I’d been having problems with oil leaking from the turbo in my PB Challenger and had also noticed a significant decrease in fuel economy. This was coupled with an increase in black smoke blowing from my exhaust under moderate to light loads. In a previous post, you can read all about my turbo replacement, but I’d also been told that cleaning the MAF sensor might also make some difference in regards to fuel economy and black smoke.
What’s a MAF Sensor?
MAF stands for Mass Air Flow. So the sensor sits between your air filter and your turbo and detects the temperature, density and quantity of air flowing into the engine. The computer then calculates the correct balance of fuel and air to achieve maximum efficiency. However because the MAF sensor sits in the air-flow, and your air filter isn’t perfect, after a time it gets dirty. Once it’s dirty it can give inaccurate readings to the computer.
What you’ll notice if you have a dirty MAF sensor is a decrease in fuel efficiency and more black smoke in your exhaust.
Luckily cleaning it is very simple. But you do need to take care.
Locating and cleaning the MAF Sensor
The sensor itself is very easy to locate. Open the bonnet and locate the turbo and the air filter. Between the two is a fat pipe that has a plug with electric cables running to it. It looks like this:
Removing it is quite simple. There are a couple of screws that you remove. Then pull it out. You can unplug the electric cables as well.
Take great care once this is removed. You don’t want to drop anything down the hole that is left behind. There is nothing between the MAF Sensor and the turbo. Anything you drop in there will go straight into the turbo and the engine. They’re not designed for handling screws and nuts and screw drivers so keep those kinds of things out.
Mine looked like this. Take a look at the tiny bulb thing. That’s the temperature sensor. It’s completely covered in dust, as is the whole device.
Cleaning the MAF Sensor is very easy. But you need to use the correct stuff. I went to Supercheap Autos and purchased some CRC Mass Air Flow Sensor Cleaner.
Following the instructions on this, I was able to clean the MAF Sensor quickly and easily. Give it a good squirt all over, inside and out… Afterwards it looked like this:
Take a look at that little bulb thing. That’s more what it’s supposed to look like! Semi-see-through.
What’s the difference?
So the big question is, “What difference did it make?” Well before I did this, I had people behind me commenting on how much smoke i was blowing under only very minor load. Like going up a hill, or taking off from lights. My fuel efficiency was down to about 450mks on a full tank of fuel (as reported on the dash). And towing our camper trailer seemed much harder than I thought it should be.
After the turbo replacement AND the MAF Sensor clean, towning the camper is much better, I have almost no black smoke even under reasonable load and last time I filled my tank it said I had 620kms in it. Most of our driving is around the city…
So did it make a difference? Yeah it really did! What made the most difference? Unfortunately I don’t know because I cleaned the MAF Sensor pretty much the same day they replaced the turbo.
But my neighbour borrowed my MAF Sensor cleaner to clean the one on his Navara and he said that it made the world of difference. We’ll be cleaning our MAF sensors regularly from now on.
Would I recommend that you do it yourself? Only if you’re a handy person. It’s not a difficult job but with any mechanical activity on your car, you do it at your own risk.