Carbon removal

[Buick35]

I pulled the spark plugs yesterday and noticed that they were badly carbon fouled.What's a good way to remove carbon from the cylinder head? Straight eight Buick.Thanks.I really don't want to pull the head.

Edited August 7 by Buick35
Spelling (see edit history)

[Pete O]

I've read in places that if you SLOWLY trickle some water into the carburetor while the engine is all warmed up and running at a fast idle that the steam produced in the cylinders will clean off the carbon.  I don't know from first hand experience if this works or not.

[Buick35]

It might be worth a try.Thanks

[JFranklin]

The water trick was described in my high school auto shop. The engine gets a trickle for a short while and then slowly more until it dies. Leave it sit until the next day and start it up. The teacher said do it outside and don't stand behind the car with clean pants on! You want to do this carefully and not hydrolock the engine.

[keiser31]

3 hours ago, Pete O said:

I've read in places that if you SLOWLY trickle some water into the carburetor while the engine is all warmed up and running at a fast idle that the steam produced in the cylinders will clean off the carbon.  I don't know from first hand experience if this works or not.

I have seen it work.

[Larry Schramm]

Us this stuff. GM Top engine cleaner.  Like the water suggestion pour in slowly into a warm until engine stalls and then let sit overnight.  Should not need more that 1/2 of a quart.

 

https://www.amazon.com/ACDelco-10-3015-Engine-Injector-Cleaner/dp/B07CZ17LK3/ref=asc_df_B07CZ17LK3/?tag=hyprod-20&linkCode=df0&hvadid=693070740373&hvpos=&hvnetw=g&hvrand=16516057993375027590&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9012362&hvtargid=pla-593419173314&psc=1&mcid=f4d05de150aa3273a58e938301b93e06&gad_source=1

[Pfeil]

1 hour ago, Larry Schramm said:

Us this stuff. GM Top engine cleaner.  Like the water suggestion pour in slowly into a warm until engine stalls and then let sit overnight.  Should not need more that 1/2 of a quart.

 

https://www.amazon.com/ACDelco-10-3015-Engine-Injector-Cleaner/dp/B07CZ17LK3/ref=asc_df_B07CZ17LK3/?tag=hyprod-20&linkCode=df0&hvadid=693070740373&hvpos=&hvnetw=g&hvrand=16516057993375027590&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9012362&hvtargid=pla-593419173314&psc=1&mcid=f4d05de150aa3273a58e938301b93e06&gad_source=1

Disconnect your catalytic converter first if your car has one.

[Pfeil]

8oz. glass, 4oz water, 4oz ATF. Pour slowly with engine running at 2500-3000 rpm and do not let the engine die-if you do that you could hydro lock the engine. So, one hand on the glass and one hand on the throttle to modulate the 2500-3000 rpm. Disconnect catalytic converter from cars that have them.  

[TerryB]

It’s a straight 8 Buick according to his post so no cat to worry about.

Edited August 7 by TerryB (see edit history)

[Tom C]

I recall reading an extensive article about this subject in Hemmings.

They used a product called Run-Rite. 

[plymouthcranbrook]

2 hours ago, Larry Schramm said:

Us this stuff. GM Top engine cleaner.  Like the water suggestion pour in slowly into a warm until engine stalls and then let sit overnight.  Should not need more that 1/2 of a quart.

 

https://www.amazon.com/ACDelco-10-3015-Engine-Injector-Cleaner/dp/B07CZ17LK3/ref=asc_df_B07CZ17LK3/?tag=hyprod-20&linkCode=df0&hvadid=693070740373&hvpos=&hvnetw=g&hvrand=16516057993375027590&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9012362&hvtargid=pla-593419173314&psc=1&mcid=f4d05de150aa3273a58e938301b93e06&gad_source=1

I used that years ago on a Chevy 350. It definitely ran better afterwards.

[pfloro]

Whether or not you use an initial "treatment" to remove the carbon, I highly recommend Mix-I-Go.  I have used it for 35 years in several modern and not so modern vehicles.  By adding 1-2 oz. to 10 gallons of gasoline, the product will slowly remove the carbon and keep it from building up again.  It may take several hundred miles or more to initially remove the carbon so you need to use it after every fill up and be patient.  Initially, I was skeptical back in 1989 when I used it in my 1984 Toronado.  It had developed a rough idle and the 307 V8 was pinging.  It took some time but the improvement was truly amazing.  The idle smoothed out, the pinging disappeared, and overall performance improved.  I was able to continue using 87 octane fuel...

