Engine Carbon Build-Up

[Smitty]

Is there a way to tell if an engine has carbon deposits in the cylinders without removing the head?
How quickly can carbon buildup occur?

Thanks, Steve

[fordfixer]

Remove the spark plugs and shine a flashlight into the cylinder. You should be able to see whats going on.

[Kurt in NJ]

If you run a rich mixture, drive slow and burn oil carbon buildup will be quick, If you have a proper mixture, drive reasonably fast you will probably never have enough carbon to cause a problem.

Looking at the plugs, and with a light inside the cylinder can give you an idea what you have now.

[FRANK PKNY]

I don't think that it is as much of a problem with today's fuel in a tight engine. No lead and cleaner running. I just changed the plugs in my 6cyl jeep at 120,000 miles and they looked clean. Of course it has electronic ingition that helps. In my 35 it's converted to electronic and is an old engine but the plugs come out clean also. I to think you can look in the hole with a light twards the intake valve an mabe get a peek to see if it's got carbon. I have read old motor books that recomended running water in through the carb to help remove carbon but have never tried it. Perhaps some one can chime in on that. Frank pkny

[Jim Parker Toronto]

We used to do that water trick on some of our old V8 flateads, but we never took a head off to see if it really worked, but it must have because we never had any problems even with the stale gas that we got out of the junkers at the wreckers...

[Mitch//pa]

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i used to have a guy come in with a caddy ht4100 motor. every oil change he would come in with a carbon knock. we would pour at least a gallon of water down the throat and he would be good till next time. trans fluid works also but then you end up smoking out the whole neighborhood

[Jake]

Whats the water trick? Please explain!

[Tom Wesenberg]

Originally Posted by Jake

Whats the water trick? Please explain!

Bring the engine up to normal temp, then set the speed to fast idle and slowly pour water down the carb. The water turns to steam and removes the carbon. We also had cans of a GM labeled product that you'd pour in the carb, then the last of the can would be poured in fast enough to kill the engine. Let the engine set while the product worked, then restart the engine and take the car for a drive.

Both methods worked well, and it was best to do this BEFORE the tune up. In the 70's when I worked at the Chevy dealership as a mechanic, I tuned up a customer's car then took it out to test it and to burn out the carbon by running it down the freeway for about 5 miles at 60 MPH. A piece of carbon fouled one of the new spark plugs. That's when I learned if you have a carbon problem, you decarbon before the tune up.

[Patrick L.]

I prefer to put the water in a spray bottle and squirt it in the intake..

[supergnat]

Tom,
Is that cleaning process similar to the Sea foam Deep Creep cleaning process/? I have never tried it and I'm wondering if it would hurt to give it a try.
Supergnat

[Tom Wesenberg]

Originally Posted by supergnat

Tom,
Is that cleaning process similar to the Sea foam Deep Creep cleaning process/? I have never tried it and I'm wondering if it would hurt to give it a try.
Supergnat

I think so. I've heard of using Sea Foam the same way.

As Pat mentioned, with an updraft carb you'll have to use a spray bottle. You could also remove the plugs and pour a little down each cylinder to let it soak, then fire up the engine. I don't recall how long it should soak, but I'd let it set for a few hours.

[Richard in NC]

GM had a product called top cylinder cleaner. That was in the 70's when i was a Chevy mechanic at a small town dealership. It worked like Tom said and was real good. I saw a few cars traded in because they thought the engine was bad when it was a carbon knock. That was high compression engines where the piston would pack the carbon against the head. Also, a lot of people would just take a pepsi bottle and put a couple ounces of kerosene and the rest water. Shake it real vigerous and pour a stream down the carb before the kero and water separate. Shake again and pour some more. Keep on till you have poured the entire 12 ozs in. A stream no larger than a pencil is good, too much can bend con rods, etc.

[Bob from Northport]

There is a product on the market called Techron, made by Chevron.. I have seen test results where regular use in your fuel tank will completely clean carbon off of valves and cylinders. It was introduced in the 80's and is a great product. Don't use the "ProGuard" version. It is simply watered down Techron. Tests are now showing that the new version of Stabil for ethanol used in deisel engine type is also very good in cleaning valves and cylinders, plus takes care of the ethanol problem.

[jrelliott]

Years ago water injection was used to prevent knock. It was also used in War birds for only short times during emergencies. It did clean the carbon out and turned the water to steam. The expansion rate of water to steam is on the order of 1 to 1600.
A neighbor had this injection on a Ford pickup during the 80's when he pulled a fifth wheel and a Crown VIc the exhaust was clean on both vehicles. Pulled air through gallon bottle of water and vapor went into vaccum port of intake manifold on car. Truck had a small water pump attached to a bottler containing water and sprayed the water down carburator, but cannot remember what triggered the pump to start running.

[Jake]

Thanks All for your replys! Jake T.

[Hicktick]

Run your gas tank down to a 1/4 of a tank and add a whole can of seafoam , that will do it .

Oh and drive it but dont run out of gas .