It’s a fact that deposits form in every fuel system but the amount and how quickly they form depend on the quality of fuel, the oil used, personal driving styles, and engine type.
Some engines are particularly prone to wrap and buildup of fuel deposits because they’re never cooled or washed with fuel. Carbon deposits can form in as few as five thousand to ten thousand miles causing restricted airflow and increased engine operating temperatures. So, here is how to clean the intake valve without removing it:
1. Wear protective glasses and gloves
This is an obvious thing since safety is always number one. In order to safely clean the intake valve without removing it, please wear protective glasses and gloves. The cleaning product is applied with the engine running and you do not want to burn your hands or risk any fluids from the running engine getting into your eyes. (See some gloves and glasses on amazon.com).
I work around cars a lot and I used to forget to put on my gloves or my glasses. You know, when you work on cars all day and you want to get things done, you forget about your safety. I used to come home with very dirty hands and skin burns on my fingers. My wife didn’t mind the dirty fingers because those fingers put food on the table, but she told me one day that she respected my work but I could be a lot cleaner and without injuries, if I only put on the protective gloves. So, me being a good husband, I did put on the gloves and made it my habit. It’s not bad to listen to the other half from time to time.
2. Get the engine to operating temperature
In order to clean the intake valve without removing it, you have to start your engine and get it at operating temperature. Most engines operate at 195 to 220 degrees Fahrenheit. A great way to know that your engine is at its operating temperature is by looking at the temperature gauge on the dashboard. Once the temperature gauge is in the middle between C (cold) and H (hot) that’s how you know that your engine has reached its operating temperature.
3. Remove the air filter cover
The air filter has a plastic cover that has to be removed in order to get access to the MAF sensor. The air filter cover is located near the engine and has a duct that travels from the front of the car into the engine. To remove the air filter cover, you need to loosen the hose clamps on each side and remove any wing nuts (if present). Make sure that you don’t lose any of the parts because you will need to reassemble the air filter cover later.
While you are at it, you can check the condition of the air filter and replace it or clean it if necessary. I always recommend changing the air filter with a brand new one because they are not that expensive (check prices on air filters on amazon.com).
4. Locate the MAF sensor
The MAF sensor is a part of the electronic fuel injector system and has a function to calculate the amount of air that is entering the engine. The combustion that occurs in the combustion chamber has to have a specific air to fuel ratio, otherwise, the vehicle will run rich or poor. The mass airflow sensor is in charge of the air intake.
The mass airflow sensor, also known as the MAF sensor is usually located between the airbox and the throttle body. It is important to locate the MAF sensor because you are going to spray the valve intake cleaner past the MAF sensor.
5. Rev the engine to approx. 2,000 RPM
For this step, it’s best if you have someone behind the steering wheel that will be able to rev the engine to approx. 2,000 RPMs. Revving your engine to approx. 2,000 RPMs will get the engine running and will speed up the combustion process.
6. Insert the cleaner straw past the MAF sensor
This is an important step. You should only spray the cleaning product after the MAF sensor. If you spray the cleaning product in front of the MAF sensor, you will see a check engine light on your dashboard.
If you have an OBD Scanner (see prices on amazon.com), you will be able to scan your vehicle for error codes. Usually, the error code associated with the mass airflow sensor is P0102. Since you will know what caused the error code, you could go ahead and remove it.
7. Spray the intake cleaner
With the engine running at approx. 2,000 RPMs, go ahead and spray the intake cleaner (see the price on amazon.com) in 30-second intervals until the can is empty. If you feel that the engine is beginning to stall, press the gas pedal but do not exceed 3,500 RPMs.
The spray cleaner will be able to remove a lot of the carbon deposits that accumulated on the intake valves. It is important that you pay attention to where you are spraying the intake cleaner. Some vehicles have intake manifolds designed in a way that they will allow the intake cleaner to ”pool” in one place. What could happen next is when you are driving down the road, the intake cleaner could end up past the valves and trigger error codes on your dashboard.
8. Rev the engine up to 3,500 RPMS
When the intake cleaner can is empty, accelerate the engine 2-3 times over 2,000 RPMs, but again do not exceed 3,500 RPMs. Run the engine idle for one minute and then turn off the engine.
9. Re-assemble the air intake system
After you are done with the spraying and revving your engine, it is time to reassemble the air intake cover. While you are at the air intake filter, inspect it and replace it if needed.
Then, turn the engine off and lead the engine head-soak for an hour. This will allow the intake cleaner to really clean the intake valves from the carbon deposit. Once one hour passes, drive your vehicle at highway speeds for at least 10 minutes. At this point, you should have clean intake valves.