De-carboning the engine?

Question

I recently took my CL to the dealership for a brake job and of course they call me up with a list of other stuff that needs to be done. One of the things they wanted to do is to de-carbon the engine. I use fuel treatments on a fairly regular basis but they told me that it wasn't the same. They want to charge me $124.00 to do this. Is it really necessary or are they trying to blow smoke up my butt?

I have never used anything but premium fuel. I drive the car alot on the highway at greater than posted speeds, so it does get a good blowing out.

The car runs great, there is no pinging at all. I have never heard of high octane fuel burning at a lower temperature. Why would the car be rated for premium if it was going to damage it?

Answer 1

Yea Flyboy, and with a "cheap cigar at that"! I ain't heard of this in 30 yrs. Back before catylitic converters and fuel injectors I saw some guys take and trickle water down the carb while holding the throttle wide open. I ws told that if the engine died during this process the water would cause the engine to seize up. I have also seen transmission fluid poured in the carb the same way. That was somehing to see as it produced so much smoke a neighbor called the fire dept thinking we set the garage on fire. Another good one is they want to charge you to clean the fuel injectors. I ,too use STP gas treatment every other tankful to get the water and some soluable particles out of the system and once a mo. I put in a bottle of Lucas fuel inj. cleaner. That's good enough. Their is a couple of brothers who have a radio talk show and they write an article in the weekend ed. of the newspaper( syndicated column) and they too say fuel inj cleaning is an acronym for cleaning your wallet. So now decarboning is an old trick resurfacing as a new maintenance requirement to "decarboning your wallet"!

Answer 2

Interesting...

We have 3 x Honda/Acura vehicles in our family. My daughter was given the same story by the local Honda dealer re the need to 'decarbonize' her CR-V. The dealers apparently offer a '3-step' process. I also quizzed them about this & that I can buy OTC solutions to clean the throttlebody as well as fuel additives for the 'internals'. And they too stated that their dealership cleaning process is better. Of course, they said the engined was terribly carbonized. Hmmm....

From what I understand, carbon will naturally build to a point. This is because it's safer for manufacturers to factory tune an engine to run slightly 'rich' than it is 'lean' (e.g., hot).

And it is important to use the proper fuel for your engine. The CL (especially the Type S model) runs high compression pistons that necessitates using 91 Octane test or better. That the car's ECM (engine control module) automatically adjusts timing to prevent detonation when using lesser fuels...that unfortunaetly tends to result over time in excessive carbon buildup within the combustion chambers.

The problem with buildup of deposits on the piston heads & cylinder head is that carbon is not a smooth finish like that of raw metal surfaces. Rough points in the carbon surface tend to concentrate heat which in turn can serve as a catalyst for pre-ignition or 'detonation'. And this would be more of an issue if you were running either forced induction or a high compression design, like the Acura does.

However, from how you describe the situation, it would seem that you've taken steps to avoid carbon buildup:

- Use 91 Fuel or better
- Include freeway driving (and occasional spirited accelerations)
- Regularly use fuel additives (STP, etc.)

If you experience no problems with performance, you could just as easily pass on the de-carbonizing treatment, IMO.

I wonder just how much of this is a dealer gimmick to sell a quick 'n easy $124 service add-on?

Answer 3

You can do it yourself by using a product called seafoam that you can buy at any auto parts store. You unplug a vacuum line and while the engine is running you spray the seafoam into the line until the motor stalls. Restart the car and watch as a ton of smoke billows out your exhaust pipe. That smoke is the carbon build up. Try to do it in an open area far from people as it smokes alot. It will only smoke for about 5-10 min depending on the amount of carbon build up you have. I have used this product on my car and noticed it idles smoother. Its much better doing that than paying the dealership a ton of money to do the same thing. Also if you get the RPMs to 5000+ once in a while it will help with burning out some build up.

Answer 4

Master mechanics call that the Wallet Flush. Mechanical De carboning of the intake valves with blast media is only called for when the engine fails to run properly just keep doing what you are doing treatment once in a while and frequent oil changes. Shell Gasoline AD cleans engine gunk. So does a couple full throttle runs.

Answer 5

aaahh...they're blowing something....your engine won't build up carbon if you drive freeway/highway speeds greater than 55 mph.
The only way a car will build up any kind of carbon in the engine, if you're a little old lady driving 2 miles to church on sunday and thats ALL you drive...most cars don't get engine deposits anymore...we drive too much, use better fuels and besides...if it's an Acura their engines are built to last...

Answer 6

Unless the engine is pinging from carbon buildup they are blowing smoke and trying to get your hard earned money.

Answer 7

if there is carbon build up on the piston tops and in the firing chamber it will raise your compression enough to cause ping
on lower octane gasoline's,its not somthing dire unless your having a issue and a basic
decarb can be found cheaper

Answer 8

Quit using premium gas in your low compression engine and you won't have carbon buildup. It burns too cold for your engine.

Answer 9

i've done the water thing. don't just pour it in, trickle it in slowly while you have the rpms at about 2000-3000. seafoam works really well also.

Answer 10

dont not put water on anything!!! thatll **** up your engine
does your car require premium fuel?
try mixing transmission fluid in with your oil itll help remove some carbon build up