Sorry, none of your tips prevent "valve gunk" on direct injection engines. The cause is completely attributed to the lack of "valve wash" from port injection, as you stated, and the PCV (Positive Crankcase Ventilation) system. The PCV system takes all the vapours created in the engine, blow by etc, and sucks them into the intake manifold (after the throttle valve). These vapours contain several components but basically are combustion gases and oils vapours. Without the "valve wash" that port injection provides, the vapour deposits are what "gum" up the intake valves. There is no service or maintenance scheme that can prevent the build up. In fact many times there is not even a way to reverse the affects without a major engine disassembly or head replacement. Only a "catch can" will reduce or eliminate the build up. A catch can or Air/oil separator, intercept the vapours and condense the oil from the vapours before they enter the intake manifold. Again sorry, your wrong and there is only one solution. Yes good maintenance will ensure a good running engine which ideally produces less blow by etc, but really maintenance is not the solution for DI engines. Factory installed PCV catch cans are. (or aftermarket for the cars that don't have them)

The best fix to gdi issues is trade it in for a car with dual injection.

All three suggestions, which are good maintenance practice anyways, will have almost no effect at the problem at hand. An oil catch can, more specifically a passenger side catch can will filter out any oil being fed back into the intake to be burned off and significantly help in keeping those valves clean.

Solution: Buy a Toyota because they use both port and DI Or.... get and EV

you forgot to mention to use a high-grade full synthetic motor oil which doesn't leave as much gunk behind as do conventional oils.

EGR (exhaust gas recirculation) and PCV (positive crankcase ventilation) systems depend on the vacuum pressure generated by the intake manifold thus drain all their contents into the intake manifold which touches the intake valves anyway. If poorly burnt gasoline and carbon soot from the EGR get recirculated back into the intake manifold along with the blow-by air-fuel mixture and aerosolized engine oil droplets from the PCV system via vacuum hoses then it will not matter what gasoline or engine maintenance you do. The intake valves will foul regardless due to the EGR and PCV system recycling exhaust gases and crankcase pressure into the intake manifold. An oil catch can installed inline into the PCV system will help collect aerosolized oil droplets from the crankcase mitigating intake valve carbon build-up but not eliminate it entirely. Although illegal, venting the EGR directly to atmosphere will help protect your intake valves from fouling. Best advice is to forsake new GDI (gasoline direct injection) engines completely and purchase engines with dual systems that have both port fuel injection and direct fuel injection or just go for port fuel injection systems period. Old technology, although outdated, is still functional in the 21st century. Newer is not always better.

At a time in history when the combustion engine is almost ready for life support (EV's, Hydrogen, etc . . .), direct injection is going to set it back decades in terms of reliability in the mind of consumers and pave the way for the shift away from the combustion engine. We have reached the point where emission requirements have taken priority over longevity and reliability, both of which peaked over a decade ago.

An oil catch can will really help slow down build up on the intake valves.

Every answer for direct injection, requires the owner to buy something, or pay someone to fix it. Wonderful technology

Toyota is now using dual injection. It has direct injection for the main fuel and retains the intake runner injection also.. blends the two for best if both.

This guy does a very good job explaining the unmentionable problem of GDI engines.

There is NOTHING you can do to prevent carbon build up with DI. The build up comes from reversion of the combustion gasses combined with PCV. You can slow it down but not prevent it. That is why a lot of cars are coming out with both DI and Multiport FI.

I prevent carbon buildup by not starting my engine. I have a 2015 Chevy Silverado I bought new in 2015 and have only started it 28x since new. When it is running I put the pedal to the medal at every red light and stop sign. By not starting my engine often I have 285 low miles on my 2015 pickup. Who says you have to use catch cans or run solvents thru the throttle body when all you gotta do is not run your engine. This is why I paid $51k for my GDI Chevy. I want quality for that kind of money and not have to worry about carbon buildup after 1000 miles on my $51,000 truck. Dont be a fool people and ruin your $50k-$75k pickups by starting them up every day and going over 1000 miles. Be smart, spend your hard earned money on an expensive GDI truck like I did then park it. They look good parked and carbon-free. Dont let another big car maker bullshit you anymore. These engines are designed to save our planet and stop global warming. Do your part and buy one

what is the use of saving fuel if the end result costs you more to maintain than the fuel would ever have cost?

