BE VERY CAREFUL WITH THIS

OK, time to fess up to one of my DIY mistakes (I should put it on the “Admit your stupidity thread, but I hope it will help more here)…

A long, long time ago, probably 20 years or so, I tried this on my car (a Nissan truck at the time). I was having pinging problems, etc, (I don’t really recall all the symptoms), so I tried it.

I started with a spray bottle just misting the water in. It seemed to be OK. I started increasing the amount of water, bit by bit. At some point, I heard a scary loud knock. I stopped squirting water in. From that point on, that engine had a bottom end knock.

I don’t know what happened. I didn’t put near enough water in to hydrolock a cylinder. I used less water than some of the descriptions above. I’m guessing that the water turned to steam and produced enough pressure inside the cylinder to break something, probably scoring a bearing. Remember that a small drop of water can make a big cloud of steam.

I’ve never had the guts to try this again.

I’ve had good luck decarbonizing engines with gas tank additives, like Techron. My current favorite is “Fuel Power.” I have no affiliation with the product; I’m just satisfied with the results. I learned about it here: http://theoildrop.server101.com/ubb/ultimatebb.php
That is a good forum to discuss things like decarbonizing engines. They speak highly of “Fuel Power.” It seems to me that gas tank additives, while being slower to work than introducing something in the intake (either water or a chemical), are probably the safer alternative. Especially when the gas tank additives are added at the “maintenance dose” level, and not the whole bottle to a tank dosage.

Fuel Power: http://www.lubecontrol.com/

l`ve been doing this for years on high milage carburated engines engines with great results.l get the engine good and hot and run the tach up to 3-4000 rpm at which time l introduce the fluid in a steady flow.l find it nessasary to increase the throttle or decrease the fluid to keep the revs up.l use a mixture of solvent and water and after about a liter l choke the motor with the mixture and allow it to sit overnight .Remove the plugs,add some oil into the cylinders and crank to evac any excess fluids.Cha

l`ve been doing this for years on high milage carburated engines engines with great results.l get the engine good and hot and run the tach up to 3-4000 rpm at which time l introduce the fluid in a steady flow.l find it nessasary to increase the throttle or decrease the fluid to keep the revs up.l use a mixture of solvent and water and after about a liter l choke the motor with the mixture and allow it to sit overnight .Remove the plugs,add some oil into the cylinders and crank to evac any excess fluids.Cha

GM had/still has a can of this liquid that has a great rep for this for over 30yrs, if it's still available.
Routine is to pour thru at high rpms, then dump in plenty to stall it, wait an hr, restart.

old cars, small inboard boats, oil burners, rich carbs, etc will have a noticable difference with only water. This GM carbon cleaner is noticably better to someone who has experience with water. I've used both.

I never knew about the cold carbon absorbing water better. I'd do these beat boat engines that would foul plugs every 5-10 hrs.
I'd keep pouring till crap came flying out.

My experience with water and carbon is from water injection I had on my higher mileage 3sgte MR2 turbo. Compression numbers droped after running water injection for a while, and the car ran a lot better.

GM top engine cleaner. Works very well.

I forgot to mention the most fun way to decarbonize an engine: the good ol' Italian Tune-up.

Get the engine all warmed up and then rev the crap out of it (pun intended!)!

Just found this thread, had seen it done a lot back years ago. My mechanic had soda bottles full of water and just poured it in at a rate that would bog the engine. This was before cat converter days.
The expansion rate (explosive rate) is 1608x. Water does not burn, it basically explodes to 1608 times it's size when changing to steam.

I've never done the water, but, I use a product called...get this: De-Carb! I've used for years in boats and my 'burban w/ great results....it tends to foul plugs from what I've heard, but never had any trouble w/it.
S

Works great and is available at your local Cadillac dealer.

been there done that works great.
to see the effects on carbon with water next time you pull an engine apart take a piston or valve and sit it in about a 1/4" of water and see how well it cleans the carbon off. normally the parts look new by morning.i pull the plugs squirt in some water let sit over night crank water from cylinders i caution the walls will be wet with nasty black stuff. install plugs and start engine no damage done and a bore scope will show the difference, i checked just to prove it really was doing something.

i caution turbo guys not to put water in a intake as the high speed spiny thing no likes that.

cheers ed

So since the time of the original post - has anyone tried it on their EFI 911?

Same effect as driving in rainy or humid weather. Unless you're in very dry climates, there's always water vapor in the intake air.

You've received some endorsements. What are you waiting for? Water is free unless you decide on a bottled brand label. Water doesn't care what type of fuel induction system. You weren't going to put water in the fuel tank were you?

Sherwood

I havent done this cause I dont want to screw something up! "Idle minds are the devils workshop" - as the saying goes. Maybe Ill just stick to Gumout etc....

The other reason Im waiting is that the throttle body is a different layout than my other vehicles, maybe someone blazed an easy way to do this on the 993.

Put away the garden hose and start conservatively. Do you have a garden sprayer? Apply a fine mist into the intake at approx. 1200 rpm, same application method as Gumout in the spray can. However, excess solvent in the engine can wash lube oil off of the cylinder walls. NG.

MB even recommends not using excessive amounts of Techron in the gas tank for that reason (also thins out lube oil in the valve guides).

Observe the condition of a spark plug before and after to see the results of your brief decarb. test.

Sherwood

I can attest that water cleans cylinders very well. Which cylinder in the American V8 below you think had a cracked head? ;)

Would I pour water down my intake? Hell no! The risk of vapor locking the SOB is too high IMHO.

A well running EFI car won't build up carbon to the point where it hurts. Just drive it spirited on a regular basis and it will be clean.

George

http://forums.pelicanparts.com/uploa...1287729558.jpg

My dad worked at a GM dealership in the 70s and they had a guy come in with a truck that was severely choked with carbon. They quoted him a price to pull the heads and clean it out but also told him about using water to decarbon it (often referred to as a Coke bottle overhaul). The guy went out to the parking lot and proceeded to dump a jug of water into the carburetor while he had the RPMs wound up. The post mortem lead them to believe that it wasn't hydrolock that bent the valves. It appeared that the massive quantities of carbon buildup all let go at once and the huge chunks of carbon jammed between the piston and valves and that caused the damage.

That does all seem scary but truly heavy carbon buildup is damn near impossible with any modern induction system that will pass smog. I wouldn't want to run a large release of gunk into a cat and I don't know how it might effect a O2 sensor.

I've done this on a number of older cars with a few noticeable results. To do this correctly you need to warm up the car and then wind up the RPMs about halfway up the scale and then pour the water in. A coke bottle will pour it in fast enough. Just turn it upside down and let it glug in.

Is there a good chance that the increased pressure can cause ring damage?