 

I use it in my 2011 Corolla (55,000 miles).  The little 4 cylinder engine idles so smoothly (in gear or out), I sometimes think that it's an 8 cylinder...!  The combustion chambers, intake valves, and injectors are carbon & deposit free. 

 

Paul

 

 

Edited August 8 by pfloro (see edit history)

[Rusty_OToole]

Years ago I made a gadget out of a windshield washer bottle, pump, and nozzle. I could slip the nozzle under the air cleaner lid and squirt water into the carb as I drove down the road. It was powered by a wire from the cigarette lighter. If I used it again I would reduce the amount of water but other than that it worked great. I don't know how effective it was as I didn't take the engine apart. It was just something to fool around with.

[Frank DuVal]

I use water to clean carbon. I DO NOT let the engine stop. That is good for hydro-lock, which is bad for pistons and rods. Also, it does no good to leave water sit in an engine overnight! RUST!

 

Now, GM Top Engine Cleaner does do work when left in the engine overnight. It is solvent based (yes, I know, water is the universal solvent...🤣). I used it one time, and yes, lots of black smoke out the next day!

 

I do the water trick before I tear an engine down if I can, makes stuff inside the combustion chamber clean.😉

[JACK M]

BRP OEM ENGINE TUNER - 0777189 | Boats.net

 

This stuff, I used it quite a bit when I worked on boats.

A local pot lot was my best retail customer for this stuff, they bought it regularly and were amazed how well it worked on their junkers.

As suggested hold the high idle and slowly pour it down the throat until you can't stand the smoke.

Let it sit overnight and then kill some more mosquitoes in the morning.

Great tune up in a can.

[LARRYCAROL]

I remember a lot of techs using Seafoam additives. In tank or hooked up to a vacuum line. I tried it on my van through vacuum line and it smoked a lot, took long drive up highway after to clear it all out. I also remember Chevy field rep pouring water down carb  on a v8 with a knock! He said if it didn’t fix it he would authorize a new motor 😃

[ABear]

On 8/7/2024 at 10:17 AM, Buick35 said:

I pulled the spark plugs yesterday and noticed that they were badly carbon fouled.What's a good way to remove carbon from the cylinder head? Straight eight Buick.Thanks.I really don't want to pull the head.

Ok, I have been down this road more than once.

 

My Dad was the pour some oil down the carb and rev the engine until no more oil smoke..

 

On edit for clarity..

 

I DO NOT DO THIS, NOR DO I ADVOCATE ANYONE TO POUR ANY LIQUID OF ANY TYPE INTO A ENGINE WHETHER RUNNING OR NON RUNNING, PERIOD.

 

Honestly, however, pretty much everything mentioned in this thread can and does have potential to create far more damage to your engine and much less "benefit of cleaning" than a fouled spark plug.

 

To me, the potential damage to your engine far, far outweighs any possible actual "witches brew" brew possible benefit poured into your carb.

 

Carbon build up on the inside of the cylinder as one of my oil well Hit and miss engine friends have told me is one of the worlds strongest known substances, once there, it is as hard as diamonds and pretty much takes mechanical removal unless it builds up to the point it breaks off and now you have a hard chunk of diamond strength abrasive running around your cylinder. Water/steam and most chemicals will not touch it, it is not broken down easily.

 

If you do not believe me, take that plug and try steam cleaning it. Then try immersing in water, then try all of the other chemical methods. The only thing I have found has been mechanical scraping, but unless you FIX the reason why it was there in the first place, it WILL COME BACK.

 

Even IF you could "remove" the carbon fouling, it WILL COME BACK. It is there for a reason, you can READ the plugs condition, there are charts which show types of carbon fouling with can help pin down the problem without taking risky "fixes".

 

Here is a quick primer on spark plug fouling..

 

https://mechanicbase.com/engine/fouled-spark-plugs/

 

Top two reasons below..

 

"Causes of Fouled Spark Plugs

Fouled spark plugs are usually caused by internal oil leaks into the combustion chamber, such as leaking valve seals or piston rings. It can also be due simply to age if they weren’t replaced when they were due after the service schedule.

