Oil for a Direct Injection engine?

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Hi everybody.

I have a new Hyundai direct injection (GDI) engine and am curious about oil as it relates to this type of engine.

Does the type of oil (synthetic vs conventional) have any effect on the amount of soot produced by the exhaust on a direct injection engine? Also, does the oil type (again, synthetic vs conventional) effect the rate of carbon buildup on the intake valves on this engine type?

Thanks for your insights on this subject.
 
Direct injection seems to dilute the oil with fuel pretty quickly so it's prudent to follow the manufacturers recommendations.
As far as soot I dont think it's an issue, and since the fuel is injected directly into the cylinder the intake valves never come in contact with any fuel,and the exhaust valves would behave similar to any other engine.
 
No specific oil recommendation, but Hyundai is now calling for a fuel system cleaner at every service interval.
 
I have some experience with this. The only real answer is as good of a synthetic as your wallet can afford and short change intervals. It sounds like you have a normally aspirated version, yes? So it's not really bad at 7500 miles. Hyundai is telling you on a turbo that it beats up the oil quick by a max of 4800 miles. Even quite good oils are toast at 4800 in my car. It qualifies as severe which Hyundai says 3K miles, but even I can't do much of that, lol! I've only gotten to 4600 before it grosses me out to see how black it is and how fragrant with fuel it is. They back door the synthetic requirement by saying for added performance use 5w40. There is some evidence that low saps and low volatility are ways to better your talking points.
 
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I got a 2011 Hyundai Elantra and use Motorcraft 5w-20, OEM filter, and change every 5k miles (just cause it's easier for me to remember). Oil never smells like gas when it comes out. We have had no issues with the car and got 32k on it now...:)
 
Originally Posted By: rossn2
I got a 2011 Hyundai Elantra and use Motorcraft 5w-20, OEM filter, and change every 5k miles (just cause it's easier for me to remember). Oil never smells like gas when it comes out. We have had no issues with the car and got 32k on it now...:)


That isn't a GDI engine.
 
I drive a 2007 Mazda CX7 DI turbo engine vehicle and change oil at 6,000 mile intervals. I have 3 UOAs over the 60,000+ miles driven that demonstrate that even with ~ 1% fuel in the oil, that wear levels are very good. I also had concerns about intake valve cleaning but, to date I have has no issues. I think modern DI engines have much less problems with intake valve issues and probably fuel dilution issues also. Sometimes we just need to find something to worry about when there is nother there? Ed
 
Thanks for your replies. The 1.6L naturally-aspirated GDI engine is a pretty impressive effort by Hyundai.

It's not really a big deal overall, but the soot accumulates very quickly and it's tough to keep the rear bumper clean. Having white paint doesn't help, either. I wish direct injection engines weren't set to run so rich, but I guess that's the nature of the technology. I recently owned a Mazdaspeed 3 that also ran rich; add the turbo to the mix and that car was very tough on oil.

Am I correct in assuming that synthetic oil is less likely to crud-up (sorry for being so technical) the intake valves on a direct injection engine? I know this has been asked a million times, but I assume it's okay to switch to synthetic at the first oil change? I'm planning on doing the first change at 1,000 miles or so.
 
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I did a UOA on my '11 Sonata with the 2.4 DI engine, M1 5w-30 with 5,500 miles on the oil. Came back with no trace of fuel. That was the first oil after the FF came out. I have since been using M1 5W-30 EP and now go 7.5K. Although I've not done another UOA, I do my own oil changes and have never detected any odor of fuel, even when some used oil has gotten on my hands.

I don't use a fuel system cleaner, but I do use a Top Tier fuel, which my owner's manual mentions. I think that's what Hyundai recommends: Top Tier fuel or the additive.
 
Manufacturers may have a much better handle on the intake valve deposit issue now, but to be on the safe side I'd suggest choosing an oil with low volatility to reduce the amount of offending vapors sucked into the PCV system.

Noack volatility seems to be pretty much in the same range for oils generally available in the US with 2 exceptions: Amsoil Signature Series and Pennzoil Ultra. Both of these are fine oils and have substantially lower volatility than other choices, but Ultra is cheaper and likely available at your local Wal-Mart

I have a 2012 Ford Focus with a DI engine and have chosen Ultra. 13,000 miles and no oil-related failures yet, so it must be working!
 
I'm certainly hoping that manufacturers are getting better at dealing with valve deposit issues. There's some scary stuff out there regarding Audi buildup issues, etc (although I assume this is getting to be fairly old now).

I've used the Hyundai/Kia recommended Techron additive recently on another 1.6L GDI that I have (my wife's 1.6L GDI is six months old).

I'm thinking that if the Techron every six months + nice synthetic @ 3K intervals doesn't keep these engines clean, there's something wrong.

I'll look into the Ultra since Pennzoil seems to be pushing the cleaning aspect of their oils more than their competitors. It certainly looks like changing to synthetic can be done at any time with no need to accumulate miles before the switch - if this assumption is wrong please let me know!

Thanks for your help on this, guys.
 
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Exhaust will be the same - port or DI injection.
IF the DI system is programmed richer, you may get fuel dilution and maybe some more exhaust deposits. May USA cars are indeed unexplicably richer than Euoropean models, esp with turbos.

Intake valves will be dirtier with DI systems. It is their biggest problem as there is no fuel wash to clean them. Deposits come from oil down the valves, PCV system gunk, an overlap breathing. They intake valves also run hotter and any deposits are more apt to stay.
 
I agree regarding intake vs exhaust cleanliness on direct injection engines. I also scratch my head regarding the rich mixture on DI engines, but there must be some logic to it (I assume for durability).

I've even considered doing a yearly SeaFoam through the vacuum line... but this is for future obsessing.
 
Originally Posted By: mechtech2
Deposits come from oil down the valves, PCV system gunk, an overlap breathing. They intake valves also run hotter and any deposits are more apt to stay.


I'd love to hear car manufacturers tell us why we don't need to worry about intake valves with DI. It sure worries me as you suggest.

Toyota's direct injection makes sense because it uses direct and port injection, and the little bit of port injection cleans the intake valves. That makes so much sense to me.

I read on another forum that at one time Mercedes had researched having a canister of Techron in the engine bay and it would slowly be released onto the intake valves, but this design never came to be.

I sure hope the manufacturers haven't simply found out that the deposits for the first 100,000 miles or few years, won't stop the car from running and therefore, don't worry about it. I like to keep a car a long time.

Adding techron yourself to gasoline on DI engine won't help because with the direct injection, you aren't reaching where the deposits occur, just like the gasoline isn't reaching there causing the problem.

DI is here to stay, and I would still buy a car with DI. I just wonder how it has been solved in cars outside of Toyota's unique port and direct injection.
 
I think you may be on the right track with manufacturers just ignoring a long-term problem. I guess there's just a bit more maintenance to direct injection ownership (without any port injection), if you want to keep the engine clean/working to spec. I also agree that Toyota's idea holds up to common sense - if it works long-term maybe this setup will become a standard.

I'm already accepting the idea more maintenance since I don't mind a little tinkering. Techron every six months or so for the injectors, coupled with (maybe) SeaFoam every year for the intake valves should be super-safe.

I'm still dubious about SeaFoam since I've never used it, but I'm sure there are loads of threads on this subject. More fun reading...
 
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