Fuel Injection Cleaning

toyota
gasoline
corolla

#1

I have read other threads her on Car Talk suggesting that a “Fuel Injection Cleaning” is generally a “wallet flush” and unnecessary. I’d like to clarify that it is the case in my situation.



I have taken 2 cars, mine and my wife’s to a private mechanic who is well-rated both here on Car Talk’s website and on Angie’s List. My car is a 2001 Toyota Corolla, stick shift, with about 110,000 miles on it. I bought it at 78,000 miles and as far as I can tell, it was dealer-maintained at least through 60,000 miles and I have done Owner’s Manual recommended maintenance on it since I have owned it. My wife’s car is a 2004 Corolla, automatic, with about 95,000 miles on it. It has lived as a rental car among other things in its more checkered history. We don’t have much information about how it was maintained before we bought it at 90,000 miles.



Anyway, this same mechanic has recommended a fuel injection cleaning on each car (I brought the cars in several months apart from each other). It is “especially recommended” on the 2001 Corolla because the 2001 Corolla “has no fuel filter”. The mechanic also recommends an automatic transmission flush on the 2004 Corolla.



I’d appreciate confirmation that a Fuel Injection Cleaning is inappropriate/unnecessary as has been previously posted, or that my case is different and it may be warranted. Thanks!


#2

A fuel injection cleaning as preventative maintenance is unnecessary. Any of the pump gas you can buy all contain enough detergents to keep those injectors clean. Fuel injection cleaning is only necessary when there is a contamination problem in the fuel system to save from replacing injectors.

The 2001 Toyota Corrola DOES have a fuel filter. This information is clearly incorrect. I don’t know of any car made in the last 50 years that did not have a factory fuel filter.

Also, I don’t do transmission flushes. I do a pan drop and filter change, refilling with fresh fluid. I’ve heard too many stories about flushes blowing out valves and solenoids. Plus, most flushes don’t include a filter change.


#3

When cars are running normally, their injectors are clean and don’t need to BE cleaned. Gasoline and its detergent additives are a VERY powerful solvent and cleaning agent by itself. The transmission should indeed be serviced, call it what you will, but this service should include dropping the pan and changing the filter…

If your mechanic says “That’s no longer necessary”, find a new mechanic…


#4

At high mileage a fuel injection cleaning can be beneficial. If everything in regards to the engine condition and igniton is normal and if you notice a slight stumble or shake at idle (even a very very slight one) then F.I. cleaning may help.

You would be surprised at how many engines that appear to be running fine to their owners improve a bit after an F.I. cleaning.

There’s nothing wrong with a transmission flush but the pan should be dropped and cleaned along with changing the filter first.


#5

I don’t know of any car made in the last 50 years that did not have a factory fuel filter.

My 1965 Sunbeam Imp did not have one. Sorry to say I added on and it broke creating quite a fire. Cheap US made hose broke.


#6

I have sent in a couple of sets of injectors to be cleaned, but in both cases, the car had over 200k miles on it, and I was trying to isolate a problem and the injectors were a suspect. I pull them out and send them to a shop that tests the flow volume, leakage, and spray pattern before and after ultrasonic cleaning. I would not spend a dime for the in-place cleaning that is done in mechanic shops (unless it only cost about a dime). Even if it improves the symptoms, you really don’t know if your injectors are uniform and completely up to spec after an in-place cleaning because there is no way to test them.

As for transmission flushes. I have never done it and see no real reason to. I change the fluid and filter periodically, but the fraction of the fluid that is in the torque converter stays there and blends with the fresh fluid. If the fluid is so bad that it needs to be completely removed, odds are that the tranny is toast anyway.


#7

I agree with Manolito 100% on the transmission flush. As for transmission flushes. I have never done it and see no real reason to. I change the fluid and filter periodically, but the fraction of the fluid that is in the torque converter stays there and blends with the fresh fluid. If the fluid is so bad that it needs to be completely removed, odds are that the tranny is toast anyway.