The clatter could definitely be from collapsed lash adjusters. (The youtube vids sounded like collapsed tappets in pushrod cars). I dunno about the 'beating from the top' for coking, though.

The seals and guides are pretty isolated from the beating the valve shoe/tip takes. Usually the HLA or the valve's shoe would show the beating, if it's bad enough. Worse beating than that and you'll get other urgent and interesting problems some time before carbon buildup becomes noticeable...

Mini must know what's up by now.

 

Are the engines with carbon build up using more oil?

 

I remember occasionally adjusting the gaps on those old pushrod engines, when I think of it was always adjusting something. What's the other worse interesting problems that might pop up? Do you think this could be related to the cold start and computer system?

 

I'm definitely in favor of barraging Big MINI in the UK with emails regarding this problem. We need to let them know that the natives are getting restless on this side of the pond. I agree that they're probably aware of the problem, but I doubt that they will publicly recognize it unless they have to. i.e. A service bulletin needs to be posted with the dealerships with a fix or at the very least directing them to do the cleanout under warranty (rather than blaming it on "bad gas"....that still burns me).

HHH

Does anybody have an email address that can be posted?

 

Engines now are at such fine tolerances that small things trip them up pretty good, if some bit is off. The coking issue sounds like it might be something as simple as an off batch of pressure control valves or EGR return filters that are introducing some crankcase oil mist to the intake. Don't know how much of that is controlled (ECU) now - they used to be passive. The drawing of the valve cover is interesting. There are baffles in the cover that look to be for removing oil from the crankcase air before venting to the intake. Can't remember seeing that before.

The clatter sure sound like its in the valve train. What's disturbing is how long it goes on the youtube vids. The HLAs might leak down (dunno why more so in cold temps) but they should pump up quickly with 0W and 5W oil. Should be a couple raps, then quiet. If it's the HLA, oil isn't getting there.

The "Michigan Tom's" writeup and comments sound plausible.

 

Good read Zotz! I bet just about evrything on the engine is ECU controlled. Some cases the clatter has been observed when the car has been restarted after being on for a very brief moment - example moving the car out of the garage. That would make me think the ECU gets tricked into switching settings.

I agree with HHH, MINI should not be encouraged to use the bad gas excuse for the carbon build up. I've read in several other threads that reflashing the ECU has been used to treat several engine issues, - I'm leaning toward the idea that the ECU program maybe the root of the problem. Any one familiar with the what the ECU controlls and how?

 

Our Mini is an 07, bought Dec 07, with 6800 miles, not much. After reading this thread and also having the new tailpipes fitted in Dec 08, we decided to try a bottle of Techron. After just 2 days, the dirt dropping from those 2 brand new tailpipes is GROSS! We're still on the new tank of gas with the techron in it. Would like to try the BG44K but can't find it anywhere. I plan on cleaning the tailpipes in the morning & doing the "floor it" bit to see just how much more comes out. UGH! Is this amount of tailpipe "dirt" normal? Mostly highway driving.

 

You can buy it here. Scroll all the way to the bottom. Also, I would highly recommend buying the funnel to make sure you don't get any on the paint (highly corrosive).


http://www.handa-accessories.com/accmaint01.html

 

Thanks for that info & also about needing the funnel. Techron has a nice long neck which makes it easy to pour in.

 

MINI seems to be obsessed with replacing my tailpipe tips (2 notices so far?), but they don't show any interest in the carbon build-up problem. Strange

HHH

 

I think there is a huge problem here, I to are having the same issues however my dealer has just sent my frustration to a new level. My car has been in the shop for cold weather issues twice in the last three weeks. Each time the excuse has been 15% alcohol in my gas. I find this a cheap cop-out. First of all I use top-tier premium gas, and secondly the don't manufacture a 15% blend. All gas in the states have a 10% alcohol ratio of gas to alcohol. They are keeping it one more day we shall see.

 

Yeah that doesn't compute. I have the cold start chatter problem and we have 100% gasoline here. Plus the weather is really not that cold. I use Chevron 93 octane which is a tier one.

 

My wife's 09 Clubman S had to have the fuel injectors replaced due to carbon build up. She has 3000 miles on the S and we use 93 oct fuel.

