SyberTiger
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- May 18, 2007
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- Year, Model & Trim Level
- 2002 Limited 4x4 4.6L
This thread obviously isn't for those of you with advanced maintenance skills as the following information contains information for a process you've done on at least one occasion. However, in the interest of documenting the process of locating and cleaning the MAF Sensor and IAC valve I've created this thread with pictures and my take on how to clean these two items.
Those of you reading this thread no doubt have experienced some of the following issues with your Explorer: (1) Difficulty starting, (2) Engine dies after starting, (3) Rough idling, (4) Hesitation or stuttering under load or throttle position change, (5) Engine running too lean or too rich. If you've experienced one or more of these problems then this thread may be for you.
With regard to the IAC valve only the 2002 and 2003 3rd generation Explorers have them as a separate item. If you have a 2004 or higher Explorer then ignore the IAC valve cleaning instructions. Feel free to add your experiences with this process.
Cleaning the MAF Sensor
The MAF Sensor in located between the air filter and the intake. To access the MAF Sensor disconnect the electrical connection (green circle), unbuckle the air filter straps (red circles), and loosen the hose clamp (blue arrow).
The MAF Sensor is physically bolted to the air filter cover. There is no reason to unbolt the MAF Sensor assembly from the air filter cover. Simply, pull off the air filter cover with MAF Sensor attached.
With the air filter exposed now is a good time to remove it and inspect it. Change out the air filter if needed and don't forget to vacuum out the lower part of the air filter box to get rid of the sand, dirt, and bugs you'll find in there.
To clean the MAF Sensor purchase a can of cleaner specifically made for cleaning MAF Sensors. Do NOT use carb or intake cleaner or any other solution or you'll damage the MAF Sensor.
The process to clean the MAF Sensor is nothing more than spraying the heck out of the MAF Sensor heating wires. Do NOT touch the sensitive wires with anything or you'll risk damaging the MAF Sensor.
There are two wires within the MAF Sensor assembly. Thoroughly spray down the wires at all angles. Use at least a half can if not more of your MAF Sensor cleaner. Again, be careful NOT to touch the wires. You now have clean the MAF Sensor. Reassemble the components in reverse.
Cleaning the IAC Valve (on 2002/2003 Explorers)
The IAC Valve is access by removing the engine acoustic insulator. Remove the two 7/16" bolts (blue arrows).
There is a plastic hose clamp (blue arrow) that needs to be undone so the hose may be detached from the acoustic insulator. The acoustic insulator may now be removed by grabbing the back corners of the acoustic insulator with a hand on each side then pulling straight up. The rear portion of the acoustic insulator is being held down by two rubber grommets contained in the acoustic insulator sitting on top of two posts. Refer to the picture after this one.
The red arrows point to the previously mentioned posts that the rear portion of the acoustic insulator lock onto. The IAC valve is circled in blue.
To remove the IAC Valve first unplug the hose (green circle). It pulls straight off. Next unplug the electrical connector (red circle).
Next, remove the two 5/16" bolts (blue arrows). With the bolts out carefully remove the IAC valve being careful not to lose or damage the gasket.
The intake side can now be seen.
The intake should be carefully cleaned using Throttle Body and Air Intake Cleaner. Spray it liberally and use Q-tips to clean out the carbon buildup. Clean it first to allow it to air out and dry prior to reassembling the IAC Valve.
With the IAC Valve off. Thoroughly and liberally spray the IAC Valve opening for the intake mount side. Use Q-tips to clean out the carbon and other gunk.
It might take a little patience and time to clean it out.
Next, clean out the hose side of the IAC Valve. Again, liberally spray it out and use those Q-tips to clean it out.
With the IAC Valve nice and clean it is time to reassemble it. The process obviously goes in reverse to remount it. You may want to consider picking up a new gasket from your local Ford dealer. The cost is under $2. If your gasket is in good shape and not brittle then feel free to reuse it.
