Hey guys, i am new to this forum.
I am a DIY person, and my girl owns a 2010 Mini Cooper Hardtop.

Her car had probably 10k miles when i first met her. By the time it reached 15k miles or so, her car felt sluggish. So i poured some seafoam in the vacuum line. It made it feel better for about a week. So then i seafoam'ed it again. But that time it made the car stall, and hard to start back up.... And ever since then the engine made more noticeable shaking.

I thought it would go away after a while, but it didnt, and it stayed with us until now, which her Mini have over 34k miles.

Somewhere in between 20-30k miles, she paid the dealer to do the fuel system clean up crap that costs about $200-300. It made a difference for 1 week. By next week the car felt like crap again. So that was about a year ago.

Now this month, it has been BOTHERING ME alot with her Mini. This is her 1st brand new car, bought and financed with her hard earn money. Shes the type that want to keep the car FOREVER AND EVER.

So i figure if she want that to happen, we better do something with the carbon build up issue. Thats when i started looking on google about it, well apparently MOST people have this problem.

Walnut blasting is pretty much the only effective way to do it, other than tearing it INTO the engine to clean it 1 by 1.
Since i am not THAT knowledgeable with the internal stuff, tearing it in is not an option.
Dealer told me it costs $1500 for the walnut blasting, spark plugs and fuel service is recommended. Total up 1.5k

Now thats some STEEP stuff for something not CAUSED by the owner, but the way they developed the engine.


My question is, does anyone have ANY OTHER suggestion, that doesnt require tearing it into the engine, or bringing it to the stealership.
Because atm, we can not afford a 1.5k to dump.

 

Carbon treatment via walnut shell blasting should be about $450-600. Some independent mechanics can be even a shade cheaper. Sounds like they are trying to sell he more than she needs.

 

@yetti96
I have seen quotes for 1,100 for just the cleaning. A member of our club was getting a timing chain fixed and since they were already working on her car they gave her a break at 900.00....

 

You should look into private shops that have the Walnut Shell technology. We charge $349 for the job. I know that other MINI shops around the country have the equipment. Where are you located? Maybe I can make a suggestion.

 

THIS! Don't pay nearly $1,000 for this service. Seriously, this stuff should be regulated by the federal government. The differences in prices at various dealers is ridiculous.

 

My 07 n14 has 57k, for around 20k I have had the bsh catch can and boost tap/pcv block off, and I run marvel in the oil at changes, also 4oz. At every other fuel up. Dealer recently did replace timing chain and inspection, they called pre- fix and told me $785 for walnut blasting and it would be recommended. He called back and told me it wasn't needed. Didn't say she was spotless or anything, but I've had the car since 21,000miles and previous owner never stated a previous blasting. Maybe I'm lucky, but this is my claim to why I have not needed it

 

What the hell. Walnut blasting, as a "required" service? Is this for the turbo only, or the older supercharged S, and non-S too? Cars are just getting worse and worse, I need my old 76 Nova back! Its bad when you dont have confidence that the engine and all the electronic gizmos and whegogs will work in even 10 years!

 

No, this is only for the direct injection cars.

 

And it's not MINI specific, loads of cars are going to DI, more MPG and HP...more maintenance unfortunately.

 

I have hesitated to post this, not because I don't think it will work - I think there's a good chance it will - but because I've seen some of the reactions to it on other forums. I have done a lot of research on this and have used it myself on older cars of my own without a problem, but have not used it recently on newer cars, as I haven't needed to.

