I have a 2007 Mini S which has not yet hit 50,000 miles. Recently I had a cold start problem which turned out to be carbon build-up on the valves. This time it was covered by the dealer. I am worried about the problem resurfacing. I have used high octane exclusively. My understaning is that this may be a congenital problem and that other Mini's have succumbed to the same flaw. I wondered what other folks are doing in regards to this problem. Thanks for any input. Nelson.
Many use the Seafoam treatment. There is a nice how to by OXYBLUECOOP ---Even MINI dealers use this product. http://www.motoringalliance.com/forums/cooper-clubman-engine-drivetrain/2002-how-seafoam-treatment-r55-r56.html
Get a bottle and make an adapter to the bottle with a hose that will fit on any direct vacuum off engine. Connect your new tool to the vacuum line. Run engine to operating temperature. Fill your bottle with any water. While engine is running slowly allow the water to be drawn into the engine. DO NOT LET ENGINE STALL. Do this for a couple of bottles of water. You will notice a black gooey substance coming out the exhaust. This is a good thing. After you have done a couple of bottles remove your tool and re connect the lines. Take your MINI on a brisk drive. Most all the carbon will be burned off. Any carbon that is left may burn off in a week of normal highway driving. You can do this application as often as you like to keep the carbon off the piston domes, combustion chambers valves and even clean the spark plugs. Chemical cleaner can not do as good a job as water! pm me for more explanation if you like.
what kind of gas are you using? try to use top tier gas... Top Tier Gasoline A friend of mine had the same issue...She was using regular unleaded gas from a grocery store.
I was surprised to see that BP (British Petroleum) was missing from the list. This is what I use, as I thought it was Top Tier???:confused5:
I asked a service tech about that... he said that they are inconsistent. Possibly the franchisees don't always follow "best practices" and BP doesn't control them as well???? not sure how acurate that was.
I've had problems with BP gas. It would stall my 1990 Integra. Acura service said it probably had too much ethanol. Switched to Shell and problem went away. Unfortunately, the problem of carbon build-up on valves wont be fixed with top-tier gas because the MINI uses direct injection. Gas is injected directly into the combustion chamber. So, the detergents in the gas never hit the backs of the intake vales. In an engine that doesn't use direct injection, the fuel is added to the air before the valves. This exposes the valves to the additives in the gas. The carbon build-up comes from crankcase fumes. Some people have added an Oil Catch Can to try and catch the oil fumes before they reach the engine. Anyone here done that? If so, which OCC, and how well has it worked for you?
How about an update "Dwight", I was following your progress up until we had the forum meltdown. I still haven't attached my 42 Draft Design OCC and really need to get it done. It seems the 2nd Generation S engine has a bi-polar (for the lack of a better description) PCV system. It seems that depending on WOT or cruising, the oil vapors might be drawn through the turbo / intercooler or when not under WOT, the fumes are drawn directly into the intake manifold. So it seems that most of the time I'm not running at WOT, the best OCC tap would be in the plumbing going directly to the intake manifold. Obviously, to catch the most oil fumes, two cans would be needed. But where to put them????? Any ideas anyone?:confused5:
I've heard about this from years back when the old gearheads would do this to clean the carbon buildup. I'm a little concerned about using the various "petroleum based" cleaners for a couple of reasons. My neighbors would lynch me if I fogged up the block with smoke until the treatment was complete. And lastly, some of the sensors could / might be damaged, and as I understand it, they are not cheap to replace. Is there any downside to using water, assuming I don't hydro-lock the engine? Would this work on the D/I engines to clean the valves?
It does not work as fast as non DI engines but the water vapor still get to the back of the valve and cleans it during overlap cycle of the cam. I have used this a few times with past friends that have had similar issues with their MINI. It is not likely you could hydro lock you Mini engine using this technique. lol The reason I said not to stall the engine is it takes a few more cranks to get it up and running again. You would die laughing if you saw how much water I use when doing a induction cleaning using this method. This is a simple solution with no downside. It will work for you or not either way you at least get clean spark plugs piston tops and combustion chamber bath.
