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Cold startup sputter/shutter

Anyone can pump 93/premium into any car, and it should work fine. But, if the engine is designed to run on regular, you're just emptying your wallet faster. The only reason I know of to put in higher than recommended is if you have knocking (pre-detonation).

Higher the octane, the more resistance the gas has to combustion. That's why high compression engines require higher octane. Higher pressure needs more resistance to combustion so the pressure can build before detonation. In general, higher pressure results is more engine power. But all the components in the engine need to be able to handle the higher pressure.

An engine that isn't designed for premium isn't magically going to create more pressure/power when premium is added.
 
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Do you burn regular unleaded or super? It sounds like possible bad gas.

I've used regular unleaded since the car was new and never had any issues. The reason I discount bad gas this time is the tank was just over half full so it had already burned much of the tank off without any symptoms.
 
My 2013 3.8 V6 is doing the same thing as the OP. Sputtering for a few seconds while backing out of the garage after sitting all night. Anyone find an answer for this issue?
 
My 2013 3.8 V6 is doing the same thing as the OP. Sputtering for a few seconds while backing out of the garage after sitting all night. Anyone find an answer for this issue?

Unfortunately no or not that I have found. Either we have cars with a rare issues or most owners don't pay close enough attention. I have changed the oil, used the recommended filter, tried every Shell gas octane and the issue is still there. Honestly I don't keep cars long enough to look into it any further. While the Genesis is a nice car (love the interior) the laziness of the throttle response has made me not like the car as much as my past vehicles.
 
I too have been startup issue, rough idle for quite some time, dealer blames bad fuel. I think the GDI engine has more issues then they wish to disclose. Dealer has been putting 5-20w oil in even though manual says 5-30w or 10-30w for my 2012 3.8l sedan. Dealers do not service many Genesis and I think they get mixed up on what they recommend.
 
I have a 2011 3.8 and it makes a terrible sound after sitting all night. (cold start). It only does it after sitting overnight. Sounds normal the rest of the time when I start it up.:grouphug: lets put our heads together...

49,200 miles -fresh oil change and it still does it.
 
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Mine has been to the dealer twice now. First time they noticed #3 cylinder miss firing so they replaced the coil pack. Took it home and it did the same thing, sputtering and bucking while in gear for the first 20-30 sec after sitting for around 8 hours. It does it every morning and after my wife starts it up when leaving work after sitting all day. Second visit we dropped it the night before and had them pull it into the tech bay so they could hook it up right from the start after sitting all night to see what is going on. Still same thing #3 miss firing. They changed spark plugs, moved spark plugs from other cylinders, moved coil packs. Then they said there was a lot of carbon build up in the throttle body and intake, so the cleaned it all up. Took it home and still have the same problem. Going to try to get it back in there again, but I don't think they know what else to try.
 
Mine has been to the dealer twice now. First time they noticed #3 cylinder miss firing so they replaced the coil pack. Took it home and it did the same thing, sputtering and bucking while in gear for the first 20-30 sec after sitting for around 8 hours. It does it every morning and after my wife starts it up when leaving work after sitting all day. Second visit we dropped it the night before and had them pull it into the tech bay so they could hook it up right from the start after sitting all night to see what is going on. Still same thing #3 miss firing. They changed spark plugs, moved spark plugs from other cylinders, moved coil packs. Then they said there was a lot of carbon build up in the throttle body and intake, so the cleaned it all up. Took it home and still have the same problem. Going to try to get it back in there again, but I don't think they know what else to try.

Most likely if the TB / intake are covered with carbon you need to take your car back to the dealer and tell them to perform a Induction service. The later model GDI engines build up carbon on the valves and that will cause shuttering with a loss of performance. GDI engines are prone to carbon build up because the fuel is sprayed into the cylinder not washing the carbon from the valves. If the carbon build up is really bad they may have to perform the induction service twice. The service should be performed every 30K and you need to blow it out once in a while.
 