You might want to try cleaning the carbon out by misting water into the engine air intake. There is numerous anecdotal evidence that this works - just google for "clean carbon from engine with water", or a variation thereof, cleaning carbon is a known side benefit of water injection and water injection is safely used quite a bit, especially for turbo engines, and I offer the following links I found that I think are worth special attention:
-- the first is a patent application for a device that uses water to clean carbon buildup from the inside of an engine http://www.faqs.org/patents/app/20100115721. It's kind of hard to follow, but the patent application seems to indicate that this process has been tested quite a bit during the development of the application.
-- the 2nd is an article where someone misted water into the intake of a single cylinder engine that had carbon buildup, with before and after pictures, to test the hypothesis that water would clean up carbon buildup http://www.files.thinksitout.com/Alt...f%20engine.pdf
-- and the 3rd is an article about "water gas" http://en.wikipedia.org/wiki/Water_gas. This article, I believe, documents why water cleans up the carbon in an engine. Most people think that the water "steam cleans" the carbon out. But this article documents a well known chemical reaction where water (H2O) combines with red-hot carbon (C) to produce hydrogen (H2) and carbon monoxide (CO). Essentially, the carbon is turned into a gas.

If I'm right, and it is the "water gas" reaction that cleans the carbon, then the only thing I'm not sure about is whether the carbon buildup on the intake valves gets hot enough for the "water gas" reaction to take place. It also means that the engine should be fully warmed up before you start misting the water in.

Given the above, I don't think you have anything to lose, as long as you are careful and mist the water into the intake. Do NOT pour the water into the intake as you might see in some articles. Here's a link to a video showing someone doing the procedure on a VW TDI

 

Oh, thanks so much for the clarification!

 

I am located in Houston Tx.

So all Direct injection cars will have a carbon build up issue such as this?

There are tons of car nowadays that is DI, and i dont see Toyota / Subaru / Honda have a carbon build up problem.....?

 

http://www.bgprod.com/products/fuelair.html

folks, this works and is the ONLY one I know that does as a chem. treatment. We soaked old valves in several cleaners and this ATE it up!! Removed carbon build up like it was nothing from the git go. DO NOT GET IT ON YOUR PAINT.
Not available to public but most all service shops I believe. Last I checked you have to be repair facility although some are selling it on fleebay.

 

My suggestion is to look into some extra types of insurance. I’m not sure what’s in your area but where I live there is an extra protection “insurance type” specifically for car repairs.
I know my response doesn’t answer your questions but if you’re in a bind to get this car fixed I suggest CAR SHEILD; they will help pay for any car repairs.

 

Thought I'd chip in my two cents worth...

An ounce of prevention is worth a pound of cure.

No MINI experience but with a VW Gof TDi (turbocharged direct injection diesel engine) the word was the intake would clog up from soot and oil/water vapor from the crankcase forming a soot/soft coating on the intake manifold. Over time heat would turn this hard and the build up would continue. Everything would be fine until at some point more throttle was used but the engine failed to rev any higher.

Cleaning -- very expensive -- was the (temporary) cure.

I loathe having to have the engine even partially disassembled for any reason. And I really loathe having this done for the sums of money bandied about.

What I did was 1) Changed the oil every 5K miles; 2) Used low sulfur diesel; 3) Avoided driving the car like a big rig. I used more throttle and rev'd the engine up over 3K RPMs often. Even doing this the fuel mileage average over 150K miles was 40mpg. Put the car up for sale. But I decided to check the intake. While the inside walls were wet with sooty oily mess there was no build up. Even the backs of the intake valves were free of build up.

With a gasoline direct injection engine I do the same thing: 1) Change the oil every 5K miles. (How this helps is as oil accumulates miles from contamination -- which is normal -- this results in the formation of more oil vapor. This oil vapor is removed from the crankcase and is routed to the intake and then into the combustion chambers were it is burned. But it can result in, will result in, build up at least on the intake valves and inside the combustion chamber.) 2) Avoid driving the car around at real low revs. So many are concerned -- and rightly so -- with fuel mileage but the trade off is for a bit more fuel consumption the engine stays clean and no expensive engine intake/head cleaning is needed.; 3) Gasoline is low sulfur. But not all gasoline contain good detergents. If possible I'd use Chevron Supreme with Techron every once in a while. Or if Chevron gasoline is not available I'd buy a bottle of Techron at the autoparts store and use it according to directions every once in a while. I use it a tank or two before time to change the engine oil.

