Cleaning the injectors and throttle body on LFX

[Backspin9]

Had the car in for the last of my free oil changes. The dealer recommended cleaning the fuel system and the throttle body. The car has 18K miles on it and I put a VMAXX ported TB on it at about 10K miles. It also has a catch can.

They want $150 to do this and cost aside, is it really necessary? I doubt the throttle body needs to be cleaned with only 8K miles on it. Being a DI engine, what could they possibly do besides putting something in the gas tank?

[Abelardoo_12]

Last time I had my car at the dealer they really recomended me to get the injectors cleaned and as curiosity I asked how they would do that and said they plug in a machine straight to the injectors and somehow clean it like that. I called around a couple of shops around my area and nobody knows about that method. But my car has 80k miles, with your milage being so low I'd say you wouldn't needed, just put the cleaner in the gas tank every once in a while and you'll be good

[JerTM]

Depending on the chemical company they use there are a couple ways they clean the fuel system. Generally it involves and additive in the tank, then another chemical used as fuel. The chemical is put into a pressurized container, they disconnect the fuel feed line and disable the fuel pump. Connect the pressurized container to the fuel rail and start the car and let it run until it the chemical is used up. That is what they are referencing as a fuel system cleaning. The throttle body cleaning is usually a chemical put into the same pressurized container as the fuel clean but they put a spray nozzle on it. They remove the intake to the TB, disconnect the maf to make it run and start the car. Then they spray the throttle plate and TB wall to remove any buildup that may be there, it may help clean off the top of the valves a bit as well. Having said that, I don't believe in the fuel injection cleaning especially if you use a good fuel anyway. The TB clean can be achieved with a clean rag and some brake parts cleaner with similar results aside from possible valve cleaning.

[Elite Engineering]

What it sounds like the dealer is recommending is a solvent based engine running upper induction cleaning like a BG or Seafoam treatment.

As you have a GDI engine, we do not recommend this. While safe with the old port injection engines and the "soft carbon" deposits, GDI engines produce a hard crystalline and very abrasive deposit and when shed during such a procedural cause scouring and damage to the pistons and cylinder walls. ONLY a manual intake valve cleaning is safe to effectively clean your valves (do a search here on step by step instructions and pictures). Also, the solvent based engine running cleaning rarely remove more than 20% or so of the deposits.


Fuel injectors rarely get dirty on GDI engines as they operate at 500-3000 PSI and very hard for any deposits to form in them, but running a top tire fuel will keep them from every getting dirty (top tier fuel has NO effect on any internal portion of the engine including valves as fuel touches nothing any longer, but is good for injectors.)


The TB you remove and manually clean with TB cleaner and a rag. Do that yourself. But NEVER do or allow a engine running solvent cleaning. You may not notice the damage it causes right away, but we have yet to tear down a GDI engine and not see damage to the piston skirts and cylinder walls from the hard almost sand like particles forced between the piston and wall from one of these. Great profit generators for dealers and shops, but look at BMW and how they pioneered GDI and the proper way to clean valves.

[christianchevell]

Thank you! You just reminded me to go add some Lucas upper cylinder lubricant...cleans my injectors and helps poor quality gas along with lubricating important things and cleaning the cylinders...... Just a thought. A good engine cleaning would be more in the line of a 100000k mark with our cylinder sealing, though I have heard the v-6 is a little dirtier with guys running sea foam treatments eventually.

For a throttle body just lightly spraying it with a maf/TB cleaner can clear up the reside of the air filtration system and can be sprayed on then cleaned with a soft lint free rag or done running which may also clean injectors but with out a carb is much more likely to stall the engine with fuel injection...that's what I do anyway.... and your catch can is a good thing. Going to go clean mine and change my separate clutch reservoir right now.