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What happens when you have a fuel injector cleaning?

I am looking at having my dealership do a fuel injector cleaning on my 2011 Cadillac CTS4 3.0 with about 85,000. The reason I am looking at doing it is that my car seems to idle poorly at times when at stop lights and such. Back in November I had the spark plugs and coils replaced and had the Throttle body cleaned so looking at this as the next step. I have never had this done before on any car.

What is done when they do this cleaning? What is a “fair price” to have this service done at a dealership. I am doing my 6 month oil change done at the same time at the dealership (they offering a sale on it which is why I going there) so figured it would be a good time to get this done.

Add a bottle of seafoam to your gas. If necessary do this at each fill-up for a 3-5 fill-ups. If that doesn’t clear it up, then take to dealer.

BTW…it may not be fuel. Many other things can cause poor idle. Vacuum for one. I’d get that checked out first before I started pouring chemicals into tank.

They connect a device like this to the fuel rail.

They fill it with the cleaning solvent and pressurize it with compressed air.

They disable the fuel pump by removing the fuel pump relay.

They open the valve on the device and then start the engine

The engine runs off the cleaning solvent while at the same time cleaning the injectors.


Notice you are getting the same advice you got on your last post about this subject. Add a fuel injector cleaner to the tank and see what affect it has.

I got the impression that those OTC “cleaners” may have a bit, they really don’t do a full cleaning of the fuel injectors like the process that the dealership does and that this process should be done on a car like mine that has 85000 miles and is mainly a city driver car.

They may not…but those dealership cleaner systems are not really needed most of the time. I’ve had vehicles run for over 300k miles without ever using a service like that and never ever had a fuel related problem. Only recently have I started using a top-tier gas because a local chain (Irving Gas) near me started selling top-tier gas.

Since this is a 2011 GM, not too familiar with what type of filter they use. Is it an inline filter that can be easily replaced? Or is it a back-flush system inside the tank? If it’s the inline filter, when was the last time it was replaced?

I don’t disagree that you are getting a more thorough clean with the thru-the-fuel rail systems. You aren’t risking much by trying a couple of tankfuls of the additive types, though.

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Since this car has a direct-injection engine, this service may be a good idea. But I’m not seeing a lot of engine-related complaints online.

How much are they asking?

The cost for them to do the fuel injector cleaning is $149 and the synthetic oil change is $49 so total Im out $200 at the dealership.

I was offered a similar service at a dealership, I think for $179.99. I wasn’t having any problems, so I turned it down - I’m thinking it’s a money-maker (although it likely does have some benefits) so they offer it even without a report of a problem.
Price-wise, it looks reasonable and likely with little risk of hurting anything - although I don’t know how effective it will be. If dropping the money and not having it fix the problem would drive you crazy, try the additive route first.

You need an oil change, right? So you aren’t “out” $49. Your question is if $149 for fuel injector cleaning is warranted.

Since this car is direct injection, I’d opt for an “Intake Cleaning” rather than injector cleaning. Solvents are introduced into the incoming air stream to clean the front side of the valves that no longer get washed by incoming fuel. But you didn’t ask about that. But that is useful on a DI engine.


Yep it’s oil change time as my guage is at 9% and it’s been 6 months. What is involved in the type of cleaning you are suggesting?

Direct injection engines spray the fuel directly into the cylinder. The fuel never passes the intake valves but recirculated crankcase oil vapor does… soo the intake valves can get nasty deposits. Chemical cleanners from Seafoam, CRC BG and more are injected usually through a vacuum port between the throttle plate and the head. Let them soak a bit and restart the car to blow out the crud. Some engine are more susceptible than others to buildup. If you don’t clean it off chemically, it may have to be scraped out or blasted with walnut shells to clean.