Solutions for DI Engines?

[chubbs1]

I know there have been posts on this before. The best alternatives I had seen was don't buy them until the bugs were worked out. I Just got a 2011 Sonata GLS 2.4 GDI.

What are some ways we can keep these injectors clean?

Do you use fuel system cleaner? Do you think using MMO in the tank and the Crank Case?

Or is this a hopeless situation? Lets put some BITOG ideas together!

 

[Steve S]

I don't think the injectors are a problem. MMO or cleaner in the fuel will not help . Let the dealer take care of the problems under warranty.

 

[justinf89]

I thought it was the valves you had to worry about, not the injectors?

 

[poiuy223]

I loaded up on fuel system cleaners. A bottle every 5000mi oci.

 

[chubbs1]

Originally Posted By: Steve S
I don't think the injectors are a problem. MMO or cleaner in the fuel will not help . Let the dealer take care of the problems under warranty.


You do have a good point there.

 

[2002 Maxima SE]

Originally Posted By: poiuy223
I loaded up on fuel system cleaners. A bottle every 5000mi oci.


That will not help a DI engine. The injectors are in the cylinder, which does not allow the fuel/cleaners to wash over the valves.

DIYers are using cleaners through the brake booster vacuum hose in order to get cleaners to wash over the valves.

 

[JHZR2]

Redline si-1 supposedly survives the combustion process and can help keep DI clean.

 

[Gene K]

Originally Posted By: JHZR2
Redline si-1 supposedly survives the combustion process and can help keep DI clean.


Thats good to know. Could help 4.7L Dodge with the carboning exhaust valve stems that then stick and pop off rocker arms.

But Im still puzzled how it removes carbon from the intake valves on a DI.

 

[ahoier]

I still don't think the MMO or Seafoam can "hurt" - but you'd likely have to "keep on it" a regular basis.....to that I'd say, regular use of MMO 3-4 oz. per 10 gallons of fuel, every fill up. Or 1 oz of Seafoam per gallon of gasoline every fill up.

Either way, you're in for a chore

As far as "letting the dealer handle it under warranty" - I could agree with that....to an extent.....but in the end, when it comes down to it; I'm thinking they will act blind...not wanting to "fix" or "clean" anything til it actually "breaks" or otherwise causes a serious problem.....

Or [censored]....check into the TCW-3 craze

Seems to work similar to that of MMO in the fuel, only you use 1 oz. per 5 gallons, 2 oz. per 10 gallons, etc.....some claim MPG improvements, quieter engines, cleaner exhaust tips, etc....supposidely due to the fact that TCW-3 "burns hotter" it's capable of cleaning up the exhaust...may slightly take down the octane of your fuel, but with only 1 oz. per 5 gallons, I can't see it being that big of a deal. The big benefit seems to be keeping the fuel system, pump, lines, filter(s) all lubed up. Similar to that of MMO, and Seafoam.

 

[Bill in Utah]

NOTHING you can put in the fuel tank is going to do ANYTHING.

The problem is with the deposits in the intake system BEFORE the injectors. Since they don't don't see fuel to wash the deposits away you have problems.

My advise (which I gave and my family member followed two weeks ago) was if you have a choice, just say no to DI. If you have it be prepared to "deal" with it. No oil choice will eliminate it and it WILL be a issue IMO.

Nothing that anyone on BITOG can help you with.

Enjoy the new ride and be safe. Bill

 

[Gene K]

Originally Posted By: Bill in Utah
NOTHING you can put in the fuel tank is going to do ANYTHING.

The problem is with the deposits in the intake system BEFORE the injectors. Since they don't don't see fuel to wash the deposits away you have problems.

My advise (which I gave and my family member followed two weeks ago) was if you have a choice, just say no to DI. If you have it be prepared to "deal" with it. No oil choice will eliminate it and it WILL be a issue IMO.

Nothing that anyone on BITOG can help you with.

Enjoy the new ride and be safe. Bill



So I take it you dont think much of cleaners routed through the intake (via one route or another).

 

[ARB1977]

Bill hit the nail on the head. DI engines are great but are a pain for keeping intake valves clean. The only way to do so is by sucking sea foam through a vacuum line so it washes over the valves. Other than that that's pretty much it.

 

[ProfPS]

You have to understand that DI came out of the racing industry. DI is efficient and produces a good amount of HP, but they were designed for high RPMs: 7K+. Car manufacturers have move to this engine design and have installed them with 5 speed and 6 speed automatic transmissions that rarely go above 2k RPMs for high MPGs.

I suspect that diving the car like you stole it and put the transmission is the gear shift location to not go into 5th or 6th gear may help, but it defeats the MPG purpose of marrying the DI engine with a 5/6 speed trans. A CVT transmission may have better results with the carbon build up problem on the valves since the engine stays at a constant and higher RPM longer.

 

[demarpaint]

Nothing added to the fuel is going to help. An Inverse Oiler feeding MMO via a vacuum line is probably the best thing you can do at this point IMO. I'm willing to bet adding the Inverse Oiler early in the cars life and keeping it filled up will be the best thing you can do.