 

I'm curious too. I've always put in Chevron 93 octane knowing it's suppossed to be a tier one. I wonder if the gas companies are trying to pull a fast one! If everyone is using the recommended gas and the dealers are saying the gas is not as it should be, then what other conclusion would there be if everyone is telling the truth.

 

Actually, since Chevron is a "top tier" retailer, you can be sure that it's not "100% gasoline".

One of the requirements for "top tier" status is that all grades of their gasoline, at all of their retail locations, must contain at least 8% and no more than 10% ethanol.

 

But, what's the possibility that it's not what we're getting?

 

Well, there's a fairly easy way to check the ethanol content of your gasoline if you suspect it's higher than 10%. All it requires is a graduated beaker or flask and a few minutes.

Get a graduated container that holds something like 500 ml. Measure out 200 ml of distilled water in the container, then pour it into another container and set it aside. Then pour 200 ml of gasoline into the graduated container. Add the 200 ml of water that you previously set aside, and then stir/shake the container for a few minutes and let it settle.

What will happen is that the ethanol will separate from the gasoline and combine with the water. So when everything settles, you won't see 200ml of water and 200 ml of gasoline - you'll see more than 200 ml of water and less than 200 ml of gasoline.

Measure how much "extra" water you have now, and divide that amount by 200 ml. That will be the percentage of ethanol that was originally in the gasoline.

So if you measured 220 ml of water and 180 ml of gasoline when all's said and done, that would mean that the gasoline was originally 10% ethanol (20ml/200ml). If you measured 230 ml of water and 170 ml of gasoline, then the ethanol content was 15% (30 ml/200 ml).

 

Unless it's been reprieved since the inaugeration, I'm pretty sure all areas affected by hurricanes Katrina/Rita/Gustav (coastal TX, LA,MS,AL, FL) are still under a waiver. At least they're still advertising 100% gasoline on the pumps here.

 

I'm a little confused - the purpose of the waiver is to allow the manufacturers to use *more* ethanol, not less. So if a particular retailer is taking advantage of the waiver, they may be selling gas with 15% ethanol, but if they're not, they should still be adhering to the normal "Top Tier" requirements and using 8-10% ethanol. One of the advantages of ethanol is that it allows refineries to "stretch out" their available supplies of gasoline, so I would think that the Gulf states are the last places that would forego the use of ethanol entirely.

Are the pumps you're referring to explicitly marked as "no ethanol", or are they just saying that there's no *extra* ethanol above and beyond the normal amounts? (In other words, they're not taking advantage of the waiver to add extra ethanol)

 

So this waiver could be in force in Texas and we could be using 15% ethanol?

 

The latest waiver I could find on the EPA site that covers parts of Texas is here. This waiver allows gas with a higher Reid Vapor Pressure (RVP) than normal to be sold. (Adding ethanol is the usual method of raising RVP).

The waiver was signed into effect on September 17th, 2008, and expired on October 1st, 2008, so it's no longer in effect. Normal fuel supplies have been restored to most parts of Texas for some time, so I don't know why they'd still be using 15% ethanol.

 

They say "100% Gasoline". As I understand it, it's an EPA waiver. Areas north of the coastal regions have 10% Ethanol.

 

Which state are you in? I might be able to find out more on the EPA site. I have found some references where states are asking for waivers to eliminate the ethanol because they're claiming that the forced use of ethanol is driving up food prices, but so far, all of the waiver requests I've found have been denied by the EPA.

 

Mobile County...coastal Alabama. Few if any of the stations around here sell gasoline blended with ethanol...at least if they do they do not post it on the pumps. When you get up to Montgomery and points north, all of the pumps (that I've seen) have a "contains 10% Ethanol" sticker posted on the pump.

So...I don't know the specifics, just what I've been told and experienced here. I have a neighbor whose in the gasoline retailing business and I will see if I can get more details as soon as I see him.

 

hmm this thread really gets me thinking...

I have noticed that my exhaust tips get REALLY black and sooty after a few days after a wash... It seems moreso than any other car that i have seen or driven....

I drive it pretty hard usually so im hoping my engine stays clean.