Cylinder Mis-fires: dealer can't diagnose?
 

Hello All,

I've mentioned this problem in this thread: https://www.northamericanmotoring.co...d.php?t=107360

But, I thought I would try a wider audience. Has anyone here experienced the following: the DSC & Check-Engine light coming on simultaneously. Now, just the DSC light.

The lights come on, apparently, when you have a miss-fire in one of the cylinders: in this case cylinder #1.

The DSC module was replaced because that's what was thought to have caused the lights to come on. The lights still came on.

Then a burned plug and wire were found on cylinder #1 and those were replaced. Now only the DSC light is coming on and I'm still getting miss-fires in cylinder #1. Mini of Mountain View has had the car for over a week now and they don't seem to be able to tell me anything. Well, they have told me that the have contacted the " factory engineers" and would hear back from them in 24-48 hours. It's well beyond that time frame and no word. They gave me a 3 series BMW to drive in the interim, but it just ain't the same as my Mini.

Any thoughts would be greatly appreciated.

Regards,

nethack

I had a similar issue on my car. Never found a solution to it. Got a batch of bad gas which pinged the crap out of the engine and blew a piston. Seems to have gone away since then...

I had a problem with misfires to cylinder #4 for quite a while. It wouldn't happen every day, rather usually once or twice every tank. Dealship thought it was loose spark plugs, but only to one cylinder? Doubt it, plus I checked the torque frequently.

I spoke with Jan about it and he told me there have been quite a few problems with bad exhaust valve seats and that I should bring up this issue with the dealship. So this could be the problem on some cars.

Before I took Jan's advice, though, I also discussed the problem with Waylan of Way Motor Works. He said suggested that I ditch the iridium spark plugs for the JCW ones. The iridiums just have a tough time keeping the correct gap on our cars. I'm happy to say that I have not had a single misfire since switching to the JCW plugs, so I guess Waylan got it right.:thumbsup:

I also had this issue when I changed my plugs at about 95K. I checked the codes and it was showing a misfire on cylinder 2. I put on new plug wires and an MSD coil pack and have not had a problem since. I've read on NAM where the MSD is supposedly no better than the factory unit but it's been performing great for the last 30K. :thumbsup:

Thank you for this thread and your posts.
 

I had a flat spot at 3,000 on pulling hard through the gears. Took some of your ideas on the plugs and packs,
and now my MINI is back on form. It made sense to
replace wires, plugs... et all, as a system.
Thanks again,
Al.

minis have a bad problem with carbon deposits, im not saying that this is your issue just an idea. If you make frequesnt short trips i would bet on it. other things to look out for is a bad injector, or low compression on cyl 1.
just tossing ideas out

Oh great! The seven crappy miles (each way) I endure to get to work are killin' my engine. But this is the first time I've heard about the carbon deposit issue: any cure for that (except getting a new head and pistons and/or a longer commute)?

I'd try a bottle of Chevron Techron in each of the next couple of fill ups. IMO that stuff works & will help get rid of carbon build up. This is a cheap & easy thing to try.

How many miles on your MINI? If you've got a bunch the next move provided the Techron doesn't help would be plug wires if it was my car. Just my old fart old school way of trouble shooting. Your mileage may vary yada yada yada..... :wink:

My Mini has just had its second service/fluid/oil change. Just a tad over 26K miles on the odo. When I get it back from Mini of Mountain View I'll try the Techron thing just to keep it clean, so to speak. Thanks for the suggestion!

I put in a bottle of Techron at each oil change. 7,000 miles for each change for me. IMO it's best to do as a preventative measure. With your mileage I'd guess that your wires were good, but you won't know until the dealer tests them.

My car had what felt like a miss fire, split second drop in power, studder... i'm not exactly sure what you would call it... but it would drop out at 2800, 3200 and 4000 rpm. Always repeatable at that rpm. It was a really odd situation.

It never threw codes until finall i got it to missfire and throw a cyl 3 missfire code. Took it to the dealer and through bimcom (and black magic i guess) and they found out that the cyl 3 plug wire was done. replaced that and off I went none the wiser. The problem went away for about 3 months...

The all of a sudden it started to come back. Lukily at that time I was able ot throw the car on the dyno in front of jan and nick to get some people in the know to give their ideas.

It pretty much stumped all of us (well except jan I guess).

I went on a small rampage swapping parts:
plugs (50k miles on the odo... i've been through 5 sets of plugs... all the name brand upgraded plugs and oem through the course of those miles)
oem coil pack to new oem coil pack
oem wires to new oem wires.
belt
and oil change

None of those worked... although the car was running better for changing those items out. Jan suggested I take out the map sensor and hit it with a little carb cleaner. So on a whym i did it and the problem went away.

Who knows ft it will come back. It's annoying as heck... almost to the point of where if i couldnt' fix it i was going to sell the car.

Oh well gl with your issues.

your dealer has a BMW approved and proven very effective fuel system cleaner proceedure that they can do for you. I hear its kinda expensive but it you dont want to go that route, pick up a bottle of fuel injector cleaner in the BLACK BOTTLE at the dealership parts counter. its like mabe 10$ and i know this stuff works good, i have used it on my car many times.

Try colder plugs ?
 

No problems here, not using the OEM plugs - running colder one's as I have a 17% Alta SCP.

it's NOT the exhaust valves but the valve GUIDES:wink:
heads come into the machine shop from MINI all the time with bad ones causing the same scenario as above:)

Hey Jan, not to thread jack, but from your experience with the mini head do the valve guides leak commonly?

yes, the factory ones are cast and are known to go bad rather quickly

I knew I was going to get that one wrong...should have put a disclaimer. Thanks for the clarification Jan.:thumbsup:

no problem, I knew what you meant but I wanted to clarify for those watching:thumbsup:

Interesting! Especially since I just spoke with MoMV SA and they're pulling the head right now! Is this a known problem with ALL Mini heads? Since I have the JCW package I'm wondering if the JCW head is more or less prone to this problem. Also, I'm now wondering what kind of carbon build-up they're gonna see when they look at the head.

I'll keep y'all posted:thumbsup:

Regards,

nethack

The JCW head is identical in almost every way to the stock head. You'd have to look VERY hard to spot the differences side by side...

Given that, my answer would be that the JCW heads are probably no more or less likely to cause valve guide issues.

Besides misfires, what would be an indication that an engine has a bad exhaust valve guide?

Ok, here's the verdict: when the tech at MoMV removed the head, some play was found in some of the valves. Specifically in the exhaust valve on cylinder one. Enough play to burn the valve and the valve seat. The recommendation was to replace the head.

:thumbsup: The good news:
head will be replaced under warranty.

:eek2: The bad news:
the head is on back-order from the manufacturing facility in Germany.
Estimated time to complete the head replacement: THREE WEEKS! Minimum!

It's a bummer as I really HATE driving anything other than my Mini!

Looking forward to getting back to motoring (in three weeks or so)!

Regards,

nethack

Ding ding ding.... we have a winner:cry:


sorry to hear about your car... it sucks they are on back order for heads.... kinda tells you it's a problem... huh:roll:

Great thread! Is this a problem ( valve guides ) with the R56 motor as well?

Thanx,

Bill in P.G.

don't know yet but we will keep an eye on it:thumbsup: