Well they kept my MINI overnight just to make sure everything was working. What they found after 3 trips and two instances of "bad gas" was that the high pressure side of the fuel pump. They replaced the fuel pump and the fuel pump line. Seems to be working fine.
What I learned is that "bad gas" generally does not create a check engine light/code and was told that running two tanks of top tier gas would clean the so called gunk out of the fuel system. The bad gas excuse is just what it is an "excuse" . If your car seems to miss-fire or stutter every so often and you don't get a check engine light then it could be bad gas, but if the check engine light comes on then it is more than likely to be a problem that needs attention.

 

Thanks, msmith81. That tends to support my theory that the crankcase vent might at least be partially responsible for the problem. Although you can't really tell from the drawing, there must be some buffers or mixing vanes or something to disperse the vented material into the air flow.......or maybe not.

HHH

 

i've just got this problem too... i've had the occasional rough idle, and let the dealer know about it last week when i was there, they werent able to find it. now today the engine went poop while driving on the freeway to work and CEL was on too. came to a stop at a light n smoke pouring out of the exhaust... it stinks real bad.... reeeaaaalll baddd...



:edit:
oh... its a may/june build 07 cooper S w/ ~25k mi

 

I am (& I'm sure others are) very interested in hearing what the dealership says. Did you have it towed in?

HHH

 

Has anyone used Lucas fuel system cleaner? I've had good results and it's a non solvent type cleaner

 

No, but I use a MINI recommended product - "Fuel System Cleaner Plus".

 

I use a 50-50 mixture of Lucas fuel system cleaner and another brand, but I use it in a strictly preventative capacity, not to address any problems I'm having, so I can't judge how effective it is.

 

yah it was towed in, and i just got it back today.

apparently one of the fuel injectors was corroded and was stuck open, so it was constantly releasing fuel into the cylinder. when the SA called on Wed, he said that they had to removed the head to get access to the injectors and they saw some unburned fuel build up in the cylinder. they've replaced the faulty injector and had a mechanic take it for an extended test drive. compression testing came back ok by their word. hopefully it is, im going to drive it like mad just to make sure... im thinking that it might have damaged the piston seal, since there was bluish white smoke coming out of the exhaust. hopefully not...

 

I question the validity of the statement regarding additives. I'm not saying you're wrong... but it made me think.

I also have a diesel pickup which for some reason will manage to acquire soot in the motor oil, which I believe is a by-product of the combustion. Oil does get by the rings, down through valve seals, etc... and therefore I wonder if there was an additive present, if that would/could not cause issues.

I wish there was an "FDA" of sorts for oil and additives that would do independent research as to the effects, both short term and long term.

 

depending on how long that injector was faulty... I would say the possibility of the piston and cylinder wall not being damaged is quite low. That excess fuel will "wash" the cylinder walls of the necessary lubricant and the end result is fairly obvious. The rings will score the cyl walls and create more heat and damage the piston.

I believe someone can validate this with a simple scope check through the spark plug opening, but I am not positive on that.

 

Hmm....Very interesting thread. My 09 JCW has about 7500 miles on it. I drive it rather agressively, but I'm thinking I might add some Techron/whatever just to be safe. I do get the cold start rattle and it does scare me for what that might cause a few dozen thousand miles down the road...

 

Reviving this old thread with a new case. My friend bought a 2007 MCSa two months ago with 37K miles on it. Very clean car and running fine. Last Friday, he's headed out of town for Easter and when he turns off the cruise control while exiting the highway, the car just dies and refuses to restart. Gets it towed in to one of the Houston dealers (who will remain nameless until they do/don't resolve this.) Saturday morning, their service advisor calls him and says they think it's a fuel starvation issue and are still diagnosing it. They tell him the car was bought from them originally and has had all normal services and no big issues. Monday they call him back and now the story has changed. They now say that carbon buildup on the head is causing the fuel starvation issue ...and that the previous owner was warned by them of this impending problem because she admitted to using regular gas. I call BS. First off how did a "model owner" change to "careless owner" overnight, how did a fuel starvation issue become carbon buildup, and how does using regular gas (albeit premium is recommended) destroy an engine? Pretty much any car sold in the US will run on regular, it may be more efficient on premium, but I think it's a stretch to say that not using it will destroy your engine. Regular gas is not "bad" gas. I found this thread this morning and told my friend to tell the dealer to stop and call MINI National if they don't want to fix this under warranty. I usually take these things in stride, but all of the stories I hear about MINI dealers trying to deny warranty issues disgusts me. BMW, at least in my experience with a 330I and a M3, was no questions asked, if it broke during the warranty period, they fixed it. Sad to hear this crapola.

 

First, when they say "on the head," do they mean the carbon build-up is in the combustion chamber or prior to the intake valve.
The reason I ask is that in my case the build-up was prior to the intake valve. When the fuel is being injected directly into the combustion chamber, it's pretty hard to blame build-up in that area on bad gas.

HHH

 

Just posting to get this into my CP.

 

Story gets weirder (but with a happier ending.) Dealer calls my friend yesterday and says "something" internal came loose in the engine, they think perhaps a con-rod bolt, and basically trashed the motor. Piston skirts are broken, crankshaft is galled, and low or no compression in any of the cylinders. They say they have never seen anything like it before but it will definitely be a warranty item, they even gave him a MINI loaner even though he was not the original buyer of the car from them. I'll update when I hear a more exact cause. Just wondering , does MINI/BMW replace failed engines or rebuild them? I know Porsche replaces the entire short block engine assembly when they have problems rather than fix them at the dealer level.

 

The failed engine will be replaced with a new engine, or (more likely) a factory-rebuilt engine. The dealers aren't equipped in any sense (time, skill, equipment, or personnel) to do engine rebuilds on-site.

 

Hmmmm...the engine damage you describe sounds eerily similar to the reports we've seen of engine self-destruction due to cam chain failure in MINIs that have had degenerative experiences with the cold start death rattle.

I don't suppose there is any way of knowing if, or how many times, the original owner might have complained about it -- particularly since the seemingly mandated, standard MINI SA response is that the noise is "normal." I wonder if your friend ever had the rattle experience during his initial two months of ownership.

 

I'll post more details as I get them. I don't think my friend's car ever exhibited the coldstart rattle to him, I think he would have mentioned it to me when it happened if it had. I guess I haven't read up on all the coldstart threads either, I didn't realize there had been actual engine failures that may have been related. I was pretty surprised period to hear of a total engine failure. The dealer is telling him it's the first time they've ever seen anything like it too, although I've long ago learned not to believe everything a dealer tells me.

 

Sounds like a classic case of what "bad gas" can do to a MINI.

Just kidding.....It sounds like a whole different thing. I'm glad the dealership is taking positive action. Let us know how it works out.

HHH

 

Yep... there are threads here and there on NAM, MINI2 and a couple of other sites where the cold start rattle progressivly gets worse, till engine failure. Slipped/broken timing chains with totaled engines were the result. Many of those I'd read about were 07's with about 25-35k miles.

If too many engines detonate Mini >has< to come up with a fix. Jury's still out on the latest version of that fix.

Haven't heard anything new on carbon issue however. There was talk of a modified valve cover to deal with oil vapor, but no-one could verify it.

 

My friend got his car back Friday with a new long-block engine installed. Root cause for the failure was listed as "seized vacuum pump and exhaust cam sprocket bolt backed out." Could that factor in with the cold-start theories?

 

The sprocket bolt probably wasn't a factor. There's more than two bolts holding that on, so losing one shouldn't have allowed the sprocket to shift and change the tension.

More likely the bolt was poorly tightened at the factory, and it backed out until it struck something. Then it broke off and started circulating around the engine, damaging parts as it went.

BTW: MINI is now addressing the cold start rattle issue. Look for Mini Engine Service Bulletin SI M 11 02 07 issued March 2009, NHTSA #10024513. I can't find the actual document, but the basic details of the TSB are posted at the Mini Owner's Lounge under the topic "Repair Your Reputation..."

 

Two "seized vacuum pump" diagnoses in a month.

Things that make you go hummm....

 

Thanks for the headsup regarding the Service Bulletin. Not too handy at navigating the Lounge but I found the post just as you said. Mini USA Owners Lounge> Mini USA Owner Network> Message Boards> Suggestions to Mini > Product Development > Repair Your U.S. Reputation

 

Out of over 200,000 MINIs sold in the world in 2008? That's not much of a trend (0.001%), but two of the same thing does make you wonder.