Removing Carbon From Piston, Cylinder Walls, and Block Deck 

Here in the jungle in Costa Rica we do not have much, but we do have WD-40. Your method worked perfectly on my 10 year-old Niva. I can read the piston stamps as clear as new! You are too humble.

I am not a mechanic although I worked on my own cars in the 70's and 80's. Here is a tip I always remembered from my father. You can build a grease dam around each Piston crown at the sleave when removing carbon. This will help with debree getting down between the crown. Then when done move the Piston a little down and wipe the wall and piston clean.

A trick that I read about online, that I have used with good results, is to smear a little grease on the cylinder wall, then rotate the crank so that the piston pushes the grease to the top of the cylinder, then let the piston go back down. Any dust, dirt or debris that has fallen into the piston/cylinder gap will get stuck in the grease! Now you can simply wipe the ring of grease out of the cylinder taking any crud with it :)

Wow, that came out looking amazing, especially for a first pass! I think there's a lot of value in showing things not brought to absolute perfection. For the DIY folks, as well as for techs new to the industry, it can be difficult to get a feel for what's "okay," and what isn't. Experience is the best teacher, but example comes in a close second! :)

A classic Charles Humble Mechanic video, this is exactly what I watch to teach myself to be a better mechanic being not formally trained.

Nice production values - great lighting and camera work. Looks a lot easier than the engine project I did without WD. I used a metal stripper and the fumes were nasty.

Great video! I love how you break every step of your work down and keep it simple while informative. Keep it up HumbleMechanic!

Thank you for making this video. It's full of important information that a first-time engine-fixer like me really needs to hear.

I have met other "so called" mechanics that could do an engine "overhaul" in three hours. It took me three hours just to get the engine out and stripped down. Then started the cleaning!!!

I always used brake cleaner on piston tops and the block deck. Never thought about WD-40 for that purpose. Awesome video!

Charles, I learn something new from each of your videos. Much appreciated! I also particularly like how you explain the possible alternate methods that could be utilized if the tools are available.

I pretty much watch all your vids just to try and understand how your so calm, cool, and collected. I just got the heads of my 5.3 in my work truck and every single chevy forum said to never scrape or use the scotch bright. But I trust you more than I trust them.

The one time that I'd be thankful to have a 4-cylinder engine. Less work...

I'd use a lacquer thinner to dissolve the carbon first. It will clean off faster with no scraping. Using WD40 AFTER that does seem like a good idea. I have decarboned many 2-stroke airplane engines and have never used any kind of scraper. Just shop towels. NO scrape marks anywhere!

just as a matter of interested, the complete meaning of WD-40 is water displacement formula #40, as that formula was obviously the 40th attempt at an H2O displacement product. I totally dig your videos. Well presented with no unnecessary rambling about whatever, to the point with great info. I'd never seen nor heard of the WD-40 and Scotch Brite on the piston tops. Superb idea. Thanks and keep up the great vid's.

I have always used an air angle die grinder with a cookie (scotchbrite) wheel to clean up blocks and heads.I have never had the patience to try to clean up M.L.S. gasket from an Engine.I give you credit for that.Even though I'm not a VW guy,I love seeing any type of major Engine work done.Great Videos!

great tips! when i restored my old vintage Lamborghini tractor engine i had to took off a lot of built carbon from the cylinder head. unfortunately i didn't know this method with DW40. thanks man!

I think you should mention that depending on the material the block is made from, different tools and techniques should be used to prevent damage to the mating surfaces of aluminium blocks.

Excellent video man! Super informative and clear as water to understand everything you need to know for cleaning this surfaces

great video! I love sped up footage and the time lapse you did. it's neat to not miss anything and still have a reasonably short video!

As a qualified motor engineer with 50 years on my clock, might I ask about the piston rings ? This is a 140,000+mile, engine. I agree that the cylinder bore 'cross hatching' marks being visible indicate limited wear & assuming there are no vertical plane scoring marks present then everything down the bores is all OK. However ! (There's always a however) on my vast and comprehensive experience with bashing engines with hammers, I would like to point out the fact that 9 out of 10 engines that I have stripped have the piston rings stuck in the piston lands. The piston rings in most cases need to be removed, sometimes even broken to remove them from the piston. I ask, if the 'crosshatch' marks are visible and there's a 'within tolerence' 'Bore step' on this high mileage engine, would it not be prudent to assume that the piston rings have stuck, thereby causing excessive oil consumption etc. and as you've gone the trouble of half stripping the engine, to remove the piston & conrod assemblies ? I know its a can of worms but at high mileage, the crank bearings might be well worn. I understand that this video deals with block levelling but attention is being given to the bore condition & I thought my input might be of some help. Respectfully. Not a criticism, just observations based on a career lifetime of engine rebuild fails ! Nice informative video by the way. My respects, Johns MG Rover parts.

Thanks for the tips man! Just got a 68 corvair engine to put in a dune buggy...the engine is dirty! There was no water inside too!

I used this trick on my SBC pistons and it worked great! Thank you sir!

