Throttle body "optimization"?

During a recent routine service of my wife’s car (2014 Hyundai Elantra, 30K miles), the dealer service department called her and recommended she have the throttle body “optimized” by cleaning out the carbon that builds up because the engine is gas direct injection and has an extra fuel pump. They said it would increase the mileage and efficiency and cost about $200.

This sounds like total hooey to me. How would carbon build up in the the throttle body, where no combustion takes place? What does the EFI fuel pump have to do with it? I can see where eventually you would get some varnish or residue from the evaporation of unburnt fuel that might need to be cleaned out, but probably not a significant amount in just 1 year and 30K miles. And $200 to disconnect the air intake and hose it down with solvent? I think they were trying to scam her.

What say ye all?

This optimization is real, it optimizes the bottom line for the dealer. There is no need for this. If you are having symptoms - maybe, but a car this new should not be having any drive ability problems.

There has been some recent discussion on this topic. Apparently, this problem is actually worse on DI engines as the atomized fuel does not flow past the back side of the valves, like in prior wet intake designs, and can’t help to clean them off. How does stuff get on the valves or further upward in the tract? Valve overlap allows back belching and the PCV system is upstream on most designs…

I really doubt it’s a problem on your 2014. I would refuse unless/until I notice any drivability problems, unless it’s listed in your owner’s manual (which I doubt).

Thanks all. Very helpful. It’s not as simple or unrealistic as I thought, but also probably not necessary at this point. I like the comment about optimizing the dealer’s bottom line.

Dealers try this hooey on regular, non-di, engines too. It is called by several names, Injector Flush, Power Clean and many more. If the engine is running OK you don’t really need this. The dealer needs this, he has a boat payment.

Carbon buildup on a vehicle this new?? No way. If it is…then I’d sell it…there’s a serious problem - either manufactured or designed.

Mike, it’s not unusual for direct injection. Good luck selling it to eliminate the problem because almost all new engine designs use this approach and are subject to this side effect. Many people are finding this out the hard way. It’s all over the boards I frequent for some time now. Welcome to the new world…

Remember, we’re not talking about inlet valve carbon buildup, but throttle body buildup which also occurs with port injection.

Yeah, it’s a scam.

There’s always 2 sides to every coin. Odds are your car does not need this and the service is being pushed as a profit generator more than anything else. There’s different ways of going about this process and some are more complicated than others.

That being said, the assumption that a new car with only 30k miles does not need the service may be incorrect. A lot depends upon environmental conditions and driving habits. If the mileage is accumulated with mostly short hop driving then the odds of needing this type of service increases.
The same thing applies to fuel injection cleaning. The blanket statement that it’s never needed is also incorrect.

I’ve related the story about dropping into the local Lincoln dealer parts dept. one time and on the way out spending a few minutes talking to a friend of mine who works there as a mechanic. He was in the middle of an induction cleaning on a Lincoln Town Car which belonged to an elderly lady. The car had about 30-40k likely short hop miles on it, the intake manifold was off of it, and to be blunt; it was nasty and as gunked up as could be.
It would have been a miracle if the EGR system passed any gas at all… :frowning:

Hyundai has problems with dirty throttle bodies causing drivability problems and setting fault codes. This is from bulletin 13-FL-002;

This bulletin provides the procedure to clean the Electronic Throttle Control (ETC) throttle body. If a vehicle exhibits the condition(s) listed below and deposits are found at the valve-to-bore interface inside the ETC throttle body, clean the throttle body using the procedure described in this bulletin.
Applicable Vehicles:
Elantra (UD/MD/GD/JK): 2011 ~
Genesis Coupe (BK) 2.0L: 2010 ~
Santa Fe (CM) 2.4L: 2010 - 2012
Santa Fe Sport (AN): 2013 ~
Sonata (NF) 2.4L: 2006 - 2010
Sonata (YF): 2011 ~
Tucson (LM): 2010 ~

Any of the following conditions may be caused by throttle body deposits:

No start (due to throttle valve stuck closed or air flow significantly restricted)

Rough idle or fluctuating engine speed at idle (due to air flow restricted)

MIL “On” with DTC P2118 or P2119 occurring along with P2110:

P2118: Throttle Actuator Control Motor Current Range/Performance

P2119: Throttle Actuator Control Throttle Motor Current Range/Performance

P2110: Throttle Actuator Control System-Forced Limited Power

This should be less than one hour labor. For $200 this must include a full detail and lunch.

On a 2014 model? My “hooey-meter” is also maxxed out.

Do not,do it!

I wouldn’t monkey with the throttle body unless there is a symptom. Don’t know about this particular car, but the throttle body on my Corolla gets most of the gunk in it from the PCV system.

If one of these dealers would buy a bore scope and show a picture of some buildup maybe they could make some money by cleaning it out. Maybe they won’t do that because their stuff doesn’t work. They’re better off if they just sell, sell, sell. Once they learn how to sell they can’t stop themselves.

What DYI options work for cleaning valves on DI engines?

Do the BG or CRC cleaning solutions work?

I would think any of the products that are introduced into the intake before the the valves to fog the area and soak would work pretty well. We all have our favorites. I’ve heard good things about BG, products as well as Seafoam. I’ve tried CRC, Gumout and Seafoam but I don’t own a DI engine.

The OPs car exhibited none of the symptoms listed in the TSB and with 30000 miles on a 2014 I doubt if it is used mainly for short hops.
Pushing this kind of service absent any symptoms is just pure wallet flush.

If the Elantra has the 2.0L engine it is GDI. If it has the 1.8L engine it is not a GDI engine. Only the Sport and GT have the 2.0L engine. Plus it’s all part of the old talk about cleaning out the fuel delivery system - if you are using good quality gas you don’t need to worry about it, or you could just add a bottle of Techron fuel additive every 10-15K miles.

if you are using good quality gas you don’t need to worry about it,
or you could just add a bottle of Techron fuel additive every 10-15K miles.

Two things have be puzzled or curious:

  1. The GDI carbon buildup problem is with carbon building up on the backside of the valves where the injected fuel is no longer ever seen. How will using quality gas affect this?

  2. Adding a fuel additive, like Techron, may help the injectors, but how will it help to clean the back of the intake valve when the injector is spraying directly into the cylinder?

Isn’t the GDI valve carbon buildup occurring because of the dirty EGR gases hitting the backside of the intake valve? (Where previous TBI injection effect of “washing and cleaning” the backside of those valves no longer exists.)