Oil type, no big difference | GDI carbon

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Originally Posted By: Nick1994
Everyone talks about carbon deposits with GDI, but how do they know how much this happens? Where can you see this? Sounds like a lot of speculation from people who haven't torn their engine apart to check whether it even happens or not.
*Only way to tell is with a bore scope !
 
Originally Posted By: Silverado12
Kia/Hyundai is bottom of the line anyways so I would expect problems. I would move towards something known for better reliability if you don't have mechanical skills to fix your issues.
*Here is my plan to deal with my bottom of the line Hyundai GDI engine : 1) Use Top Tier Fuel 2 ) Use low NOACK D1 Gen 2 synthetic oil 3)stay with 5K mile OCI's max 4) Use fuel system cleaner before every oil change 5)Use CRC Intake Valve Cleaner every 15K miles 6) Lastly , change spark plugs slightly early ... I have 16K miles on my Sonata GDI engine now ... If I still end up with a carbon build up issue after 40K miles - then I give up (lol !)
 
Compared to NOACk "oil thickening?" The crank case os full of oil mist and blow by products making any evaporation of the oil
in consequential.
 
Originally Posted By: CT8
Compared to NOACk "oil thickening?" The crank case os full of oil mist and blow by products making any evaporation of the oil
in consequential.


Not true. Oil in a gaseous state is far more likely to stick and result in a deposit than in liquid form (mist).
 
That’s not a fair comment or statement. Hyundai and Kia come a long way in short period of time and make a good vehicle. My first car was a 03 Tiburon GT V6 and was all around a great car same with my fathers 03 Sonata and 07 Santa Fe. Many Direct injection engines are having the carbon issue even the German automakers.
 
Originally Posted By: Silverado12
Kia/Hyundai is bottom of the line anyways so I would expect problems. I would move towards something known for better reliability if you don't have mechanical skills to fix your issues.


You are just un/misinformed.
 
Originally Posted By: PimTac
I have to believe that driving patterns and possibly fuel choice matter here. A typical GDI vehicle that sees 80% of its trips less than a few miles running on cheap generic 87 octane gasoline would seem to me one of those mentioned with buildup at 30k. There are a lot of these situations out there. Many drivers who own a GDI don’t even know what it means.


That and lack of timely OCIs or at best, following the OLM which is incorrect.
 
Does the length of OCI's really have any affect of the carbon buildup on the intake valves?

or is dilution a concern?
 
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Originally Posted By: mx5miata
Does the length of OCI's really have any affect of the carbon buildup on the intake valves?

or is dilution a concern?


My understanding is that fuel dilution leads to a drop in the flash point of the oil, leading to more burn off, leading to more oil vapor passing thru the intake.....
 
My GDI Kia is going on 85K. No issues whatsoever. I will say that I change the oil every 5K and my driving is probably 85% highway. One way to work is 25 highway miles. The other 10 is usually a lot of traffic though. That may be the biggest part of imy success is I get the engine good and hot every day. Other than factory fill and the first oil change (semi-Synthetic) all oil changes have been whatever full synthetic I can get cheap. I use Techron every oil change and usually use top tier fuel. Usually I use 5W-20 in winter and 5W-30 in summer. So I am happy with my “bottom of the line” KIA.
 
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Oil is not the main cause of DI carbon build up, EGR is. The quality of fuel you're using will affect how much soot is in the EGR, it has a much bigger impact than oil choice.
 
Originally Posted By: Urshurak776
My GDI Kia is going on 85K. No issues whatsoever. I will say that I change the oil every 5K and my driving is probably 85% highway. One way to work is 25 highway miles. The other 10 is usually a lot of traffic though. That may be the biggest part of imy success is I get the engine good and hot every day. Other than factory fill and the first oil change (semi-Synthetic) all oil changes have been whatever full synthetic I can get cheap. I use Techron every oil change and usually use top tier fuel. Usually I use 5W-20 in winter and 5W-30 in summer. So I am happy with my “bottom of the line” KIA.