I have enjoyed your videos for some time now. Thank you for continuing the content and good luck with the career modification.

Watching you scrape the block with that scraper, putting gouges in it, and then using a Scotch Bright, makes my heart sink. To each their own.

5:55 "Dont press down too hard, we dont want to take scrape off any metal" *makes a fat scratch in the metal*

I've tried literally everything and I always go back to WD-40 good video!

All I have to say is thank you so much. I have never been able to clean the top of pictures as well as you did in this video. I know this is an older video and you might not ever see my comment but I still wanted to thank you for sharing. I also love that WD-40 spray bottle. I could not even guess how many times I have sprayed myself in the face with the aerosol can. Again thank you for your time all sharing this with all of us and it will definitely come in handy for me. I have 2 Motor jobs sitting outside my garage and I'm definitely using your technique.

I love how 95% of people who have posted NO informational posting on auto repairs chirp up about someone else's shortcoming after sitting back int their Directors chair pointing every little thing "wrong" with this post. Sweep off your own front porch and thanks for posting Charles.

Nice & one of the better video's!

This is awesome, great to see you doing the work firsthand

I did this on my XJ's I6 engine a few months ago with nearly 200k miles on it. It definitely is as easy as your video shows. Felt good to clean all that build up off.

What provision do you have for removal of the deposits that make their way through the gap(aided by liquid)and in behind the rings. ?..,especially the top ring ? I am concerned that since cylinders all wear more up top, the crud will make a tight situation, especially at the bottom,since it has flowed in under the rings.Myself,(and I usually work on slow ,non performance antique engines)I was taught to neck down your shop vac hose and GENTLY scrape it loose still DRY , and vacuum it out as soon as it comes loose .You can tape the hose to scraper 1/2 "inch from the end and the suction will offset gravity. (carbon is abrasive).

As a machinist, DO NOT use an air or electric powered grinder / sander with a roll lock disc! You can not keep the disc straight when sanding. You always end up with low spots in the deck surface or rounded corners of water jackets and bores!

also having done turbines , using a nice flat stone to surface your block is also nice little trick , i learned from doing millwright work in the past ,,,thanks for sharing ,,,cleanliness is godliness LOL

I like that spray bottle that you had with the WD-40. Years ago I came across a shop size aerosol can that sprays so much out with just the little push on the top it covers everything quickly. I have probably had that can for 10 years and I'm still have more than half of it. I usually use it to stop flash rust. It comes in handy when rebuilding a motor. Which in a few weeks I plan on starting. It's going to be my winter project. Thank you for all the information you provided in your video. The stuff underneath the head on the engine block is almost like concrete. Your way looks so much better and I'd like that scraper you are using. Thanks again for sharing your video.

yo guys. wd40 is a great and reliable product. it's great to prevent rust on items you're leaving sit for a long time, clean tools, get rust off, clean grease. it is not however a lubricant, any beginner hobby mechanic knows this. the best part is it flashes off exhaust and such with less smelly smoke than most other cleaners or nut looseners. that said, why are people bitching about him using wd40 for this job? it's a great product for said task lol.

How I love the sweet smell of WD-40 in the morning...

Dude that gasket scraper is a hell of a tool man thanks for the tip!!!!!

Ive always dreaded this part of the job. WELL NO MORE. I had no idea WD40 would break the carbon up so easily. Thanks for the tip brother.

good video.

I like it when you go into turbo mode.

those pistons look great and everything looks new again. everything I've come to expect of wd-40 products, sweet collaboration

Good stuff. Thank for not wasting time showing us how to build a "high performance" build

would pouring drops of water into the intake while the engine is idling have the same effect? it seems that manually doing it like that is more effective but I am not really inclined to disassemble my engine right now

I didn't realize that WD-40 had so many uses , that head came up like new .

As a furniture carpenter i learned to slightly sand the corners of a scraper to save the scraped surface from scratches.

Nice job explaining things,thanks for sharing.

Charles aren't you concerned that bolting a the head on with the valves making a nice tight seal that you will induce blow by past the old tings & bore? Or did you do a leak-down test to confirm the rings were good. Thanks for these very informative videos, keep them coming.

I wouldn't have thought to use WD40 to loosen up the carbon; I was going to use carb cleaner. - Steve

Great tech tip. I've been an engine builder for decades. It's always nice to learn something new. As for the scraper, I no longer see my Snap On guy. I did find out that the Bluepoint scraper is mand by Bahco. I bought one on Amazon. Thanks again for the info.

Watched your video and tried your method on a Moto Guzzi head and piston, came up really well, I didn't know that WD40 could do this so well. Big Thanks for the tip.

ALL HAIL THE GREEEEEEN SCRUBBY!

How much of that SB pad are you leaving between the cylinder wall & piston top & in the ring groove ? You know there's been many TSBs saying to not use SB disks but SB is SB. "Scotch-Brite is a line of abrasive cleaning pads produced by 3M. The original product line consisted of spun polypropylene fiber with about nine grit variations. Scotch-Brite also contains "Alox", which is a trade name for aluminum oxide." & "Aluminium oxide is used for its hardness and strength. It is widely used as an abrasive, including as a much less expensive substitute for industrial diamond"

Love these videos, useful info, and practical.