Sounds to me like old lady car issues, AKA engine build up.

Floor it once and a while, get parts moving fast and hard, don't let carbon and sludge build up even happen.

If you get mud in the treads of your car and putt around all the time, that mud will stay caked in there. If you give it hell once you get on the open road, all that mud will come flying off and your tires will look good as new again.

Same principle


Have your mechanic take a look at your catalytic converter too. If carbon bits did build up and then broke off they would get caught in the CC and plug it up. That would cause it to run like a bum too.
 
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My Hyundai Dealer is adding more service items that were never suggested in the original service manual. It looks like they are finding more problems with GDI Engines. Some of these services have been done on my car and I still have a rough idle on start-up.
1) Added Fuel treatment at every service instead of every 12000km
2) Perform Fuel/Air Induction Service
3) Install Premium Oil Conditioner
4) Perform Minor Transmission Service
5) Perform Minor Fuel System Service
6) Perform Engine Restoration Service
7) Perform Minor Coolant Service
8) Perform Battery Service Clean and Install Anti-Corrosion Pads

This is what my dealer is offering as ungraded service levels which I have never seen before. Now the have Basic, Premium and Complete service packages. it seem they are trying to design flaws, warranty claims and make the owner think it is just regular service.
 
Blowing it out is not the problem. I give it hell all the time. No old lady driving here. I think it is computer related because it happens the same every time. Low idle and sputter for 20 seconds, then all the sudden something switches on and idle goes up and smooths out.
 
A little follow up on my sputter issue. A month or so ago my check engine light came on and I took it to my dealer. They checked it and said was saying something is wrong with the catalytic converter. They reset it and said drive it some more and come back if comes on again. Two days later I'm back with same code so they replaced the cat, and I was hoping that might have something to do with the sputter. But no, still there. Two weeks ago I dropped the car off for oil change and have them check the sputter again. This time they just changed out all the injectors except for #3 since it was done not to long ago. A little over two weeks now and no more sputter. YEAH!!! Hope this last now.
 
I gave up on my car traded it in on a Toyota Avalon, got tried of dealer not being able to fix this and other problems. Car seems to complicated for them. Still miss my Genesis, but not the problems.:)
 
A little follow up on my sputter issue. A month or so ago my check engine light came on and I took it to my dealer. They checked it and said was saying something is wrong with the catalytic converter. They reset it and said drive it some more and come back if comes on again. Two days later I'm back with same code so they replaced the cat, and I was hoping that might have something to do with the sputter. But no, still there. Two weeks ago I dropped the car off for oil change and have them check the sputter again. This time they just changed out all the injectors except for #3 since it was done not to long ago. A little over two weeks now and no more sputter. YEAH!!! Hope this last now.
How long did the fix last?
 
A little follow up on my sputter issue. A month or so ago my check engine light came on and I took it to my dealer. They checked it and said was saying something is wrong with the catalytic converter. They reset it and said drive it some more and come back if comes on again. Two days later I'm back with same code so they replaced the cat, and I was hoping that might have something to do with the sputter. But no, still there. Two weeks ago I dropped the car off for oil change and have them check the sputter again. This time they just changed out all the injectors except for #3 since it was done not to long ago. A little over two weeks now and no more sputter. YEAH!!! Hope this last now.
Also how many miles when you had it done?
 
I have the same problem on 3.8 I suspected fuel related. Will try a red neck injector cleaning and see what happens.
Going to plug my fuel pressure gauge into it and see what its doing at start up.
 
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Unfortunately no or not that I have found. Either we have cars with a rare issues or most owners don't pay close enough attention. I have changed the oil, used the recommended filter, tried every Shell gas octane and the issue is still there. Honestly I don't keep cars long enough to look into it any further. While the Genesis is a nice car (love the interior) the laziness of the throttle response has made me not like the car as much as my past vehicles.
The shame part is these cars are Beast in sheep clothing. I pulled my ESC fuse yesterday and went for a short ride car ran like a rapped app.
 
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