I have a 2012 Mini Cooper S and I'm getting check engine light with reduced power. Misfires that vibrate the seat. Changed spark plugs, no fix. After a trip to a friendly mechanic he recommends trying a seafoam treatment before a costly cleaning of the carbon buildup.
Here's where I'm lost.
The car has the newer style engine. There is no hose on the back left corner of the engine to introduce the seafoam into. Every video I've found on YouTube has a different style engine. The car has 54k miles on it. Am I the first one looking to do this?
Everywhere I look for a schematic I cannot find it. I'm trying really hard not to spend 500 here when I'm almost sure a few treatments and some spirited driving can burn this stuff out if there. Help from Anyone with any tips or even a few pictures would be great.

 

Any codes stored? Maybe a coil going bad? Lean condition due to failing HPFP?

 

Due to the number and type of codes he believes it to be a carbon buildup from it being a direct injection. Two cylinders went down. It's unusual that 2 coils go bad at the exact same time.

 

you would be the first I heard of this carbon problem in a N18 car. And from what I've seen of seafoams actual ability to clean a valve I would not waste your time.

I'd get a second opinion if I was you.

 

If it is actually carbon buildup causing your problem, one trick that I found to actually work is running your engine at higher-than-normal RPM on the highway. I first read about the method on some BMW thread, and have tried it with success on an N14 (older style engine) MINI. As the issue stems from oil bypass that collects the carbon and sticks it to your intake valves, running at high RPM will slowly but surely burn off the oil on the intake valves, releasing the carbon and burning it off. After a 45 minute trip at 3.5-4K RPM, the engine ran smoother at idle, and made significantly more power on boost than it did prior. For not having a vacuum line to run the sea foam, this is the best advice I can give.

 

This...

 

+1 Commonly referred to as 'An Italian Tune Up'. Back in the olden days before Moby **** was a minnow it was called 'take it out on the road and blow the cobs out of it'.


You gotta be kidding me! The language nanny doesn't like the common name for Richard? What a weenie.

 

So I commute everyday and drive quite enthusiastically. Generally above 80 mph, usually in the 90s. High rpms were a daily thing. Right now however the engine is on limp mode with the check engine light on.

I'm looking for help on where to introduce the seafoam to the intake manifold as opposed to debating the merits of it. Any help would be greatly appreciated.

 

Are you sure you looked on YouTube? I typed in "N18 Seafoam" and this is the first video that popped up.

 

Yes but the hose he disconnects does not run to the intake manifold. Also the other end of it runs to the cabin.

 

Call Detroit tuned they have seafoam treatment for N18s now. Good luck.

 

This is the line he is using to introduce seafoam into the engine wih

 

I've been waiting for this comment

 

No,, no.. That is the line from the vacuum pump to the brake booster. Doing that will only ruin one or the other.

Inject it into the system with a boost tap adapter at the MAP sensor if you want to run it.

 

Your wasting your time with seafoam at this stage. Plus what are the codes your getting? I just don't think its a carbon problem. Good luck!

 

Thanks that is exactly what I was looking for!

Hopefully I can have this in a few days and it'll get me running properly before I have to dish out large amounts of money

 

Snake oil !!!

 

ClubMINI Queensland in Australia did a Dyno and Carbon Clean day.

Every car that had a carbon clean picked up HP we did before and after runs some gains were significant.

My car went in for warranty work the next week and the intake manifold was removed there was no carbon build up this seafoam is not snake oil the process works.

 

Did you ever order it? Just curious if everything is better now.

 

You could always do the easy one and just put seafoam in with the gas. Mixing Seafoam with fuel has made my motorcycle and 25 year old SUV run like a champ. I mixed it in with the oil to take care of oil deposits which generated a valve tick as well. But I would just start with adding 1/2 bottle to fuel.

 

The S motors are Directed Injected, which means it will never reach the valves. The seafoam would go straight into the cylinder and burn away.

Coincidentally, I changed my plugs this weekend and I need to clean the cylinders! My valves were blasted 12k ago, but the cylinders were caked with carbon.

 

I seriously doubt you're having a carbon build-up issue, the N18's do not suffer the excess carbon build-up like the N14's. I have seen many N18's valves clean with a little discoloration. Sea foam is a waste of time, have a mechanic troubleshoot your Mini. We can guess about what might be wrong all year, most end up spending more money by just replacing what they believe to be defective part.

 

Has anyone here actually removed a spark plug and used a camera to explore the inside of a cylinder? We have a tool where I work called a "see-snake" that can actually go inside thru the spark plug hole, and give a picture on a small screen as to the combustion chamber's condition, and any "buildup" of carbon. Granted, it may not be able to swivel enough to see the valves, but it will give pics of the top of the piston, and the cylinder walls.

 

Now, if one were to use the "see-snake" to go through the intake, or exhaust ports, then maybe some "valve conditions" could be seen. This would obviously involve a bit more disassembly than removing a spark plug. But may be worth a look? Just to confirm or deny carbon buildup as the culprit?

 

If you removed the airbox and manifold MAP sensor you have a 12mm hole to go through to check the back of the intake valves.