WOW a VR6 engine from the inside. Great work.

You should call Discovery's Fast N Loud's and be a fill in for Aaron Kaufman

If your air compressor can't run a roloc, put it on an electric drill!

Wd-40 learn something new everyday I learned about you through the etcg1 video you recently did glad to have found your channel.

fantastic video great reference for future... I'm looking forward to the head gasket replacement video.

this reminds me of a jafromobile video

Easy Off oven cleaner works amazingly for that application

Another great video on the wookie - keep them coming, love this series! :)

Cheers! Will use some of these techniques over the weekend

Soaking in paraffin / kerosene overnight will dissolve that carbon and make it easier to wipe away with minimal effort using your method.

VR6!

Forget like, love your videos man !!! highly professional and so well layed out!

Lots of great information in this vid. Over the years I’ve found hot soapy water works great for carbon deposits. I’m not recommending in this particular case, but if you’ve got parts off that have carbon deposits on them that needs to come off, try soaking them in hot soapy water. You’ll be amazed at how fast and easy the carbon comes off. It does have to soak for a bit, but man, sparkling clean.

I work on Navy ships, and some things need to be stoned smooth and flat. NOTHING works as good as WD-40.

i trashed my car engine for the whole life of it, around 350,000 KMs, when time to rebuild it came, head removed and no carbon what so ever was found inside!

Loved this video , its so satisfying to clean all that carbon

Awesome video, Charles. I'm going to do the same on my VW Golf AVH 2.0 engine today. I have engine on stand already.

for god's sake man, blink, you're freaking me out! BLINK, DAMN YOU, BLINK!

why engineers hate mechanics

Very informative, amazing job!

Thank you for this great video. Looks great. Lots of useful tips.

If your working on an older engine sometimes the head gaskets contained asbestos so it might be a good idea to wear a respirator when cleaning the surfaces.

Ive worked in a machine shop for 11+ years and the worst thing you can do is take a roloc or buzz wheel to clean a deck surface.. this is common practice in "mechanics shops" and that makes me sick and such a horrible technique is in constant use... ps lacquer thinner and a rag will take that carbon off faster and safer than Getting SB debris inside the chamber

Learnt something new, thanks for sharing, will use this advice on my ford cvh rebuild.

Great tips / excellent job / nice video. Many thanks!

A good way to ruin a motor. Scotch-brite is aluminum oxide which is incredibility hard and if you get that inside the motor it will be toast in no time.

I can almost smell the wd40

Very informative. Thank you.

I like the way you explain everything step by step I really love ya 🥰✌🏼

I usually just spray water in the throttle body at roughly half throttle. Cleans pistons safely and effectively.

Rotary brass wire brush and electric drill

Fantastic work. Looks good as new!

Great video man, never thought about using WD-40. I always used carb cleaner sprayed on either a tooth brush or the scotch brute. Mind you I never sprayed carb cleaner directly on the block or in the cylinders.

5:56 NOOOOOOO scratchhh

I think its safe to say if someone was building a 1000 hp engine they wouldnt be here watching this as an instruction video lol im just worming my way thru you tube only reason im watching

Great video brother. Thank God for you.

I am sure that there could be micro fibre that destroy oil pump etc but I really appreciated the clear presentation and common sense comments Hes got a funny acsent :) Regards Keith Tait Perth Australia

After watching this video and reading around to do my own head gasket, I'm finding lots of warnings about the dangers of using Scotch Brite for any kind of engine surface prep. Apparently, it's practically impossible to get all of the Scotch Brite particles out of the engine, and the aluminum oxide abrasive will destroy the bearings and basically anything else that moves and has tight tolerances 😬 There are apparently technical service bulletins out there about this, but this explanation makes enough sense to me that I'll be pursuing other means: www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=563163

5:57 exactly why you don't want to scrape your deck surface like that. Watch him scratch it.....

Nice man, i'm learning a lot here. I'm not a mechanic but like you explain it -everybody can do this.

The best thing I have found for this task is Chore Boy Stainless Steel scrubbing pads. These pads are like steel wool pads, but instead it is a thin, narrow, tighly coiled SS ribbon formed into a pad.These are made for cleaning cooked on crud on frying pans and such. They cut through the carbon like it was butter, and are non-abrasive, unlike Scotchbrite pads. I cleaned the carbon build up in the cylinders and on the pistons on my Kia 4-banger that I am working on, and it took no time at all.

4:48 look at those scotchbrite fibers fly!!! into the engine you go! burn up those main bearings, wheeee!

Good tip here .DO NOT EVER SCRAP WITH A METAL OBJECT ON ANY ENGINE PART. take a plastic one its most safer to use then metal.metal makes deep sratch on the surface you work on

Awesome. Had no idea WD40 could be used for carbon removal. Beats using some fancy expensive concoction. Thanks for that.

This man does not blink. Great vid though man