This question is not S2000 specific, but it could apply to the S2000 as well.

After 128K miles on my Accord, I was told that I should de-carbonize the engine. The dealer charges $100 to do it, and I am sure all they do is put some stuff into the gas line and let the engine run for a while. Back when engines had carburetors, I know how to do it, but now it is all fuel injection and there is no easy way to get to the cylinders from the outside.

So is there anything I can pour into the gas tank that would work to de-carbonize the engine? Which one works and which one is a waste of money? Any additional advice? Thanks.

 

Tell your dealer to go to hell.

I'm nto sure where they are getting this from, but there's no "need" to de-carbon your engine.The only thing I've seen in a newer engine that might perform poorly are oxygen sensors, which should be replaced on high mileage vehicles when fuel economy starts to suffer (with a regular tuneup). I haven't heard of any other problems (at least with most imports) that were carbon-related.

If you have an issue with buildup on an injector, your plugs or ECU will tell you by appearance or a MIL (check engine light). Must fuel additives/cleaners will simply gum up oxygen sensors and catalytic converters. I've heard Regane is safe, and I suspect your dealership would do nothing more than throw in a $5 bottle of this stuff. For $100, they can't afford to do much more (than pocket your money).

 

There are some products that you spray into the intake tract (not the fuel). The one I know is used in Subaru vehicles at every service (Subaru branded). I had a car that was badly coked and gummed up in the top end and was pinging severely. One can of this stuff killed the detonation and raised the idle by 500rpm. It most definitely does work, and cost me about ten bucks (that's five of yours).

 

The entrance of choice are the spark plug holes....

 

There is a cleaner called "top engine clean" I picked some up from a local GM dealer and used it on my 3SGTE motor. I blew a turbo seal and was dumping oil into the motor. This stuff work very well all you do is dump a can of this stuff down the intake pipe and let is sit , start the car and a cloud of white smoke will billow from your tailpipe and you done. I recommend changing the oil after the process. I works really well, i checked the piston tops and saw the shiny forged aluminum tops. Made me

best luck
David N.

 

[QUOTE]Originally posted by Davies2k
[B]There is a cleaner called "top engine clean".

 

It's the throttle body. Disconnect the black intake pipe from the filter box to the motor, at the throttle body where the accelerator cable is.

Let me stress that there is no need to do this. Even at 150k miles, there won't be enough carbon anywhere on a EFI motor to even affect performance.

It'll make the parts nice and shiny, but not do a damn for performance.

 

You don't need to do that. Disconnect a vacuum hose from somewhere (anywhere) on the throttle body and spray in half the can with the engine hot but switched off. There should be a little plastic tube that comes with the can to make this easy. Wait 5 mins. Start the engine and spray the remainder in slowly with the engine running. There will be lots of smoke which is normal. You will need to play with the throttle to stop the engine from stalling.

[QUOTE][B]
Let me stress that there is no need to do this. Even at 150k miles, there won't be enough carbon anywhere on a EFI motor to even affect performance.

 

OK, now I know "how" to do it. But the other question is "what" to use. So far, there was mention of some Subaru stuff and some GM stuff, but what about stuff available in auto shops? Is there any brand recommendations? Thanks again.

 

Dave -
If your Mister 2 is still blowing oil past the compressor wheel - run some royal purple. I'll clean those piston domes right up! along with the head, crank, and pan