Struggling to comprehend how spark plugs, oil changes, and air filter changes serve to delay the build up of crud on your intake valves? Let me shed some light: 1.). Old, worn, mis-gapped, and carbon coated sparkplugs like to misfire when intake manifold vacuum is low, as it is when accelerating. Misfiring plugs allow unburned fuel to wash the cylinder walls, and contaminate the lubricating oil. Fuel contaminated oil quickly loses its viscosity, allowing it become more easily entrained in the crankcase blow by gasses that are directed to the intake system via the Positive Crankcase Ventilation system. RESULT: WORN PLUGS CONTRIBUTE TO VALVE GUNK BUILD-UP. 2.). Infrequent oil changes allow the oil's viscosity to thin, as the polymer additives that are intended to provide "multi-viscosity" properties, break down with age. The "thinning of the oil" allows a greater amount of it to be swept through the PCV system, in a similar way as described with worn sparkplugs above. RESULT:. OLD, THIN OIL ALLOWS INCREASED AMOUNTS OF IT TO BE DIRECTED AT INTAKE VALVES, WHERE IT COLLECTS AS CRUD. 3.). Infrequent air filter changes allow intake manifold vacuum to climb as the filters become clogged. In turn, high manifold vacuum entices crankcase gasses to flow past the clearances between the valve stems and valve guides, and onto the back sides of the valves, causing increased build-up. A poorly maintained vehicle often leads to the combination of overlooked sparkplug changes and oil changes, in addition to overdue air filter changes. Thus, an exacerbated effect occurs when high manifold vacuum acts upon the reduced viscosity oil, thereby undermining the effectiveness of the valve guide seals. RESULT: INCREASED ACCUMULATION OF VALVE GUNK BUILD-UP

STP valve cleaner works amazing. It is a 9 minute spray that you into your valves and I actually took before and after pictures and it worked very well the first time. I also installed an Oil catch separator that I empty every time I do an oil change and that removes a lot of harmful oil residue that creates valve gunk. These maintance tips are absolutely necessary for the new cars with GDI and they do work.

Your best way to prevent gunk on the intake valves is synthetic oil. It requires a higher temperature before it starts to coke. All valves in a internal combustion engine have some oil leak down from the valve stem which moves to the the actual valve seat area. A synthetic oil will resist coking from the high heat of combustion, where a regular oil will coke at a lesser heat producing more gunk on the intake valve near the opening causing restriction of air to the engine making it run like crap. Oil can also get into the intake plenum through PVC systems and settling towards the back engine cylinders intake valves producing deposits on those cylinders.

-Top Grade Fuel -Oil Catch Can -Water Methanol Injection -Go wide open throttle twice a day (on ramps are perfect for this)

Forget about the video, here are the solutions 1. Catch can 2. Fully synthetic oil 3. Pay a TRUSTED mechanic $700 every 40k miles to do walnut blasting (ask for before and after pics if you dont trust the guy) as most of them will spray a little seafoam and charge you full amount

Forth tip: leave your vehicle with direct injected engine parked in your driveway permanently to prevent gunk buildup.

Using a RX catch can and clean side separator since new on my 17 Silverado High Country 6.2L and it calls for premium fuel anyway and you wouldn't believe the gunk that can catches so worth the investment on any direct injection and it doesn't void the warranty.

Main cause is using an oil with a low flash point. What builds up on the valves is oil fumes not oil itself. A catch can is a band aid solution to the problem. Some brands don't have a lot of issues such as DI Chevy engines because they induce a swirl which has proven to keep the intake valves cleaner NOT clean. BMW 335 drivers found out back in 2010 that using a high flash point oil reduced almost completely valve oil fume buildup..I hate being a beta tester for the car industry!

Using extremely clean synthetic oil could help.. Pennzoil Ultra Platinium is made with natural gas which makes it a lot cleaner than other synthetics..

