Carbon on pistons???

[01TrueBluegt]

I recently got my car dyno tuned and the guy dez said that i have carbon on my pistons>, How do i get it off? Is there something i pour in the motor or what?

 

[twogts4us]

The only way to remove carbon buildup off of the pistons is by removing the heads. Any of that crap you pour in the motor has a better chance of doing more harm than good.
But what brought your tuner to make this assessment?

 

[RysRed96GT]

yeah, only way to get it off is to remove the head. i had to use a drill and a wire brush attachment to get it all off. it was baked on there good.

 

[damacman]

I disagree. A friend of mine used to buy Mazda RX-7s with seized rotary engines for cheap. In every case, he said the motor was seized because of carbon build up. He would remove the spark plugs and spray WD-40 into the combustion chambers and let it sit overnight. Typically, the next day the motor would fire right up. [Obviously, he made LOTS of cash buying / reselling RX-7s.]

Back in the days of carburated engines, I would run water down the carb with the engine running and this would also blow out most of the carbon build-up. I just had to hold the throttle open a little ways to prevent the engine from stalling.

You might do a little more research before pulling the heads . . .

 

[FallenPhoenix]

you poured water into a running engine... can you say hydrolock?

That stuff you pour in the gas tank or whatever has a good chance of breaking the carbon up enough to remove it but cause other problems too. I've heard good things about using SeaFoam though

 

[tangerine]

The best stuff to use is either auto matic trans. fluid or gm top engine cleaner. With the top engine cleaner you pour it into you motor and let it sit all night whenever you crank it up in the morning it will blow all of it out. It is some really good stuff.

 

[vidmaster]

water injection kit steam cleans the cylinder walls and pistons when you spray it

 

[damacman]

you poured water into a running engine... can you say hydrolock?

This will not cause hydrolock if done in moderation. I did not advise sticking a garden hose down through the primaries . . .

 

[FallenPhoenix]

This will not cause hydrolock if done in moderation. I did not advise sticking a garden hose down through the primaries . . .

My mental image was of some guy with a bucket of soapy water saying "hey ya'll watch me clean out this here engine."

 

[1992 2.3LX]

i too am curious as to how the tuner cam to the assesment that you have carbon on your pistons??

 

[stangman]

i too am curious as to how the tuner cam to the assesment that you have carbon on your pistons??

 

[damacman]

LOL! Too high of a compression reading can indicate carbon build up.

 

[XtorT'r]

I disagree. A friend of mine used to buy Mazda RX-7s with seized rotary engines for cheap. In every case, he said the motor was seized because of carbon build up. He would remove the spark plugs and spray WD-40 into the combustion chambers and let it sit overnight. Typically, the next day the motor would fire right up. [Obviously, he made LOTS of cash buying / reselling RX-7s.]

Back in the days of carburated engines, I would run water down the carb with the engine running and this would also blow out most of the carbon build-up. I just had to hold the throttle open a little ways to prevent the engine from stalling.

You might do a little more research before pulling the heads . . .

I just had a vision of flying Pi heads.

 

[70stangcoupe]

Water down the carb with the motor running is an older, widely known, popular trick. Obviously, you can't do that on a Mod motor.

No clue how to get carbon off, unfortunately.

 

[geegee]

In the olden days of pushrod V8's, GM used to make a fluid called, "GM Decarbonizing Fluid". This stuff was a petroleum based product something like hydraulic fluid. One warmed the engine, took off the air filter and poured this stuff slowly down the primary venturis of the carb. The result was the car made a hell of a lot of smoke and belched a few times. Examining the ground below the tail pipe area one could find scaled carbon particles.

Since the advent of unleaded gas, carbon doesn't build up like it used to. It was the lead compound in the gas that resulted in the carbon. Like other things of the past this problem has all but disappeared.

Perhaps your tune up specialist is an old guy who still tunes up a car like he did in the 1970's. Perhaps there is no carbon build up at all. Like most diagnosis, its often best to get a second opinion before doing anything drastic.

 

[geegee]

JFWIW, Found this reference on the www...

Decarbanizing.
Carbon buildup can hurt performance, from the knock retard it can induce to the restriction in airflow and improper valve sealing in the combustion chamber. It is a good idea to go through this process as part of your tune up procedure.
Buy a can for top engine cleaner from your GM DEALER (other decarbon fluids dont work as good). You want the liquid, not the spray. This is to be done outdoors ( a lot of smoke will occure). Part # should be 1050002. You can use Marvel Mystery Oil if you are buying an off the shelf product.

Start motor and let it reach normal operating temp.
Find a vaccum hose which has vaccum at all times (with engine running)
Open can
Stick vaccum hose in top engine cleaner
Hold the idle up as the car will try to stall
Let the car suck the fluid into the engine
Dont let the vaccum hose come out of the fluid,as if it does NO DECARBONIZING WILL OCCURE
Let about 90% of the can go into the car and then let it stall
Reconnect vaccum hose to vehicle.
Let it sit for 10 minutes
Start car, car will smoke a lot

Drive around till smoke discontinues (better to try and use 30%, then 40% and then 50% and all the way up to 100% throttle)(meaning that you don't use one set gas pedal pressure).

 

[01TrueBluegt]

when the tuner dyno tuned my car he tried uping the timing but it was detonating and pinging when he set it to high so thats when he said that since i use 93 octane that it causes alot of carbon bulid up and i should get it decarbonized so that he can boost the timing up. But he told me it would be like 150$ to do it and i wanted to find out if i could do it myself

 

[twogts4us]

93 octane causes carbon build up? That's a new one to me. Where is your timing set at now? What mods do you have?

 

[FallenPhoenix]

when the tuner dyno tuned my car he tried uping the timing but it was detonating and pinging when he set it to high so thats when he said that since i use 93 octane that it causes alot of carbon bulid up and i should get it decarbonized so that he can boost the timing up. But he told me it would be like 150$ to do it and i wanted to find out if i could do it myself

sounds like he's making stuff up now. 93 or 87 octane, both have detergents and such to prevent carbon buildup, one won't cause buildup significantly more than the other.

 

[Jake795]

if you don't need the higher octane then the fuel burns slower and this may cause the carbon build up