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Need help with carbon build up

22K views 21 replies 14 participants last post by  sbr711 
#1 ·
My 2014 Santa Fe cant have the engine light cleared unless the engine is taken apart and cleaned. The warranty and dealer will not cover this so I suspect my 2016 Accent with a GDI engine will have this problem as well. Until I can get rid of these vehicles, can I run non ethanol fuel to decrease carbon build up? I wont be able to afford having the engines cleaned every few thousand miles. NYS will not pass inspections with the engine light on. Thanks for any input.
 
#3 ·
What is the DTC that was recovered..

Sound like a bunch of Horse Hockie to me...
 
#4 ·
They cleared it 3 times and it comes back on shortly after I pull out of the dealership. PO275. They had me run 2 cans of cleaner at 30.00 a can. It didn't work. So now they want me to run 6 more cans. If that doesn't work then they have to pull the engine apart and clean the valves, and piston rings.
 
#7 ·
Seen that definition on Veloster in past..

No "DRIVES" PROFILE ENTRY,,, so I dont know if 2.4L or 3.3L,, not called out in text of post either

Contribution/balance ended up with replacing injector,, WARRANTY only pay for 1 injector..
 
#8 ·
Nearly every Direct Injected engine has this problem. The fuel is injected directly into the combustion chamber. As a result, the fuel isnt able to clean the back of the valves causing carbon build-up.
You will most likely need to have it blasted with walnut shells. This is the most effective and cost efficient way. Still expensive. BMW's regularly have this done at a cost of$3500. At least at my shop.
 
#9 ·
I was impressed with the "CRC intake valve cleaners". They did cost me just 15$ CAD (so it should be less than 10$ US) per dose. There are clips on the internet where to spray them.
The procedure I used is what they recommend:
1. warm up engine
2. 30 sec of spray bursts into the air intake (past MAP, past air filter) - while somebody keeps the engine at 1500-2000 rpm
3. when the spray bottle is done - 3-4 times of revving to 3500 rpm
4. let it settle on idle (3-5 min)
5. turn engine off and let it rest for 1h
6. take it for a spin on highway - 10 min at least, high rev. What I did is set up the cruise control to 120 kmph/75 miles - then I switch to shiftronic (manual gear) and drop the gear (all the way to 3rd, where I had 5200 rpm/min)
That should do it. In my case, I can vouch that the mileage improved about 10-15% and idle is smooth like a baby's bottom :))
Mind you that large carbon deposits can dislodge and mess up with the catalyser.
 
#10 ·
No amount of any of cleaner poured in the gas tank will clean the valves in a direct injection motor since the gas does not come in contact with the back of the valves.

I would not think a cleaning is needed until near 100,000 miles. I can't image a company making a motor that requires such an expensive process before that mileage.

I have read in other forums concerning direct injection that an Italian tune up helps occasionally. I do that with our Escape. We'll see if it has any positive results in the long run.
 
#14 ·
The problem is the vehicle is only three years old and will not pass inspection. I cant see spending $3500 for sandblasting every three years or less. I'm sorry I just bought the Accent too. These vehicles have to go. People need to be aware of this problem before they purchase a new Hyundai.
 
#16 ·
Its not only Hyundai but any GDI engine out there. Nissan and Jeep and maybe Toyota are the only manufactures out there that don't exclusively use GDI. Beware of smoke and mirror fixes. The only known method to clean carbon is some sore of manual cleaning or media blasting technique. Good luck.
 
#18 ·
I've read Toyota (certain models) utilize MFI and GDI together. As much as it's extra parts and tuning, it seems like a good solution, until gas becomes pure and leaves no byproducts (ain't gonna happen).

BMW has a valve decarb service. Search BMW walnut shell blasting.

None of this this is especially helpful to you though. Try another dealer if one is close enough.
 
#20 ·
The moment I read those "Carbon Build-Up" from the intake valves of the the GDI Engines, I immediately purchased an OIL CATCH CAN and installed it last year.

My 2012 Sonata is now on its 121k KMS and I plan to do an intake valve cleaner thing once we get a warmer weather here in Ottawa, Ontario Canada. I found an easy access where to squirt the CRC spray near the valves. The access is where the PCV hose connects to the intake manifold.

Let's keep our fingers crossed.
 
#21 ·
The thread has gotten a bit off-topic from helping the OP.

OP - if your fuel injectors are clogged, running cans of cleaner through the fuel tank MIGHT help.

If your valves have carbon build-up, running cans of cleaner through the fuel tank is a waste of money, and I would be mad that the dealer svc dept didn't know enough to even suggest it might help.

The CRC service might help and is worth a try. There are various opinions on the forum on it and I don't want to get into a war here. Some members think it is a waste of money, and some members think it is essential unless it is a lease car or you will be trading the car every two years or so.

My personal observations from reading some of the threads:

- The members that think it is beneficial (principally @Deadrx7) recommend it every 25K miles.
- @Deadrx7 also said it is more of a preventative - i.e. using it every 25K miles will help prevent the problem, using it multiple times after you HAVE a problem is less likely to help - but is cheaper than having the engine torn down and fixed, so is worth a shot.
- Removing the intake manifold and cleaning the valvetrain is expensive, I don't know exact pricing, but I would guess $1500 on the low side, and $3500 on the high side.
- There are a LOT of GDI cars (Hyundai and other makes) with more than 75K or 100K miles that have never had an induction service or run a catch can and still run fine, so you can't really say it's an inherent issue or something that REQUIRES induction cleaning.
- The members that think it is a waste of money (principally @Artdm and @sbr711) usually point out that it is never mentioned in the suggested service in the owners manual. I'm not sure this is a great argument. If the problem usually doesn't become an issue until 75K or more miles and usually doesn't cause a drivability issue until after 100K miles when the warranty has expired, I'm not sure the manufacturer cares or would recommend it.
- There are a lot of new and different things (CVT, DCT, GDI, no-dipstick transmissions, longer OCI's, turbos, ECO mode, auto start/stop at traffic lights, no maintenance (can't maintenance) batteries) which are marketed and sold as improvements and really are more like drawbacks.

- My personal opinion is that I will probably see how the car is running at 50K miles and CONSIDER (but not necessarily DO) a DIY CRC cleaning at that mileage.
 
#22 ·
I'm out of here until OP posts up the engine that this 0275 was recovered from.. and edits his DRIVES profile to reflect 2014 Santa Fe along with which engine..
 
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