Thanks Nitrominis, good info. So, short of using a borescope to check the results, how much water would one use during the treatment? Is the frequency to perform this after detecting some reduction of power or preventative maintenance at some regular oil change point?
I used to work for a co that tested petroleum tanks, pumps, lines etc for leaks and as part of their services they branched out to cleaning the sediments and sludge out of the bottom of the tanks (which over time builds up something fierce) BP, Amoco at the time, was one of their biggest customers and they refused to clean their tanks. Not sure if thats still the case under BP management but as a rule I steer clear of BP stations As a related topic. You stop by a gas station and the tanker is doing a fuel drop. Drive on by as the fuel drop is likely stirring up all the crap from the bottom of the tank. Some retailers are better than others on keeping their storage tanks clean and it can vary by regional retailer (BP in my town maybe cleaner than in your town)
Couple of things... A lot of Mini dealers are making this worse by overfilling at oil changes in a vain attempt to reduce the incidence of cold start clatter. Heck, they even overfilled my wife's base Clubman! Remember that with a DI engine, the gas goes directly into the combustion chamber, so it can't rinse the back of the valves like in port injection engines. This means gas quality has pretty much nothing to do with what builds up in the intake and on the backs of the valves. There are three things that make a Top Tier gas a Top Tier Gas! One is not less than 8% and not more than 10% ethanol. Another is higher than federally mandated detergent levels, and the last is paying to get to use the designation! Water for cleaning carbon is a very old technique that's been around for quite a while. I honestly don't know if it works any better or worst for the backs of intake valves on DI engines. Whatever you use to de-carbonize, do it more frequently than the rediculous oil change intervals suggested by Mini on the 2nd gen cars. I'm seeing more and more reports of cars getting screwed up by sludge and the like, and I attribute this to the ~20k mile change intervals for the oil that the car computer calculates. Change the oil at 10k and do a de-carbon at the same time, and you'll be good. No matter what you use (water or sea foam), I haven't seen any problems with the engine sensors and the like. Some say that you should change plugs after a sea foam treatment, but I haven't found this to be the case. I think it's just a persistant habit that crossed over to 4 stroke engines from the 2 stroke world. Matt
Have you ever had your oil analyzed to see what the water content is after doing a few water treatments? It would be interesting to know.
Did that on my R56 MCS as well. So, the higher oil level will put more oil vapor into the crankcase vent hose?
Surely they aren't overfilling to the point where the crank throw is hitting the oil level. This will create major problems very quickly. Dr O, what was the dealer's rationale for over filling. I thought the cold start was finally tied down to inconsistent cam chain length in manufacturing, as well as possibly delay in the time it takes to pressurize the chain tensioner? If the oil is maintained at the correct min and max levels on the dipstick, over filling has no effect other than to destroy the engine?
I think it's stupidity, plain and simple. They think that cold start issues can be mitigated by filling the oil more, so they do it to keep customer complaints down. Also they may rightly guess that many don't even check oil levels with the long change interval. But whatever. My wife's car was over the top of the indicator on the dipstick! Who knows how much gas mileage they're wasting to windage. I am just guessing that they are throwing more into vapor, but based on what a lot are seeing in the oil catch cans and intakes, I'm guessing that they are dumping more oil into the PCV system due to oil overfilling. It's just dumb all around. They should reprogram the systems to call for an oil change every year, or 15k miles, not more.... But they won't.... Oh well. Matt
That's strange, I have a 2009 JCW, and mine say's to change the oil at 13,000 miles or 1 year. Maybe they listened to you?:rolleyes5:
The interval on the OBC varies with how the car is driven. I don't know all the factors that are taken into account, but I've heard that length of trip, number of starts, and average speed are some of them. Mine indicates 19,000 miles to the next service.