I'm on board with all of above, with one exception. Having a "Catch Can" or oil air separator is better than not having one. As long as, as you mention, the owner of the car is diligent and capable of periodically emptying it.I can say from experience over 3 different cars now that used GDI (my last 3 vehicles, 2006 mazdaspeed3, 2011 hyundai sonata 2.0T and last 2013 Genesis coupe 3.0 track) you will very likely NOT have any issues with the GDI.
This has been a combined amount of 300,000 + miles I have driven a GDI engine, 2 turbocharged, 1 naturally aspirated, I have had ZERO engine issues of any sort. Specifically I know the 2.0 Theta engine well since it was in my sonata. Anyone questioning this, know full well if you are a responsible driver, and maintain your vehicle properly, using reliable gasoline sources there will not be any problems. A bottle of Techron run through it every 3 or 4 months wouldn't hurt, but probably not needed either.
Now if you drive short distances, and never let it warm up I can't speak for that, but it causes problems on regular fuel injected engines too, so you know what to expect there.
If you don't mind spending just a little more on the oil, I highly recommend Pennzoil platinum, as it will keep your engine squeaky clean on the inside. All three of my previous vehicles ran that exclusively, and they were clean like new under the valves after my 100,000 miles of use.
In regards to catch cans, they are not really needed, and a lot of hype to be honest. Not to mention, you will need to be getting under the hood and emptying them on a regular basis or it will spill everywhere and make a mess.
I agree with this 100% and have used CRC intake valve and turbo and plan to install a catch can. I mean let's face it, doing all you can to keep blow by oil from passing over the valves regardless of injection method, just makes good sense.Theres no way of getting around positive crankcase fumes needing to be reintroduced into the intake, toyota and Ford have designed a dual injection system where they combined port injection with direct injection and that gets rid of the problem but now you have more parts that can fail.
but you can install a catch can, and every 30K run sea foam into the throttle body and burn off any carbon build up, also valvoline just came out with an oil that aids in eliminating carbon build up in intake valves called modern engine oil.
I personally like the catch can idea and cleaning the valves with sea foam every 30k, that sould solve that issue altogether.
Seriously? The claim is made here that air turbulence in the cylinder is SO extreme that atomized fuel (misted into the cylinder) is blown up past the intake valves, past the incoming blast of air, to dampen the back side of the intake valves with a little fuel and thus clean away carbon deposits? I refuse to believe without evidence that anything of the sort happens at much above idle but it's still hard to believe that such magic could happen even in an idling engine. What you describe has little to do with "injecting fuel in such a way" but rather with air swirl in the combustion chamber at idle being SO extreme that air/fuel from the cylinder is carried across the back of the slightly open intake valves. Moreover, all this magic in defiance of physics happens without anything unusual-looking in the intake, and without any patents or any advertising claims that you can site. We should just take your word for it? Wow.They have designed the engine to inject fuel in such a way that it does in fact get some onto the backside of the valves so major buildup doesn't get a chance to accumulate. This is a common technique on the more recent engine designs and is used by several different companies, This is what has been determined to work best to reduce the deposits. This method is done by injecting fuel during the cycle where the valve is in the open position so that a mist of fuel / air does get exposed to the valves while they are open. While not as good as fuel coming down into the chamber through the valve, the exposure is enough to resolve the problem.
The subject of the thread is about carbon build-up on the back of the intake valves - not on top of the cylinders.I've noticed carbon build up on tops of my cylinders.
What made you come to that conclusion? Did your oil level go up? Can you smell gasoline in the oil? You say that the oil seems diluted with fuel. The only sure way to determine the presence and concentration of fuel in the oil is to have an oil analysis done.I also noticed the oil seems diluted with fuel after an oil change at about 1,500-2,000 miles.
First off, the reason for this carbon build-up in a KIA GDi engine is that the back of the intake valves are not washed with fuel (since the fuel is sprayed directly in the combustion chambers). Therefore, adding a fuel system cleaner to the gas tank - irregardless of the potency - is going to do very little in cleaning this carbon.I'm gonna start running a potent fuel additive concoction (like 6 bottles of techron in a half tank of premium ethonal free unleaded) right before every oil change to see if this cleans up the carbon.
A 10W-40 oil (or any 40 weight oil) is thicker than needed (even for where you live) and will not keep the oil "thicker, longer". And also will do nothing to mitigate your carbon issue. Just stick to a high quality 5W-30 oil (preferably full synthetic) with a SN Plus rating.I'm also gonna do oil changes with half 10w-30 to half 15w-40 on oil changes, or perhaps full 10w-40, to help keep the oil thicker, longer.
Scotty Kilmer's opinions are highly overrated.Kilmer says GDI is not good in most car designs.
Yes, I understand what you're saying (and thank's for clarifying). Obviously a 40 weight oil will always be "thicker" than a 30 weight oil (it's viscosity at operating temps will be higher). It will be thicker when you pour it in your engine, and, all things being equal, it will still be thicker when you drain it. That goes without saying....running thicker oils stay thicker when mixed with fuel or run for longer times.