MAF Sensor

[LarryM]

While doing a routine inspection prior to the upcoming 3K tow, I see that the MAF sensor and the intake tube have a light coating of oil from the Amsoil filter. I thought I did a good job of removing the excess oil, but in the last 10 K miles, some has apparently wicked out.

Assuming I can find a Torx driver with the hole up the center to remove the sensor, what is the proper way to clean it?

I'm off to NAPA to see about a driver and a new PAPER filter, will look for look for suggestions here before trying anything.

Thanks.

[george morrison]

MAF contamination can be/is a problem with oiled air filter elements. Our engines consume huge amounts of high velocity air and will bring along anything that is not well attached, including oil. http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic;f=25;t=000141;p=4

The above site is interesting in that at a recent VW TDI (diesel) dyno check, the car with the highest horsepower/torque was paper/oem air filter equipped...

George Morrison, STLE CLS
(I have no affiliation with AC and obviously none with K&N or Amsoil. :)

[Kennedy]

If you find it necessary to clean the sensor, you can leave it in the box lid, and just pop the lid off. A quick spray of Lectra-motive will take care of you.

A little film on the sensor is not necessarily the end of the world so long as the values are not altered. Generally, if altered, it will set a code.

I will continue to use my oiled foam air filter for it's improved filtering capability.

[LarryM]

kennedy, what is Lectra-motive? Who might carry such a product? What is it's composition?

The screws holding ths MAF sensor in place are Torx "tamper-proof" # 20. NAPA did not carry that particular size. I had to go to my industrial nut & bolt house for the bit and paid $7.50 plus tax for it!

[IndigoDually]

I just used a small flat head screwdriver that jammed in enough to grab. The senson screws are not verytight and easily came out. I dipped it in denatured alcoho and swished it around. I let it air dry and put it back in no problems. You need to use 100% alcohol not the 2% rubbing or it deposits more than you are trying to remove.

John

[LarryM]

IndigoDually:

I could have got the screws out without a $7.50 tool, but I did not want to leave telltale marks so the dealer idiots could deny warranty coverage later.

I just poured denatured alchol over the thing, took three flushes to get rid of all the oil film.

Close inspection showed me a lot. The sensor element on the side of the venturi structure appears to ba a garden variety semi-conductor thermistor. I assume this is the IAT. This thermistor is glass encapsulated and probably immune to most anything short of physical damage.

Placed in the venturi are what appear to be two wire wound resistors. The wire is open to the air and very fine diameter and closely space. These devices appear to be very delicate. I would not worry much about a fine oil film on them except that ALL filters pass some dirt. Oil + dirt = trouble.

Assuming there is no additional circuitry in the housing, two of the five wires should be for the IAT. That leaves three for the other two sensors telling me that they are connected as a differential pair. A common arrangement, I think I first saw it used in a Carl & Jerry column in Popular Electronics about 45 years ago!

If this assumption is correct, it would be an easy thing to shunt the reference side of the sensor pair with a fixed resistor and fool the computer into thinking there is more air flow than there really is. Of course, there would be a finite limit to the ammount you could fudge it, because the computer would catch on when it does it's boot up calibrations.

At any rate, it's fun to imagine a 25 cent cup of "juice"!

[Kennedy]

CRC makes Lectra motive.

LPS makes and electrical parts cleaner too. These are in spray bomb form, and will not hurt the components. Truth be told, I've shot them with Brakleen or carb spray, but don't hold me accountble if it hurts something. The way I look at it, it has to ba able to withstand a quite a bit IE: evaporative emmisions etc...

[JimErickson]

Just picked up some Lectra-Motive made by CRC.

I was about to spray my sensor and decided to read the label smile.gif

It specifically says not to use on Rubber or Plastic.

Am I going to melt the plastic MAF mount?

Thanx
Jim

[ 03-21-2003: Message edited by: JimErickson ]</p>

[Kennedy]

That's a darn good question!

Try spraying n a non sensitive area first and see if there is a reaction.