I have a friend of the family who ownes a shop and he swears by this. He says that heads can be decarbonized on the engine by pouring a cup of water into the carb or tb while its running at 2/3 WOT. He even does this to customers cars and says that it really works.
I donno... To me, putting water and steam into a cylinder and trying to compress it to 1/10 its origional volume seems to be a highly questionable practice at best.
Any thoughts?

 

yes i've also head this from alot of the older guys, but you used a 60/40 split of water/anti freeze in about 1/2 cup and it will clean out the crap, like if you ever look at the car that had a antifreeze leak that cylinder will be clean as a whistle. mabey siezed, but clean used in small amounts its fine tho

 

Years ago I had a water injection system on a car for this reason.I don't even remember who made it. I don't believe it really did anything. However I do believe if an engine has a carbon knock this is the way to go. The way we did it then was to get the engine hot then pour small amounts of cold water in the carb (note someone has to hold the Throttle at about 2500 rpms)wait till the engine clears up and do it a couple of times. I have not done this in years and have never done it on an injected car. But it will make a difference.

 

It works! I got rid of a spark knock caused by carbon buildup, by gradually dripping a few cups of H2O into the carb on my daily driver V8. Most of the time, I just let it idle as I was dripping in the water.

 

Yeah, I've heard of it too, although I've never tried it. If I remember correctly, pour the water down the carb in little spoonfulls. Pouring a cup of water down the carb all at once might be a bit of a bad idea.

 

Use a squirt bottle, like a windex bottle or something. Just mist it in with the motor revved up. This way you wont dump too much in. You can also use a product called Seafoam. You can get it at napa. You just suck it into the motor through the pcv valve till it stalls. Then wait 15 min and start it up again. It'll smoke so bad for awhile your neighbors might call the fire dept! Then it'll clear up and be fine.

 

I've done this on old engins and it works, but if your going to pour water in any new engine you have to disconnect the cat. I tryed this on my first camaro and about 2hrs later the engine died it took me 2 days to figure out the cat was cloged with carbon chuncks (it was a good excuse to hollow it out with an iron rod )

 

i tried it w/ 2 cups of water and it definatly works... guess ill be eating my words next time i see him

 

Can this type of thing be done to FI car and what is the procedure? thanks

 

One of the best ways I have seen this done with an FI motor is to pull a small vacuum line that goes to the intake manifold and stick it into the bottle of water. Did this recently with a TPI Vette and it worked great. You could see the carbon blowing out the tailpipes! Held the engine at 2500-2800 RPM and stuck the line it. The feed rate was just about perfect- not too fast to make the motor stumble, not so slow that it took all day. Ran about a quart of water through the motor which was HEAVILY carboned up from running badly out of tune for thousands of miles. That's a lot of water and most engines should not need that much. If you do run that much through I'd suggest an oil change immeditately afterwords.

 

Yes, same procedure as above.

 

why would you wanna do an oil change immediately after?

 

Some of the water vapor can leak past the rings and contaminate the oil.


I did it on my motor, worked great. Actually, its in fact about that time to do it again.

Steve

 

is it just plain water that you use?

 

I assume distilled would be the best bet for those who are extremely careful.. but tap would work too.

Patrick DeGrosse Jr.

 

Made a world of difference on my TPI motor when I first got it. I used a squirt bottle, held the throttle open up to about 2500 and kept spraying til the bottle was empty. I figured it would help some when I took off the throttle body and saw all kinds of carbon buildup inside the plenum.

 

It does work, but i wouldnt necesarily do it that way. A spray mist bottle over the carb or into the throttle body will work great. On a fuel injected car, you must not spray it through the MAF, though.