 

1. Oil Contamination in Combustion Chamber

One of the main reasons for the fouled plug is oil contamination. When oil leaks into the combustion chamber, the tip of the plugs gets contaminated, leading to failure.

This problem occurs more often in older vehicles. However, you can catch the issue early on if you notice the vehicle is burning through oil faster than normal.

READ MORE: Why Is My Car’s Engine Burning Oil? (& How To Fix It)

 

2. Carbon Buildup

If the insulator tip or electrodes of the spark plug are black with dry soot, the issue could be carbon buildup. However, the reasons behind the carbon buildup can vary.

It’s possible that the air filter is dirty, leading to contamination. You could also be spending more time driving at slower speeds, changing how the combustion occurs. It also happens if the fuel injectors become dirty or you idle the vehicle excessively."

 

My suggestion:

 

Your plugs may just need replaced, replace them and gap them properly.

 

Just because the plugs have carbon fouling, it doesn't mean the entire cylinder/head/valves are loaded with carbon.

 

Then drive and observe the condition of the plugs at regular mileage intervals, noting condition at each interval for each plug. Then you can determine if there is other issues with each cylinder that may eventually lead to proper action down the road.

 

Using correct plug, plug heat range and gap on new plugs may solve the problem without all of the need of resorting to old school backyard mechanic hacks that are risky at best.

 

Here is a nice picture chart of spark plug types of fouling and the typical causes in the link below..

 

https://ngksparkplugs.com/en/resources/read-spark-plug

 

Edited August 9 by ABear (see edit history)

[Frank DuVal]

8 hours ago, ABear said:

My Dad was the pour some oil down the carb and rev the engine until no more oil smoke..

Wait, why? Oil just adds to the carbon build up.😮

 

8 hours ago, ABear said:

To me, the potential damage to your engine far, far outweighs any possible actual "witches brew" brew possible benefit poured into your carb.

Water is not a witch's brew, in fact you can drink it!🤣

 

GM Top Engine Cleaner has been in the GM arsenal of tools for well over 50 years, might be a witch's brew, but has stood the test of time!

 

8 hours ago, ABear said:

Carbon build up on the inside of the cylinder as one of my oil well Hit and miss engine friends have told me is one of the worlds strongest known substances, once there, it is as hard as diamonds and pretty much takes mechanical removal unless it builds up to the point it breaks off and now you have a hard chunk of diamond strength abrasive running around your cylinder. Water/steam and most chemicals will not touch it, it is not broken down easily.

I see you have not actually tried using water down the carb of a car engine, or you  would not say this. Steam is quite a powerful cleaner. Sure, who would steam clean a spark plug outside of the cylinder? Hard to hold a plug while using real steam, much easier to let the cylinder hold it and let the engine produce real steam, not hot water.

 

Still not convinced I see, not going to change YOUR mind....  But keep in mind when engines are torn down that had coolant leaks into the combustion chamber it is real easy to spot, as the coolant has REMOVED THE CARBON in the area of the leak! I've seen it myself. That's why I started using the water trick before tearing an engine down to rebuild it. Much easier to remove the carbon that way than to scrape scrape scrape!

 

Yes, one does need to correct the reason for fouled plugs, as if not then cleaning will be short lived. 😉

[60FlatTop]

10 hours ago, Frank DuVal said:

Yes, one does need to correct the reason for fouled plugs, as if not then cleaning will be short lived. 😉

As I read down through the replies this kept coming into my mind. Incomplete combustion or incorrect fuel mixture is at the bottom of it. I would start with an infrared thermometer all over that engine at operating temperature and on to a compression test.

[ABear]

12 hours ago, Frank DuVal said:

Wait, why? Oil just adds to the carbon build up.😮

 

My Dad was born in the 1920s, grew up in the oil patches of PA, was steeped well in all the old backwoods oil country bush fixes. Very smart, independent advanced thinker who worked in a oil refinery for his entire working career.

 

While I don't know the exact reasoning as to why oil, I do know that pretty much every single bottled carbon removing "fix" that you can buy off the shelf CONTAINS OIL or derivatives of OIL (AKA "Petroleum Distillates").

 

Today, we have access to a lot of technical information via MSDS or SDS Safety documents that manufacturers must provide access to.

 

For instance a very popular, well known "does all" product called "SeaFoam" which is used to "cure" everything engine related ills, MSDS paperwork shows it is 95% Hydrocarbon Blend. Hydrocarbon is another name for "Petroleum Distillates" which can be derived from crude oil and natural gas. It also Contains Isopropanol alcohol.