Late to the party but I just got a v6 Caddy and I'm learning about all this stuff. Port injection keeps valves clean by spraying crud off the valve with fuel, but where does that crud go? Directly into the combustion chamber. Seems to me like DI would keep that crud in the valve port since you're not spraying it off into the chamber. I think taking the intake apart every once in awhile for a cleaning is a lot better that replacing piston rings. Then again, it sounds like the PCV system plays a large part in gunk build-up.

Low volatility / NOACK oil (check for MB 229.5 spec if you can't readily find NOACK numbers as that's

Next he will be suggesting to inflate the tyres to correct pressure.

None of this will help if it does not touch the valves

I hear a lot of discussions about the relative merits of 'catch cans'. My question is, if they are so effective, why aren't they routinely used by the manufacturers? I don't know whether they work or not ... I'm just asking the question.

Clean and fresh plugs and top tier gas, please explain how these "indirectly" help valve gunk? I can see a quality motor oil, that may limit oil mist going into the ERG valve, would help keep what does make its way to the backside of the intake valve would help.

That gunk as you call it is blow by from the crankcase, those oil vapors go back to the intake manifold, a catch can will work but needs a one way valve, too much vacuum in the oil pan can reduce oil on cylinder walls, which will cause rings to wear out, and you wont know until a teardown.

One massive thing you forgot: Driving the cars shorter than 10mins at a time, REALLY increases carbon buildup. I had a buddy with a 2007 Passat with the 2.0t. He drove about 5,000 miles a year. He lived just a bit from work, engine temp gauge never reached in the middle. 40,000 miles later, just a couple years ago, he had an engine light, with misfiring, he noticed it was worse on fuel and it ran a bit rough. What I did was take it on a roadtrip across the country. For the first 2 hours, I locked the transmission into 3rd gear so it was revving at about 4,500 rpm on the highway. I filled it up and left it in D. Engine light went away, power is restored and fuel economy is better than he has ever seen it. Carbon will burn off, the combustion chamber just needs to be piping hot to do it.

CRC Valve Cleaner is the solution but don't follow instructions on can. 2017 Sonata new got 32mpg combined. At 25K now gets 26mpg combined. After cleaning, returned to 32mpg and sets you back into the seat @ WOT, so it works. Bring car to operating temp., spray intake (down flow from any MAF) with full spray at 2500rpm. Engine will choke down and almost die, turn off at this point. Let heat soak for 1 hour. Start and drive for a couple miles and repeat twice (3 times total). Engine will crank longer before starting and will rattle and ping first mile of first cleaning. This method only uses 1/3 can for all three heat soaks. The initial pinging proves that carbon was breaking away after each heat soak. No codes set and 5K mile later (30K). Blow-by from crankcase increases with each acceleration and that is why highway use delays carbon buildup. I am a lead foot with WOT used frequently. I will do one heat soak every oil change from now on. GDI problem handled.

WARNING: Don't by a vehicle with a GDI engine. I made this mistake purchasing a Kia 2.0 liter GDI Theta engine (used in both Kia and Hyundai). 144,000 km and the engine self destructed. And this even with regular maintenance. I have also heard the GDI engines with turbos are extremely susceptible to carbon build up. And that using a cleaner can also be very bad because if a deposit lets go it can damage the turbo. Not to mention that the chemicals in the cleaners can damage the turbos by striping the bearings of its lubricants.

Egr valves and crankcase breather valves are to blame!

I installed a catch can on my GDI engines early on. I catch a lot of gunk in the can. I also use CRC intake cleaner at every oil change. I use quality synthetic oil and a factory filter every 4500 miles. So far all is well. Kia and a Buick VVT. One has 30,000 one has 40000. Boroscope shows clean valves. I empty the catch cans every 1000 miles.

No information to help remove the buildup or stop it from forming. The information in this video only helps by not making a bad situation worse.

Screw that. My friend had enough issues with DI. He installed a water injection system. His problem went away! He turns it on every 30 days for one tank. His valves are spotless. So is his pistons... He also uses RXP gas kicker. It removes carbon and prevents carbon build up. To start with... I might add DI vs Port injection. Is not even close to the same. One uses high pressures

Best way to reduce valve deposits: 1. Run quality Syn oil at reasonable oil change intervals 2. Oil catch can 3. Combustion chamber cleaner used occasionally 4. Engine oil flush used occasionally 5. Use valve cleaner spray occasionally or walnut blasting.