While with a direct injected engine there is no fuel spray aimed at the back of the intake valves. However, a direct injected engine is designed to have some combustion gases flow backwards through the intake port. This happens when the intake valves open towards the very end of the exhaust stroke. This is intentional designed to contaminate the incoming air to lower combustion temperature to reduce NOx. It does this. But it can result in deposits forming on the back of the intake valves. This in addition to any build up from crankcase oil vapor. Using Techron this doesn't burn but does in the heat of combustion turn into a vapor. As the combustion gas flows into the intake port past the open intake valves it carries Techron in vapor form. As this contacts the relatively cool intake valves it turns into a liquid and will remove deposits from the back of the valves. Of course it also removes deposits from the surfaces exposed to combustion/exhaust gases.

Yeah, I doubt very many would switch to using more RPMs. But regular oil changes and using Techron is not that hard to do -- some dealer service departments will add a fuel/engine deposit cleaner but probably not Techron. (At one dealer talking the service advisor. He told me the dealer parts department carried some fuel/engine deposit cleaner (can't recall the brand) which is used by the techs in customer cars. (I asked it *not* be used in mine.) But the SA told me at each tech's toolbox was a bottle of Techron. The techs could have had what the dealer parts department sold at an employee discount but each bought Techron paying retail from an auto parts store.)

 

Thx RockC...the info is most appreciated and I'm going to give it a try and monitor it as best I can.

 

At what level do you consider low RPM's?

 

It is quite common with diesel engine equipped cars fitted with manual transmissions the owner short shifts. Kind of like a big rig. These get up shifted at or just under 2K RPMs. Sure the torque a car with a diesel engine has is intoxicating. The saying is we buy HP but drive torque.

Can't say what is too low. But what I can say is with my diesel engine equipped VW Golf I "rev'd" the engine to close to if not up to 3K RPMs. At least for a gear or two from a stop. When cruising at a constant speed I avoided a gear that had the engine barely above a fast idle.

My 2018 MINI JCW (with a 6-speed manual) was my first gasoline engine with direct injection. I was well aware of all the bad press gasoline direct injection engines get. Some of it deserved maybe. But I vowed to avoid usage that I felt would or could contribute to engine issues arising from direct injection. So I spun the engine to higher RPMs. I didn't bang the engine off the rev limiter just the 1st couple of gears the RPMs went to around 3K. Certainly the JCW would have handled being treated/driven like a diesel given the engine's good torque numbers.

My 2020 M-B cargo van (7-speed automatic) was direct injected. My 2022 BMW (8-speed automatic) is direct injected. And so too my 2023 MINI Cooper S (7-speed Sport dual clutch automatic).

The van I left in its default driving mode and just drove with a bit of a lead foot. Not a lot of lead but to be clear I didn't drive the vehicle as if there was an egg between my foot and the gas pedal.

Both my BMW and my S I drive in Sport mode. One reason is it disables that awful auto stop/start. (The van didn't have this system.) The other reason is while the transmission is still in auto shift mode the engine is allowed to rev up a bit higher before the transmission up shifts.

Might mention both the BMW and the MINI are delivering 30mpg fuel mileage. And my usage doesn't involve lots of highway driving. Mostly just around town driving. Sure the bulk of my driving is on roads with a 45mph speed limit during which the real time fuel consumption numbers are quite impressive. But there are stop lights...

 

Thanks for this discussion. I am going to do walnut blasting on my R55 next weekend (110k miles) – will check it with a borescope but my guess is its built up pretty good.


Two questions:

- what about carbon buildup inside the cylinders themselves (not just the intake valve)? I have read it's possible to do a seafoam (or similar) soak by pouring directly into cylinder but I haven't seen consensus on how this should be done (all cylinders centered, or doing one at a time bottom dead center), and ensuring you don't hydrolock anything.