 

 

https://seafoamworks.com/wp-content/uploads/2017/01/Sea-Foam-Motor-Treatment-SDS-v20161205-ENG.pdf

 

13 hours ago, Frank DuVal said:

Water is not a witch's brew, in fact you can drink it!🤣

To an engine, direct water ingestion leads to death.

 

It also is a leading cause of human and animal deaths that were never designed to breath into the lungs.

 

13 hours ago, Frank DuVal said:

I see you have not actually tried using water down the carb of a car engine, or you  would not say this. Steam is quite a powerful cleaner. Sure, who would steam clean a spark plug outside of the cylinder? Hard to hold a plug while using real steam, much easier to let the cylinder hold it and let the engine produce real steam, not hot water.

Water has a super impressive amount of expansion capability when it transitions from liquid to steam.

 

https://www.reference.com/science-technology/ratio-water-steam-e8765e4e16144993

 

"At average atmospheric pressure, the expansion ratio between water in its liquid form and steam is 1:1700. This means that under ideal conditions, 1 part of liquid water expands to 1700 times the volume as steam when boiled.

 

Generally, the expansion of water into steam depends greatly on temperature and atmospheric pressure. When water boils and turns from a liquid into a gas, the gaseous form fills a much larger area. Steam has been an important tool in years of human invention and has been used to power engines or cook food like vegetables or rice. It is most often used to remove wrinkles from clothing."

 

Keeping in mind the pressure inside a running engine already exceeds normal atmospheric pressure of roughly 14 PSI by the compression ratio (5:1-12:1), PLUS the expansion ratio of the fuel flame front burning. Your engine RPM also greatly affects the actual cylinder pressures.

 

Your engine cylinders is a "pressure vessel", as such it has pressure limitations, under normal operation it is well designed, but pouring non compressable liquids directly into it, not so much.

 

So at starting speed a engine with 6:1 compression typically will have about 70 PSI-80PSI but yet that same engine when running at max RPM can have cylinder pressures well above 1000PSI..

 

And yet, you are OK with deliberately dumping some liquid like water in a uncontrolled manor right into a operating engine which now expands 1700 times per part added?

 

You sir, now have a very, very large metal pipe bomb.

 

13 hours ago, Frank DuVal said:

But keep in mind when engines are torn down that had coolant leaks into the combustion chamber it is real easy to spot, as the coolant has REMOVED THE CARBON in the area of the leak! I've seen it myself. That's why I started using the water trick before tearing an engine down to rebuild it. Much easier to remove the carbon that way than to scrape scrape scrape!

It is better to live to "scrape, scrape, scrape" than to have 500 lbs of cast iron and steel shred you to pieces.

 

If the engine does manage to survive, you actually have done yourself a disservice, you actually erased condition information on each cylinder. That information can be used to determine if it just needs rings or if you need rings plus valve guide/head repairs and how bad it is. I would rather have as much information as possible to do the job right the first time!

 

Adding non compressable liquids directly into a operating engine can cause something called "hydro locking", that is a condition where the cylinder receives too much liquid that can not compress, that liquid is the same as ramming the piston right into the head.. Not much survives when that happens.

 

https://rxmechanic.com/hydrolocked-engine/

 

"Should any other fluid enter in large amounts, it can cause a problem known as a hydrolocked engine.

A hydrolocked engine is an engine that has seized due to the ingress of excess water in its cylinder. While water is not supposed to enter the cylinder, a small quantity won’t do much harm. However, when it gets too much, hydrolocking occurs. So how much water to hydrolock an engine? Typically, an amount larger than the volume of the cylinder is enough to do the mischief.

When too much water enters the cylinder, the rotation of the crankshaft will force the piston upward so it compresses the water. However, because the piston cannot compress water like fuel and air, the water inside the cylinder will cause the piston to cease moving. Invariably causing the engine to seize and rendering your car immovable.

Unfortunately, water isn’t the only liquid that can cause hydrolocking. Other fluids that can cause hydrolocking when they enter the cylinder include coolant and oil. Now that you know what causes hydrolocked engine, knowing how do these liquids get into the engine is the call of the time?"