Said NOTHING ...

I agree with the plugs especially for the 100K plus replacement intervals. I have 2 Ford vehicles with the EcoBoost DI V6. I changed one set around 12K....new plugs as part of a tune. Looking good still with around 30K on the current set. Changed the other vehicles set the other day at just under 72K. Very pronounced carbon buildup. My other reason for changing more often is to reduce the risk of a plug getting seized in the spark plug well at 100K. Plugs air filter and if accessible fuel filter are three fairly easy and not too overly expensive preventative maintenance items. For the most part they are also fairly easy to complete yourself without paying dealer mark up.

I must say that all your tips (besides the cleaning service at the end) have ABSOLUTELY NOTHING to do with carbon build up in the intake and valves. The carbon build-up is caused by oil return from the crankcase in combination with gases from the EGR system. All these parameters are irrelevant to the "tips" you recommend. Your tips are applicable to a good maintenance of the engine, but will have no effect on carbon build up.

I tell you what works a class action lawsuit,make these thieves pay for their idot engineering fools

Some cars, Toyota, some Subarus, with others to follow, have dual injection system for that very purpose. 1. port injection 2. direct injection. the computer decides when to use each. Problem solved.

Some is caused by crank case oil vapor return into cylinders. Put a catch can and filter in that line .

I don't think this applies to the current Ford 5.0 engine since it has both standard location injectors AND direct injection. Would that be correct?

The only way these tips reduce the amount of gunk build up is by reducing the likelihood and amount of ring blow by, an increase in blow by increases the oil vapours that come out of the crankcase and deposit on the valves. The only real way to prevent gunk buildup is to fit an oil catch can even on a non turbo or diesel engine . Some cars have factory catch cans but they are usually of limited help.

None of those suggestions will make a bit of difference what will work is an oil catch can and for boosted applications i.e.: turbo or supercharged, a dual oil catch can is a must.

I'm surprised he didn't mention a catch can between the crankcase vent and the instake manifold.

Maintenance should be done for every car. Top Tier Fuel will help with the injectors andding a catch can will help but not cure the problem. I have a Lincoln MKS Eco-boost sedan. I have a catch can installed. If you have a Ford Eco-boost in a sedan or truck install of a catch can is very simple to do and you don't need the most expensive one you can buy. Mine was $30 on Amazon with the features I wanted. A bottom drain valve etc. Don't use the breather that comes with it. They reduce vacuum and can mess up your smog check.

Doesn't mention catch-cans.

1) Catch can's will HELP (not eliminate) filter the oily vapors which CONTRIBUTE to oily deposits on the valves 2) VVT will result in soot on valves regardless of catch cans. This is typically less harmful than oily gunk/depositys 3) in addition to catch cans, I say go bigger turbo, tune, water/meth injection+port injection and this will keep your valves clean. But hey, that's just me.

You forgot step 4 get rid of the egr valve and also use a water/meth injection. Also step 5 dont buy a direct injection car.

Good gasoline? Yes. Synthetic oil? Yes. Sparkplugs? NO. (better/full combustion does not help intake valves).

Use seafoam aerosol once a year, that's what I do. Plus if you have a flex fuel run the higher ethenal blended fuels, they burn cleaner than regular gas so the gunk won't build up as quick or at all.

@ 1:38, man you almost gave me a heart attack. I almost thought the "can" was intake cleaner. I'm thinking, man how can he put up with the smell and talk lol...😅 😅 😅

These tips help with other things, but not really for carbon build-up. Ford EcoBoost engines had major issues with this buildup when they were only DI before dual-injected. During the 3.5's development torture tests in the F-150 (there are videos of it on KZfaq) they ran the piss out of it. Constant, prolonged redlining and brutal operating conditions. When they tore it down at an auto show the valves virtually had no carbon build-up at all. I think the best way to prevent gunk is routine Italian Tuneups in combination with quality oil and gas if choosing not to use a catch can. Driving an engine hard for long periods of time will make it so carbon doesn't have time to deposit on the valves.