- what about running seafoam (or similar) through the vacuum just off the PCV valve? I've read and seen a lot of videos showing this, but then also seen a select minority very adamant about not doing this because they say not all the carbon will burn out the exhaust system and some crystalized hard pieces can damage the cylinder walls. Also curious how this affects turbo vs non-turbo cars (mine is a turbo). Maybe it's just an issue if you have a massive carbon buildup and try a cleaner through the intake first – Let's say instead you do a walnut blast and get most of 95% of the carbon out – is it then safe to seafoam through the PCV valve afterwards?

Curious about people's thoughts on this

 

Thanks, I'd be interested in informed answers to these questions as well.

 

Reluctant to post this but years (circa early 1970s) my auto tech buddies told me for combustion chamber carbon (deposit) build up the SOP (at the time) was to with the engine hot and running at a fast idle to put a vacuum hose into a jug of water and with one's fingers or pliers pinch the hose to let just a tiny bit of water get ingested.

The water would not burn but in the combustion chamber flash to steam and when it contacted the colder surfaces of the combustion chamber revert back to liquid and in doing so remove the deposits.

The trick was to limit the amount of water to avoid killing combustion.

In severe cases the amount of water allowed into the engine was increased until the engine died then it was left to sit for a while. I can't recall now if before the engine was started plugs were removed and the engine cranked to ensure no cylinder suffered hydraulic lock due to the amount of water that *might* be present in the cylinder.

In really severe cases it was not uncommon for the deposits to come away in "chunks" and a piece get caught by the exhaust valve. This piece would eventually get pounded to dust but until that happened the engine sounded horrible.

At some point maybe with the appearance of direct injected engines there are engine deposit removal systems. These work on the same principle but use a "special" chemical and the "professional" ones connect to shop air which is used to generate a fine mist which is aimed at the open intake of the engine running engine. I've never used one but I'm sure there are better instructions.

But here is a link to a less sophisticated (and less expensive) model:


The result is the engine deposits are removed.

My SOP is to when engine deposits are suspected to use either Chevron gasoline with Techron or absent availability of Chevron gasoline to use Techron out of a bottle.

None of my engines over the years has given any sign of any deposit build up. However, I know this has occurred because many times at the start of a long road trip I'd drive the first leg at freeway speed for 100 to 150 miles. I'd stop for gasoline and notice the engine was running better. Since on road trips I use the same brand of gasoline and even when covering the same route stop at the same gas station and even use the same pump it is the driving not the gas. And even on just ~50 mile drive with no need to buy gasoline the engine runs better after the drive. One such drive had the engine which failed CA smog test passing with flying colors when retested right after the drive.

And once when I switched from running Shell V-Power to Chevron Supreme one car engine perked up after not even one tank of Chevron gasoline. However my other car engine when subjected to the same change in gasoline did not react good or bad.

I would not put anything in the cylinders. If the engine ran "ok" I'd use Techron. If not I might in a severe case use something like the cleaning system I posted a link to above.

 

Thanks RockC. This makes sense, but I'm not experienced enough to know if this actually works. But I bet there is someone here who has some professional experience.

In the meantime I'll continue to use Techron just before I do each oil change, although I put it in the tank and don't pour it into the combustion system.

 

Thanks for the tips @RockC . I'll be honest I'm still inclined to do a piston soak (in the future just using the Techron as preventative maintenance will be great. I think even the BMW additive for this is just rebranded Techron).

I'm comfortable doing the piston soak though I'm curious as the method as I've read a couple.

1 - remove spark plugs
2 - cylinder position here? not sure if it matters if you end up cranking it anyway
3 - pour a little cleaner into empty chambers. Let soak a while (24 hours)
4 - crank bolt by hand
5 - let soak more
6 - remove excess cleaner with vacuum pump
7 - crank with starter to remove any final moisture
8 - reinstall everything


Now in step #4 here, I'm curious as to what the difference is doing this with spark plug off and with the plugs loosely threaded on for some compression, if your goal is to also get cleaner on the piston rings. Of course don't want to hydrolock anything

 

I'm not a fan of putting anything in the cylinders that can wash the oil from the cylinder walls and piston and rings.

Even with the plugs loose the threads present a labyrinth seal and that can lock up a cylinder.