That's all there is to it. It's not much more difficult than changing the oil. Cleaning the MAF Sensor and IAC Valve every 30K miles or so will help keep your Explorer running in tip-top shape. Hopefully, this simple maintenance procedure cures whatever problem that first brought you to this thread. If not then a new MAF Sensor or IAC Valve could be in your future.
Those of you reading this thread no doubt have experienced some of the following issues with your Explorer: (1) Difficulty starting, (2) Engine dies after starting, (3) Rough idling, (4) Hesitation or stuttering under load or throttle position change, (5) Engine running too lean or too rich. If you've experienced one or more of these problems then this thread may be for you.
With regard to the IAC valve only the 2002 and 2003 3rd generation Explorers have them as a separate item. If you have a 2004 or higher Explorer then ignore the IAC valve cleaning instructions. Feel free to add your experiences with this process.
Cleaning the MAF Sensor
The MAF Sensor in located between the air filter and the intake. To access the MAF Sensor disconnect the electrical connection (green circle), unbuckle the air filter straps (red circles), and loosen the hose clamp (blue arrow).
The MAF Sensor is physically bolted to the air filter cover. There is no reason to unbolt the MAF Sensor assembly from the air filter cover. Simply, pull off the air filter cover with MAF Sensor attached.
With the air filter exposed now is a good time to remove it and inspect it. Change out the air filter if needed and don't forget to vacuum out the lower part of the air filter box to get rid of the sand, dirt, and bugs you'll find in there.
To clean the MAF Sensor purchase a can of cleaner specifically made for cleaning MAF Sensors. Do NOT use carb or intake cleaner or any other solution or you'll damage the MAF Sensor.
The process to clean the MAF Sensor is nothing more than spraying the heck out of the MAF Sensor heating wires. Do NOT touch the sensitive wires with anything or you'll risk damaging the MAF Sensor.
There are two wires within the MAF Sensor assembly. Thoroughly spray down the wires at all angles. Use at least a half can if not more of your MAF Sensor cleaner. Again, be careful NOT to touch the wires. You now have clean the MAF Sensor. Reassemble the components in reverse.
Cleaning the IAC Valve (on 2002/2003 Explorers)
The IAC Valve is access by removing the engine acoustic insulator. Remove the two 7/16" bolts (blue arrows).
There is a plastic hose clamp (blue arrow) that needs to be undone so the hose may be detached from the acoustic insulator. The acoustic insulator may now be removed by grabbing the back corners of the acoustic insulator with a hand on each side then pulling straight up. The rear portion of the acoustic insulator is being held down by two rubber grommets contained in the acoustic insulator sitting on top of two posts. Refer to the picture after this one.
The red arrows point to the previously mentioned posts that the rear portion of the acoustic insulator lock onto. The IAC valve is circled in blue.
To remove the IAC Valve first unplug the hose (green circle). It pulls straight off. Next unplug the electrical connector (red circle).
Next, remove the two 5/16" bolts (blue arrows). With the bolts out carefully remove the IAC valve being careful not to lose or damage the gasket.
The intake side can now be seen.
The intake should be carefully cleaned using Throttle Body and Air Intake Cleaner. Spray it liberally and use Q-tips to clean out the carbon buildup. Clean it first to allow it to air out and dry prior to reassembling the IAC Valve.
With the IAC Valve off. Thoroughly and liberally spray the IAC Valve opening for the intake mount side. Use Q-tips to clean out the carbon and other gunk.
It might take a little patience and time to clean it out.
Next, clean out the hose side of the IAC Valve. Again, liberally spray it out and use those Q-tips to clean it out.
With the IAC Valve nice and clean it is time to reassemble it. The process obviously goes in reverse to remount it. You may want to consider picking up a new gasket from your local Ford dealer. The cost is under $2. If your gasket is in good shape and not brittle then feel free to reuse it.
That's all there is to it. It's not much more difficult than changing the oil. Cleaning the MAF Sensor and IAC Valve every 30K miles or so will help keep your Explorer running in tip-top shape. Hopefully, this simple maintenance procedure cures whatever problem that first brought you to this thread. If not then a new MAF Sensor or IAC Valve could be in your future.