Use less evaporate oil like amsoil stuff & less SAPS oil > The best I found is Mobil 1 ESP 5w-30 Amsoil Euro 5w-30

So got a 2013 miata. Loved the car but found it was consuming oil. So I figured oh well I’ll change the pcv valve no big deal. Pcv valve is wedged under the intake manifold. A 3 hour job for me versus 5 minutes on most cars. Plugs were fouled up, so I replaced those. Oil consumption issue now gone but due to oil consumption the valves are gummed up. Due to direct injection design I found the valves don’t have gas that naturally washes the buildup away. Whoever designed these engines is a moron.

Both my GDI cars generally see a service every three months because my other half and I live a distance from our workplaces so both cars do some considerable commuting. As yet, not real issues with either car and the kilometres are getting up there...One car at 160K...the other at nearly 90K...

Why can't you vent the gases to the outside air to prevent this? I know it is not allowed because of emissions, but is it possible?

Why hasnt anyone mentioned walnut blasting as a solution to build up

What do spark plugs have to do with the backs of the valves? Also,check the air in the spare!

The EGR makes it dirty the EGR system make sure your EGR is clean maybe there should be a some kind of a filter on the EGR

A guy can’t help but wonder what kind of toxic spew is coming out of the tailpipe when they spray that chemical in your engine.

Catch can. Don't be a cheap ass when buying one. You can expect to spend $150 and up for a quality can. Stay away from the cheap garbage on eBay. Do your research, and make sure the can has a mechanism to remove oil from the air that passes through it. And if you run one, get familiar with it and how often you should drain it.

You can get a mechanic to clean it or you can get a can of carburetor cleaner and fog it old school. Cleans everything downstream from the throttle plate. It can also clean and fix a stuck open EGR valve. Spray for a minute, let it soak for 10 minutes. Repeat 2 times. Fog.

Following your maintenance from the booklet won’t stop build up also. With turbo application different oil weight sometimes better than recommended. Since recommended is for fuel economy not engine protection.

Hey this is great advice for the 1990s. I don't think car dealers distribute maintenance schedules anymore. I have scoured the internet for a maintenance schedule for my Honda Accord and come up empty-handed. Everything just says do what the onboard computer tells you to do. And I doubt very much that it's going to tell you to change your plugs or get your injectors cleaned. I did find an online manual for my 2019 Honda Accord it is 500 pages long and has nothing in it about a maintenance schedule. A manual that is 500 pages long is basically about as good as no manual at all. This is all about just teaching you how to use a computer. It's more like the five volumes of operating instructions I got on my old Windows operating system in the early 1990s then a practical, serious guide to using these damn new cars and their stupid encrusted valves and their accompanying oil dilution problems which aren't even mentioned here.

110,000 miles on a DI engine with no problems. They're not meant to be driven by old grannies.

Gunk accumulates on the intake valve because the air/gas mixture leaks down to the crankcase. Is supposed to be pulled out by the pcv valve. But some of it stays on the crankcase and starts to condensing on the block walls. This dilutes the oil and make it easy to vaporize so the amount of oil/gas/air increases leaving more fuel on the crankcase and turning the oil into a big source of HC's and Gung for the direct injection engines. When the pcv pulls that super loaded of oil gas and divert it into the intake manifold this on it way to the combustion chamber touches the valve and turns into charcoal/gunk due to the intake valve high temperature. Maybe the solution. A catch can on the pcv side. And or increase compression radio so all the gas gets burn on the combustion chamber... O but wait that's bad for the environment

toyota d4s..port and direct..problem solved

What u really need to do is start early on using CRC GDI valve cleaner alone with BG FUEL additive.the valves r already gunked up bye 10,000 miles really bad,I'm a KIA tech and see it all the time because most of the engines r GDI .and by 30,000 miles you'll problem need a manual cleaning of the valves bye removing the intake,thats if u want good performance and idle like the vehicle was new.

Best solve, don’t buy a car has that type of engine.

