am going to run the new gas, clean my MAF, and let the dealership see it. I heard about a ECU software update so maybe I am missing that. Either way its on the dealership.

 

Well, that's certainly a good thought too, "33EJB." Despite what your dealer told you, "Inked469," MINI recommends that you use only Top Tier fuel suppliers. If you're using a "budget" fuel supplier, that may very well be the source of your problem...

 

This is true... but even fuel from a top-tier supplier can have the same effect. My Lexus did not like the 91 or ultra-94 gas from the Sunoco station I was patronizing at the time, and that's certainly a good top-tier fuel. So switching from one top-tier fuel to another can be beneficial in a case like this, too.

It's worth trying before spending the time (and $$) to have the dealer try to track down a problem (like I did with my Lexus) that might be solved by this simple fix. It also worked for my MINI.

No guarantees, just worth a shot... and an added bonus to going this route -- if the rough idle persists after switching fuel brands for 4 or 5 full tanks and you end up going to the dealer for service - - you already have a good answer to the "it's bad gas" response that seems to be common for many different issues from some MINI dealers... you will already have tried several tankfuls of different brands of fuels to no effect.

Like I said - it worked a couple of times for me, is easy to do, costs nothing, and gives you a leg up if the dealer tries the "bad gas" routine.


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Indeed. My dealership is very good at hunting down issues. I have about 200 miles before I need to fill up again. I am going to try the top tier gas for a few tanks. Another note. It has gotten worse now that I have added the BMW fuel additive. Now it hunts from 500 to 1500 rpms. I used to use lucas oil and I stopped adding that last tank. I wonder if the to additives are fighting each other.

Also the dealer can only take me so far with bad gas. Mini's computer should adjust for different octanes. If it persists I am going to hook it up to my scope and see how the coil packs and plugs are running. Perhaps I just had bad luck with them, if so its a simple fix.

 

Hawaii has two refineries, Tesoro and Chevron. They are both in Kapolei. Tesoro is the larger of the two.

Dave

 

So as I drove by my usual gas station I saw the Tesoro truck pull up. Def not top tier, theres a chevron down the street so I will give that a shot and let you guys know. Thanks for all the help and suggestions.

 

Tesoro, Chevron, or whatever, the gasoline is the same. I've worked on tank ships, moving petroleum products up and down the west coast, we would load at one companies refinery and discharge at another companies tank farm. It is just a commodity. Different companies have their own additive packages, but that is mostly marketing snake oil. If you want Chevron gas, fill up at Costco and add some Techron.

The whole "Top Tier" gas thing is just a marketing ploy, nothing more.

Dave

 

I agree the gasoline all comes from the same source, but my experience suggests that the additives do make some difference. I spend time in Texas (San Antonio and Waco), and have run my truck there on both the "el cheapo" Valero brand (which is now making headway even into the Pittsburgh region), as well as top-tier brands like Shell, Texaco, and Chevron. I've noted a definite difference in the way the vehicle runs; much more smoothly (no knocking/pinging) on the top-tier brands for the same grade of fuel...

Since the only difference, as you noted, is the additives, and I've done nothing else to the vehicle except change the fuel I put in it, I have to conclude that they are what are making the truck run more smoothly...

 

Dave,

Yes gas is the same every where, once it gets to the station though its different. All though I do feel that where you buy gas plays a factor different than detergent. I remember an article a few years ago during the gas price hike talking about when to fill up. They mentioned a few key points.

1 Fill up in the morning. You get more liquid content of gas.
2 Dont fill up while the truck is filling up the tanks. The transfer of gas stirs up sediments in the tank. Which are then transfered to your tank.

So it is impossible to chalk up any change to "quality" of gas alone. There are way to many factors in play. As for the top tier gas, I read through their testing procedure. Typical marketing yes. They dont mention where they get the gas, how they run the engines, how long they run them, etc. So my idea behind switching gas is that, the current gas station I use has no additives in the premium gas, if it does they are not listed. So I am going to switch to one that does. Secondly the one I use now is very busy. I see the tanker there every day. It could be that there is a lot of floating crap in their tanks. So switch gas stations has more to do than just the brand name.

