R56 Mini- Mystery CEL

The wife's R56 Cooper S has been cranky lately. It started misfiring real bad a few weeks ago and running on 3 cylinders. Pulled codes, saw several cylinders had misfire codes, so we assumed it was the ubiquitous carbon build-up. We took apart the intake, pulled the intake manifold, and cleaned it up. Put it all back together, and that didn't fix it. Cleared and pulled codes AGAIN, and it was just misfiring on Cyl. 2. Swapped that coil with another cylinder, and sure enough, the code followed the coil. Replaced the coil, and it started running well again.

Now we've got a persistent CEL. Pulling the codes with the "Carly" BMW app via bluetooth gives code 0037DE, which is described as "ENGINE VENTILATION, HEATING." Not helpful. I hoped I had just forgotten to plug something back in, but that doesn't seem to be the case. Car is otherwise running fine, but it's state inspection time and that CEL is preventing that from happening.

Anyone have any experience with this?

Have you had the recall (sorry...service campaign) done where they redo do timing chain tensioner, guides and other bits? Sounds like a classic case of that... Totally fixed my cars random misfire codes when it was done.

Well, replacing the coil fixed the misfire. I pulled the valve cover to check everything out, and nothing seemed amiss.

Ahhh read too fast. EGR valve maybe? Can't speak to that error code.

My lists say 0037 is the heater circuit on the 02 sensors. One says sensor #2.

iceracer wrote: My lists say 0037 is the heater circuit on the 02 sensors. One says sensor #2.

Huh, interesting. Thanks. What list is that? I think the BMW code is different than a P0037, though. It'll throw "P" codes when it has them, but supplements them with BMW codes when it can. This one isn't throwing a "P" code at all, just the lone BMW code.

Yeah, I referred to the P list. I thought all emission codes were the same.

But then there is BMW, at least it's not a VW.

Well, the plot thickens...

I went back over everything I had touched recently, and found a small connector on the intake piping that hadn't been seated properly. Fixed that, and the CEL went away. Victory, or so I thought.

At my urging, Mrs. Unevolved loaded it up getting onto the freeway, revving up to about 5k or so. Hiccuped at about 4k, threw a CEL, and went into limp mode. Dammit. Pulled the codes late last night, and it's misfiring all over the place, except on Cyl. 2, which has a brand new coil.

Can't figure this one out. Doesn't seem to be an HPFP, since we don't have any difficulty starting it up, and the 2010+ cars aren't as prone to that as the earlier ones were. I guess tonight I'll repeat the code-clearing and try and provoke it again, see if I can get a more clear picture of what's going on.

Pulled the codes last night, misfires galore. So I cleared the codes, and we went for a drive. It idles fine, and drives fine at low load, but under any sort of load it misfired like crazy. Bad enough that it threw a CEL and went into limp mode. I took it back home, and cleared the codes, then fired it back up. Ran great like nothing was wrong. Huh.

Started thinking, there's a chance it's bad gas. The car sat for a couple of months while we moved and renovated, and ran fine before. The symptoms seem to line up, so we went to the auto parts store and bought a bottle of HEET. Let it idle for a little bit, then took it for a drive. Still misfiring, but noticeably better. It would stumble at high load when provoked, but never bad enough to throw a light.

So in the absence of a better path, Mrs. Unevolved is going to keep driving it and try to burn through the questionable gas, and see if anything else happens. Sure would be nice if it was something that simple.

Personally I would put some more dry gas in it and some injector cleaner and fill it up. If it is missing that bad maybe it is detonating too. If it was really bad I would try to siphon it out first or run a line off the fuel rail to collect gas while it is idling.

I know people here say that ethanol cannot cause any problems in a modern vehicle but I see it all the time when they sit.

Sorry I have nothing to add. I love MINIs and have always wanted one but this kind of thing keeps me away. My friend has one and it's constantly throwing CELs and is in and out of the shop for weird misfires. Always something odd, never easy. I have a Miata instead. Very peaceful.

If pre-detonation is bad enough, the knock-sensor may be trying to adjust the timing so much that it's throwing a CEL. I agree with trying to get the current tank through asap and run a couple of tanks of premium through it. Good luck. These issues are usually a bitch to figure out.