This is why ford added port injection too. Best of both worlds

YOU ARE SO FAR OFF. USE AN AIR OIL/SEPERATOR OR CATCH CAN TO CATCH BLOW BY FROM THE PCV VALVE BEFORE IT'S INTRODUCED INTO THE INTAKE SYSTEM. EVERY OTHER OIL CHANGE USE A PRODUCT LIKE CRC GDI INTAKE VALVE AND TURBO CLEANER. YOU'LL NEVER HAVE TO WORRY ABOUT GUNK BUILDUP OR HAVING TO TAKE YOUR VEHICLE TO THE DEALER FOR A WALNUT SHELL BLAST/VALVE CLEANING

Throw more money at the problem! Amazing advice.

Get rid of EGR and install a catch can is what you need to prevent valve gunk in a GDI engine.

I have a catch can on both my new vehicles and only use a top tier fuel

Now if these tips actually help. This guy is clueless about lntake valve carbon buildup.

Forgot to mention an oil catch can to help prevent deposits.

None of those solve the problem or even alleviate the main problem of the GDI engine. You want to know how the intake valve gets that way? It Positive Crankcase Ventilation. Fine misted oil is getting on the backside of the valve, and combine that with Exhaust Gas Recirculation, and you are just driving on borrowed time. There is really no significance in power by putting the injector directly into the combustion chamber. The reason for it is emissions which sacrifices reliability. My advice, ALWAYS use premium fuel. Always use Top Quality oil that has a Soot Control Additive. Thats all you can do. The rest is pointless. Its the design of the engine that causes the problem.

Buy a car with a dual injection engine. Been in Lexus and Toyotas since 2006

Here's a thought : the car manufacturers are well aware of this problem,so how come they don't install catch cans at the factory and save the consumers big headaches down the road ?

$1300 later . Thanks vw for stupid design.

Catch Cans can help reduce oil and water vapor form mixing with the stuff from the EGR system in the intake system use two catch cans in series and use 10w 30 motor oil will help to.

All these tips won't prevent carbon built up. The most effective way to prevent that is to install a mechanical filtration oil catch can so no oil vapor goes back inside the intake system which is the main and only reason for carbon building up. Thabks

Have you heard of routine intake cleaning? that's all you need... once a year or every 6 months if you drive really hard or do a lot of short trips. Catch cans don't work most of the time, that's why they do not come installed from factory.

Every direct injection engine, especially if modified, must have an air/oil separator installed in to catch the blowby that coats the intake valves. IAG makes one for $400

Do you recommend some sort of catch can to trap oil and water vapours from the crankcase ventilation system before it's recirculated back to the intake? Or are these mostly for turbo engines?

depois do procedimento é necessário fazer a troca de oléo?

The best way to keep your valves from developing any “valve gunk” is to drive a car without GDI. Keep driving your regular MPI vehicle. The fuel economy is not any different from a GDI to MPI and the repair costs are a lot higher with an GDI. Just ask anyone who has had to replace their high pressure fuel pump. GDI is trash.

love how in the video the person getting gas grabbed regular... and this is why his fuel injectors were clogged early . Chuckled pretty good lol

With direct injection you will be changing your engine before you need to change your spark plugs

the latest cars with direct injection (lexus, corvette etc) have port injection as well, this keeps the valve clean better, than a catch can

I've found that the pest way to prevent carbon build up on the vlvs is to not drive it like a sissy, these engines love to be reved

I just bought a new Mazda 6, just found out Skyactive engine has direct injection...now I have second thoughts...

This video could be shortened to about 1 minute...intake cleaning via chemical cleaning. The rest is mostly not true if at all.

What about the little bit of oil on the valve that get past the valve stem seals? No premium fuel, spark plug change or oil will help clean your valves...

Wouldn't a catch can make more sense than everything else? I admit to being completely ignorant on this topic but if the fuel never hit the back of the valves then the souce of the gunk needs to be addressed. At leaast I think...

As you can see by the other comments none of the suggestions u mentioned would keep a DI engine intake valves or head clean, They are good things to do to a car but not tho keep the intake clean