 

[wolfc70]

Originally Posted By: ARB1977
Bill hit the nail on the head. DI engines are great but are a pain for keeping intake valves clean. The only way to do so is by sucking sea foam through a vacuum line so it washes over the valves. Other than that that's pretty much it.


You would need to use Seafoam pretty frequently to help keep the intake valves clean. The only product I have seen that will actually remove heavy deposit build up is the BG 44 intake cleaners. Granted this is not a cheap option (most VW/Audi dealers charge $250 to do this), but it does work.

Intake deposits are nothing new, most automotive diesel engines with EGR have had this problem for years. But since diesel burns cooler, the deposits are usually not hardened like in GDI. On some engines, like the VW 1.9 TDI PD, you need to pull the intake manifold off to to clean that out.

Time will tell how the Hyundai GDI engines hold up, so far, I have not seen many complaints at all about valve deposits. Same for the GM DI engines.

 

[A_Harman]

Originally Posted By: ProfPS
You have to understand that DI came out of the racing industry. DI is efficient and produces a good amount of HP, but they were designed for high RPMs: 7K+. Car manufacturers have move to this engine design and have installed them with 5 speed and 6 speed automatic transmissions that rarely go above 2k RPMs for high MPGs.

I suspect that diving the car like you stole it and put the transmission is the gear shift location to not go into 5th or 6th gear may help, but it defeats the MPG purpose of marrying the DI engine with a 5/6 speed trans. A CVT transmission may have better results with the carbon build up problem on the valves since the engine stays at a constant and higher RPM longer.


I disagree with most of this. GDI engines may have first come to the public eye in racing at the LeMans 24-Hour, but that is not where its development started. Mitsubishi introduced wall-guided GDI engines into the Japanese market in the late '80's and early '90's, but they were not terribly successful due to problems with excess soot from the combustion process. (By the way, Hyundai built Mitsubishi's early GDI engines under license for sale on their large cars in Korea, so it's not like they have no previous experience with GDI.) Then in the '90's, Audi started developing spray-guided GDI systems with the intent of introducing it into production cars. Their efforts at LeMans with the R8 FSI engines were derived from their production car developments and gave Audi a very public demonstration that GDI engines perform. No manufacturer would have undertaken development of GDI fuel injection systems just for racing: the costs are too high for the very low volume of systems that could be sold. The cost could only have been justified based on selling millions of systems a year, not dozens.

The main benefits of DI are realized at low engine speeds, not high. At low speeds, the injection is timed to occur during the compression stroke in order to control the proximity of the fuel with the spark plug, and not allow fuel to accumulate in crevice volumes where it can't be burned. The system works well at low speeds because there is sufficient time to form combustible mixture. The problem with high speed operation is that if the fuel is injected on the compression stroke, there is not enough time for good mixture formation, and late combustion becomes more of a problem. Therefore at high speeds, DI engine injection timings are changed to the intake stroke so the fuel can properly evaporate and form a homogeneous mixture such as from a port-injected engine.

 

[Scum_Frog]

This is from the Shell V-Power website on the topic:

http://www.shell.ca/home/content/can-en/products_services/on_the_road/fuels/shell_vpower/

Today's engines are evolving and one technology at the forefront is a direct injection gasoline engine. With this system, the fuel injector moves directly into the combustion chamber subjecting the injector to greater heat and pressure. This can result in a breakdown of the cleaning agents in today's conventional additive formulations. New Nitrogen Enriched Shell V-Power gasoline is designed to maintain thermal stability under extremely hot engine temperatures found in today's most advanced fuel-efficient engines.


Using lower quality gasolines can allow gunk to build up on intake valves and fuel injectors. This gunk can cause less efficient mixing of air and fuel and can result in incomplete combustion. Tests show that Shell V-Power gasoline can remove gunky build-up left behind by lower quality gasolines and help your vehicle perform at its best. Sustained use of Shell V-Power gasoline helps to protect against new build up of gunk on those critical engine parts.

 

[lexus114]

Easy solution....DONT BUY ONE!

 

[09_GXP]

Another issue that some might not be aware of is increased wear on the intake due to the loss of the fuel wash which increases friction between the valve and the seat. From talking with industry experts its seems GM has decided to go with harder intake valves in all of its new prodcuts, even non-DI engines, to help combat this issue. The trade-off is higher cost upfront. I wonder if Hyundai is using harder intake valves or not, but it wouldn't surprise me if they elected not to in order to keep their products cost competitive.

To help control the deposits on the valves, some are designed to be "hot" so that at near max power they will actually get hot enough to "cook off" the deposits and keep the valves clean. So a spirited on-ramp acceleration to redline may not be a bad idea every once in awhile.

 

[beanoil]

I like MMO (standard dose of 4 ounce per 10 gallons)in my DI Equinox to keep the injectors lubed. DI's do run higher fuel rail pressures, and the injectors are stressed more than in a conventional FI engine. But all the statements are true. DI's beat up oil, contaminating it with fuel, and there are intake deposits that build up over time. Some oil manufacturers are recommending low saps oils for DI engines. The jury is still out, and most likely all you can do is delay the problem, not fix it. All that said, I still like my 10 Nox, and it's DI engine. Very smooth, responsive, and is returning better than 30mpg in steady highway droning when in eco mode. I've got 26k on it now, and it runs like new.