 

Ok folks. Got the Justa back from the dealership. I was reading around and found that they are pretty much worthless unless there is a CEL. They did a cold start check on it. Tech noticed hesitation...... I am glad they acknowledged that something was going on all though it is not a hesitation. They are sticking by their top-tier fuel statement. Though this time is was not about additives in the fuel but overall ethanol content. Correct me if I am wrong but I was pretty sure that anything over 10% and was labeled so, did damage to your car you could win some money off that gas station. I am no lawyer though. I am curious now to try it. More so than before. So I am almost up on a new tank. I am going to hit up a "top-tier" place and see. Can't hurt.

 

It's a shame that there are so few real mechanics out there, someone who can diagnose a problem without relying only on an OBD2 scan and swapping parts.

If the computer doesn't see it, it's not a problem or it's the customer's fault, right?

Dave

 

All though I have noticed one thing. The car runs a lot better on their oil. I did my own aftermarket oil change. With the recommended oil. 5W-30 Castrol Synthetic, I think. After the car came back it runs a lot better from what I saw on the list of things they did. The dealer did not do a tune up. So it I can only link the difference to their oil.

 

Just to keep everyone in the loop. I have now been running Chevron (much to my wallets displeasure) for a couple of tanks. My mini runs a little better. Its smoother but the same issue is still there but a lot less noticeable. I figure that I notice the idling a lot more since I installed the NM torque arm insert a few months back.

 

Inked469,

What is the current status of your rough idling?

I have a 2011 Justa Cooper and have been having this issue since I took delivery of the car in January.

The car has been to the dealer, Yaletown Mini, 3 times and all they can is that is the fuel. On my car the gas door explicitly says 89 octane but the dealer is saying I am required to run 91 octane or higher. They have done tests on the fuel and say my ethanol content is too high. They want me to run 91 octane or higher for 2000 kilometers before they will look at my car. Since my last visit the idle has been getting worse everytime at startup. Prior to the dealer visit it was mainly noticeable when it was cold.

So if I have to run 91 octane or higher in this economical car where are my fuel savings?

 

You may find that your mileage will improve with premium gas and the savings from using lower octane gas is a wash.

I do think that blaming the gas for uneven idle is a crock. I drove a Cooper S identical to mine, except it had a tankful of regular, it idled just fine! It just didn't have the power that my car, fueled with premium, does.

Dave

 

I did see some differences with running two different brands of fuel. Very minor. I was trying to replicate my results by just adding techron to my fuel but I didnt keep the car long enough to see if anything changed. MINI's are by far the most sensitive to fuel I have ever run into. I now have a BMW and it runs just fine on the "crappy" fuel. I guess its all just preference. But I would run 91 octane regardless in the MINI, see if it makes a difference for you. Worst case your only out a few bucks and some downtime while the mini is worked on.

 

Yes, I will use the 91 octane for their recommended mileage just to appease them but from what I have seen so far I highly doubt it will make a difference. I am a car guy and my car guy friends all feel this is Mini Yaletown's way for me to go away for awhile.

 

My '09 Cooper does the same thing (though I'm not positive on the exact rpm range)... has from the beginning, essentially, and I have used Top-Tier 93 octane Shell gas for all 46k miles, so it's not bad gas.

I'll be at the dealer for a 'party' tomorrow, so I may ask about that. Maybe get an appointment sometime soon. It doesn't really seem to be a "problem" or affect reliability necessarily, but it shouldn't do it, of course.

 

I guess its all personel preference. I didnt know you could make a car so picky on gas.... the question is though where is the problem coming from? What would make the car run so different on different gas? My question is to anyone who has a car that is chipped or has the ECU reflashed are you seeing the same issues? I have heard a couple of people talk about the dealership uping the idle RPM's to around 800. Anyone else have this experience?