Airflow sensor cleaning

[JPMC]

As most of you know the engines in our Nav's are quite bad for blow-by fumes in the intake. As a result I regularly (every 6 months or so) clean the airflow sensor to keep everything running smoothly. The first time I did it the Nav had 40,000km (25,000 miles) and it was that dirty I couldn't see the colours of the diodes.

This would also be a must for anyone running an aftermarket oiled air filter (ie K&N)

Anyway was doing today so thought I'd write a how to for everyone else.

Tools required are a 7mm spanner and a can of electrical contact cleaner.

First off locate the airflow sensor in the air intake tube just down from the air cleaner.

There is two screws with 7mm hex that need to be undone.(one top and one bottom).

After removing the screws slide the sensor out.

Once the sensor is out look on the side and you will see an opening with a couple of wee diodes inside.

See next post for part 2.

 

[JPMC]

Part 2


Now get your hands on some Electrical contact cleaner.

Spray the cleaner into the opening.

*****I should mention at this time to never touch the diodes with anything except the electrical cleaner as touching with fingers, rags, cotton buds or anything else can or will damage the sensor.****

Wait for the sensor to dry and the spray to evaporate away and the diodes should be nice and cleaner but if not repeat the spray and allow to dry again.

Now it's just a matter of putting the sensor back into the intake and replacing the screws and your all done.


.

 

[53ANO]

what are the advantages of doing this... ?

 

[Dave]

Keeps the engine running the best as the sensor measures the ammount of air going into the motor.

Dave.

 

[JPMC]

Yeah.

With a dirty sensor it can run ruff and hesitate under acceleration and in my case the first time I did it my fuel consumption decreased.

 

[53ANO]

sweet thanks guys, just did mine

 

[jackhon]

THx Good info....

 

[jjohn]

Well done, you should be a teacher. look'n at a catch can to limit the blow by. that should mean I will have to clean the sensor less often or never? as well as NO or little oil into intake air.

 

[Old.Tony]

This is a thread I completely missed, not sure why. This is the sensor Bosshog just had trouble with (called the MAFS in the manual). I think mine's going to come out for an inspection and a clean.

I'm not sure blow-by would get into it - it's upstream of the PCV connection, and blow-by can only happen while the engine is running so the air is moving inwards from this point, making it nearly impossible for blow-by to affect the MAFS. Doesn't mean I will change my mind about a catch can - but it does mean that I'm not worried about blow-by with this.

What does concern me is if there is anything found in this sensor. It's only just inside the airstream from the filter. If there's ANYTHING on the sensor, that stuff has made it past the filter - so my concern is for the filter's operation, and for the rest of the engine, because if the MAFS has crap land on it, that crap has made it into the turbo and engine as well.

 

[Bosshog]

Likewise I missed this thread too. All I have to add is look after your MAFS coz once it throws a wobbly its time for a tow truck.

 

[joffo81]

As most of you know the engines in our Nav's are quite bad for blow-by fumes in the intake. As a result I regularly (every 6 months or so) clean the airflow sensor to keep everything running smoothly. The first time I did it the Nav had 40,000km (25,000 miles) and it was that dirty I couldn't see the colours of the diodes.

This would also be a must for anyone running an aftermarket oiled air filter (ie K&N)

Anyway was doing today so thought I'd write a how to for everyone else.

Tools required are a 7mm spanner and a can of electrical contact cleaner.

First off locate the airflow sensor in the air intake tube just down from the air cleaner.

There is two screws with 7mm hex that need to be undone.(one top and one bottom).

After removing the screws slide the sensor out.

Once the sensor is out look on the side and you will see an opening with a couple of wee diodes inside.

See next post for part 2.

This may sound stupid but I can't even find the MAFS! I have an 06 D22 with the ZD30 in it. Can anyone help me as I would love to find it and clean it. Are the pictures above from a D22 or D40? The air filter in my ute is round and the one in the pics seems to be square. Any help would be appreciated.

 

[Dave]

The D22 ZD30 doesn't run a MAF sensor. They run a MAP sensor.

Thats a D40 engine bay mate.

The MAP sensor doesn't need cleaning.

 

[joffo81]

That would explain why I cant find it then! Thanks for your prompt reply Dave. I'll cross that job off my list for the weekend!

 

[Scubamurph]

I pulled mine out yesterday and it was fitlhy with what looked like soot.
A quick squirt of contact cleaner and all clean again

Not noticed any change in how she drives but will check economy after this tank fo fuel.

Great guide mate. Thanks.

Regards Murph

 

[jjohn]

Yeah I'm with you Tony. Seems ridiculous to have ANY dirt, soot etc on the MAFS. Looked at the point where the blow by enters the air inlet from inside. The blow by makes it's way back up that inlet towards the air filter box a little, oil stains about 80mm up. Only thing I can think is it's a bit of oil fumes just after backing off the loud pedal?

 

[kika]

hi all, just registered, got a 2009 d40 twin cab 2.5. just put a safari snorkel on (fitted my sellf pretty easy) but my fuel consumption went from 650 klm per tank to 550 klm per tank. i cleaned the airflow senser. Any ideas?

 

[Old.Tony]

Welcome to the forum, Kika.

If you're getting a lot more black smoke than usual from the exhaust I'd say intake restriction. The snorkel - bends and all - are all larger than the inner diameter of the turbocharger intake so it's unlikely to be the snorkel unless there's something stuck in it somewhere.

It might just be the ECU learning a different fuel mix. It does modify the fuel rail pressure based on throttle position, gear, engine load, air flow (measured at the MAFS just outside the airbox on the tube heading towards the turbocharger), boost pressure and intake air temperature. Changes in any of these can affect how the ECU applies pressure to the rail, and even how it adjusts the timing.

Furthermore, on cold days the intercooler is much more effective than on warm days so that too plays a part.

You could try an ECU reset - get your radio PIN, write down the tripmeter values (if you use those to record fuel usage) and remove the battery negative lead. Put your foot on the brake pedal, then go and reattach the negative lead - presto, ECU reset.

 

[kika]

thanks for that. ill give it a go

 

[D22Nav_Man]

Welcome to the forum, Kika.

If you're getting a lot more black smoke than usual from the exhaust I'd say intake restriction. The snorkel - bends and all - are all larger than the inner diameter of the turbocharger intake so it's unlikely to be the snorkel unless there's something stuck in it somewhere.

It might just be the ECU learning a different fuel mix. It does modify the fuel rail pressure based on throttle position, gear, engine load, air flow (measured at the MAFS just outside the airbox on the tube heading towards the turbocharger), boost pressure and intake air temperature. Changes in any of these can affect how the ECU applies pressure to the rail, and even how it adjusts the timing.

Furthermore, on cold days the intercooler is much more effective than on warm days so that too plays a part.

You could try an ECU reset - get your radio PIN, write down the tripmeter values (if you use those to record fuel usage) and remove the battery negative lead. Put your foot on the brake pedal, then go and reattach the negative lead - presto, ECU reset.

Does that work on the d22. Is it some thing worth doing every now and then????

 

[Old.Tony]

The D22 doesn't have the same sensors, but if it's learning the wrong fuel maps then sure, try an ECU reset and see what happens. It can't harm the vehicle, at worst it will lose the trip meter values and require the PIN for the radio.