Thanks guys. If nothing else, it's encouraging to know there's nothing obvious I'm overlooking.

pjbgravely wrote: Personally I would put some more dry gas in it and some injector cleaner and fill it up. If it is missing that bad maybe it is detonating too. If it was really bad I would try to siphon it out first or run a line off the fuel rail to collect gas while it is idling. I know people here say that ethanol cannot cause any problems in a modern vehicle but I see it all the time when they sit.

" dry gas" is alcohol. ethanol is alcohol. Why add more ?

In reply to iceracer: Good dry gas is isopropyl alcohol. It absorbs water while still retaining a burnable solution. A cheaper dry gas is menthol. It doesn't remove as much water but it is still burnable. Both have been sold as a water remover for gasoline for a long time.

I know that ethanol can suck up a lot of water but as far as I know it has never been sold as a gasoline water remover. I wonder why?

Update- a week later, and it seems to be doing better. We burned through the tank of gas and filled it up. She said it'll still misfire when provoked, so we're not out of the woods yet, but it's better than it used to be. I need to go back and regap the plugs.

Yeah this kinda crap was the reason I traded in the wife's '07 Turbo. Try Cleaning the MAF also. Mine wasn't throwing a code for the MAF but ended up being the MAF when it was misfiring.

As soon as I could get the SES light to stay off for more than a week I traded it in on our 2012 Mazda3, 60k miles and no issues at all with it. Had the MINI for just 20k miles and in that time the blower motor for the A/C burned out, the timing chain guide ate itself and almost destroyed the engine, the MAF went out, the car had severe carbon deposits. 2/10 would not buy again.

And don't forget the thermostat housing that splits after 50k....

pjbgravely wrote: In reply to iceracer: Good dry gas is isopropyl alcohol. It absorbs water while still retaining a burnable solution. A cheaper dry gas is menthol. It doesn't remove as much water but it is still burnable. Both have been sold as a water remover for gasoline for a long time. I know that ethanol can suck up a lot of water but as far as I know it has never been sold as a gasoline water remover. I wonder why?

Back before ethanol I used isopropyl. Since ethanol, never needed any. You hear a lot how ethanol absorbs water and is a problem

So it's still stumbling under load, around 3k or so. This is SO frustrating. I think I'm going to have to drain the tank and see what's in there, maybe that'll tell me something interesting. I kind of doubt it, though. Not sure where to go next. Fuel filter? Recheck plug gap? Would that be this critical on this sort of thing?

The one light at the end of the tunnel is this whole experience has soured Mrs. Unevolved to this car. She's not a fan of driving an unreliable car, and now she's decided she'd rather have a used Tacoma instead. I'm totally okay with that.

I had a vehicle that would stall from time to time. I finally ran the tank low and then threaded a copper line down into the tank. A lot of cars make this impossible, then I siphoned all the remaining gas out into a pan. You could see the layer of non gas at the bottom. I added a few bottles of dry gas, filled it up and never had a problem again.

I may have made a development today... Unplugged the MAP sensor, and the misfire went away. Power was way down, but it didn't misfire. So there's a problem with the sensor, or something else that's causing the ECU to underfuel for a given boost level. Misfire is still directly correlated to boost/load, so I've at least got a direction to be moving.

ihayes wrote: Have you had the recall (sorry...service campaign) done where they redo do timing chain tensioner, guides and other bits? Sounds like a classic case of that... Totally fixed my cars random misfire codes when it was done.

Is this for 'S' models only or are all R56's affected?

rustysteel wrote:

ihayes wrote: Have you had the recall (sorry...service campaign) done where they redo do timing chain tensioner, guides and other bits? Sounds like a classic case of that... Totally fixed my cars random misfire codes when it was done.

Is this for 'S' models only or are all R56's affected?

I'm not sure. I don't think it's affecting our car, we're pretty consistently running into problems related to boost levels, and the chain/sprocket looked fine when I had the VC off.

Replaced the MAP sensor yesterday. Didn't help. Dammit.