 

In a multi cylinder engine, you have zero control over how much liquid ends up in each cylinder, the cylinders close to the carb will most likely end up with too much liquid and the far cylinders not much. You also do not know the exact amount of oil present in each cylinder which is also not compressable. Making this a rather sketchy and perhaps gutsy, not so smart move at the same time.

 

Something to consider, some light carbon build up within the cylinders is considered normal and causes no harm, in fact it actually raises the compression ratio a tiny bit. This small amount does no harm as long as it stays in check and it self cleans under normal operation by burning off into smaller ash particles as you drive.

 

Very short drives can also be a cause of excessive carbon buildup on the plugs, the engine needs to get "up to operating temp" periodically, so if you take it for a spin to your local store 5 miles away on a regular basis, you may want to take a longer drive to a much longer distance store as part of your routine to get it up to full operating temperature which will do it a world of good for keeping the carbon buildup at a minimum.

 

Excessive carbon build up on plugs is not normal, but it may be a sign of just worn out, oil or gas contaminated plugs, wrong gap, wrong plug heat range, poor spark, cold engine, worn oil rings, worn valve guides or way too short of drive time.

 

Best to replace all plugs with new, properly gapped plugs in perhaps a hotter heat range and then periodically access the condition of the plugs on a regular basis to get a good read on each cylinder. Once you have good logical information you can then figure out if other corrective actions need to be done.

[JACK M]

On 8/8/2024 at 11:55 AM, ABear said:

pour some oil down the carb and rev the engine until no more oil smoke..

This right here makes no sense.

And you contradict yourself by pouring in non-compressible liquid oil.

[ABear]

6 minutes ago, JACK M said:

This right here makes no sense.

And you contradict yourself by pouring in non-compressible liquid oil.

AND once again, I do not do that, that was my Dad..

 

And once again, EVERY single commercially sold carbon deposit remover is made up of at least 50% or greater  in OIL.

 

Perhaps some reading comprehension is needed on folks part?

 

Read every word in order, s l o w l y instead of skipping and speed reading in things that I never said I do.

[JACK M]

1 hour ago, ABear said:

Very smart, independent advanced thinker 

 

[ABear]

4 minutes ago, JACK M said:

 

He did teach me a lot, much of the knowledge I have he taught me, but I have taken a lot of knowledge and built on what he taught and showed me. As I learned, I realized there were often things he taught me that were not always in the best interest and there are much better ways to do some of the things he taught me that were much more scientific and a lot less "experimental".

 

And I have gone back and added a very large bolded disclaimer that I do not pour any liquids into a engine as my Dad did..

[Frank DuVal]

I will continue to pour that deadly water into my engines, after all , better do that than breathe it in and die. 🤣🤣🤣 No more plastic water bottles in the garage to quinch my thirst, I might die from misusing it by breathing it, glad you set me straight! 😮❗

 

Nice long explanation for a non-existent problem there. Lots of engineering mumbo jumbo from someone who has no experience doing the task. I could write similar warnings about anything one does everyday. Shaving? You could loose an ear. Drinking liquids? You might drown. And don't get me started on using heating appliances to cook a meal. Especially that one using a Magnetron to make RF of 2.45 GHz at 1 killowatt!😮 Sure, all these things are possible, but with following directions danger is avoided.

 

No one said to pour water or GM top engine cleaner in quickly. One has to follow the directions. The worst thing that can happen is Hydrolock, and that can damage pistons and rods. That would be an expensive mistake, but no personal danger, until your wife finds out how much it will cost to fix! ❗🤣  If there was explosion danger of water being put into a combustion chamber, then every head gasket leaking into a cylinder would have dire consequences and shrapnel guards would have to be mandated to be installed on all engines.😮

 

Petroleum distillates are just that, light products that are more solvent than motor oil. You didn't say your father poured petroleum distillates into the engine. 😉 If he did, he may have been smarter that you give him credit for!😃

 

Go ahead and ignore people who actually do this work with great results, (how many cans of GM top engine cleaner do you think have sold in 50+ years?)  but don't tell us we are wrong in our known results. It's a free country and we do not all believe the same things. Sort of the definition of a free country!😉

 

Have a nice day!😊

[60FlatTop]

Looks like this topic is heading for that dihydrogen monoxide impasse. Mixing that with high concentrations of nitrogen laced with hydrocarbons is a delicate balancing act, not to be treated lightly.

[Frank DuVal]

Exactly!👍