I'm curious what does your oil look like at the end of your oil changes? My girlfriend does 3k mile oil changes and her oil is tar black even immediately after an oil change. 60k miles on her 13 Sonata. Smells like gas too
 
Originally Posted By: caprice_2nv
Originally Posted By: Urshurak776
My GDI Kia is going on 85K. No issues whatsoever. I will say that I change the oil every 5K and my driving is probably 85% highway. One way to work is 25 highway miles. The other 10 is usually a lot of traffic though. That may be the biggest part of imy success is I get the engine good and hot every day. Other than factory fill and the first oil change (semi-Synthetic) all oil changes have been whatever full synthetic I can get cheap. I use Techron every oil change and usually use top tier fuel. Usually I use 5W-20 in winter and 5W-30 in summer. So I am happy with my “bottom of the line” KIA.


I'm curious what does your oil look like at the end of your oil changes? My girlfriend does 3k mile oil changes and her oil is tar black even immediately after an oil change. 60k miles on her 13 Sonata. Smells like gas too


Almost all modern GDI engines suffer from this, caused by low tension piston rings all in pursuit of MPG gains. It's tar black because of all the soot generated by high combustion temps like in a diesel.
 
i run a qt. of 15-40 rotella in every oil change. treat it like a worn engine.
 
Originally Posted By: 08z06
i run a qt. of 15-40 rotella in every oil change. treat it like a worn engine.


You run a qt of 15w40 in what?
 
Originally Posted By: caprice_2nv
Originally Posted By: Urshurak776
My GDI Kia is going on 85K. No issues whatsoever. I will say that I change the oil every 5K and my driving is probably 85% highway. One way to work is 25 highway miles. The other 10 is usually a lot of traffic though. That may be the biggest part of imy success is I get the engine good and hot every day. Other than factory fill and the first oil change (semi-Synthetic) all oil changes have been whatever full synthetic I can get cheap. I use Techron every oil change and usually use top tier fuel. Usually I use 5W-20 in winter and 5W-30 in summer. So I am happy with my “bottom of the line” KIA.


I'm curious what does your oil look like at the end of your oil changes? My girlfriend does 3k mile oil changes and her oil is tar black even immediately after an oil change. 60k miles on her 13 Sonata. Smells like gas too


I don't think it looks bad at all. The paper towel test looks no worse then the oil from my non GDI Hyundai. My engine seems to be very clean. I cut my oil filters also. No issues. I really think Hyundai/Kia have good GDI engines if maintenance is done properly.
 
I have 130 000 km on my 2011 Kia Optima. I installed a catch can in January 2012 and have had no problems to date. I change the oil every 10 000 km using 5W20 in the winter and 5W30 in the summer. Most reliable car I have ever owned. I also have a 2005 Civic.
 
My best friend that still works in the oil change bay I used to, says pretty well all the Hyundai's and kia GDI engines he sees have black oil before and usually even after he changes it. Texted me about one the other day that runs full synthetic and was only at about 4500 miles and the oil was black like a diesel before and after the change. They've also seen 2 personally come in with the famous failed rod bearings that the NHTSA safety recall is all about. I'm sure the dealership sees a lot more than an independent garage since most people should have gotten their recall notice by now.

I'm just concerned about whether the black as tar oil is just because of the direct injection or if her engine is going to fail like so many others have.

The freshly changed oil in her car looks much worse than the dirty oil with 5k miles I drained out of my 83 Caprice which is a carbureted engine and probably has some fuel dilution issues of it's own.
 
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Originally Posted By: Nick1994
Everyone talks about carbon deposits with GDI, but how do they know how much this happens? Where can you see this? Sounds like a lot of speculation from people who haven't torn their engine apart to check whether it even happens or not.


This!

I also got a 2.4 GDI Santa Fe with 110k miles. Engine and transmission perform the same as when I got it. Regular maintenance and you'll be ok.
 
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Yeah, but you're unique....just like everybody else
smile.gif


Basic knowledge and experience might tell you that you can't make blanket statements about GDI-related issues. Does a Hyundai Gamma II with 80K miles on it have the same basic carbon involvement or susceptibility issues as an Eco Boost with 100K miles...and if neither experience driveability issues or hesitation, mpg loss, etc. in that time, does that mean it's right around the corner?? I'm sure it does on here, but I'd be much more interested in the empirical reality circa 2018 and the individual, well-maintained engines.
 
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