MAF Sensor Cleaning

[sperold]

I took the MAF sensor off the flex tube assembly to clean it (with a sensor safe cleaner from CSC). It had 4 torx-like fasteners with pins in the center that needed special sockets to get them off.
The surface to surface plate connection has a lot of dusty looking stuff (like aluminum oxidation) and I am wondering what to do with this. Should I clean it off, or should I apply some dielectric grease to make a great connection, or what ever?
This thing seems to play a big role in the induction system so I want it to be correct.
Also, this little sensor sit in a small hole above the full size tube. Should I get lots of cleaner in this little hole and see where it comes out. And, while I have the cleaner out, how does that mesh screen prefer to be cleaned.... do I use the same cleaner?
I have a chronic lean mixture situation, and I am hoping a good cleaning of this part will help.

 

[gmorrell]

I just spray the cleaner at the two sensor coils on the ends of the little wire posts. Don't brush or otherwise touch the coils, as they're very fragile.

Don't apply any dielectric grease between the electronics body and the MAF body, just wipe off the ****, or use a soft bristle brush, staying away from the sensing coils. The MAF electronics package can dissipate some heat, and it dumps the heat into the heat spreader plate on the bottom of the electronics package, and some of that heat conducts into the Aluminum MAF housing.

 

[sperold]

Thanks for the advice.
I am trying to nurse this car through an emissions test and I have 2 fails under my belt to date.
I am getting a pass on everything except the NO (ppm). I am reading 493 and I need to get under 435, so that is why I am concentrating on the MAF system.

 

[93rev2sev]

A couple of things...

When you say you took the MAF sensor off...I think you mean to say that you took the MAF sensor HOUSING off...not the sensor. The sensor is screwed into the housing using only 2 small security torx bits. You need to remove the sensor from the housing (not the housing from the flextube) in order to clean the small filaments properly. Lift the sensor straight out of the housing or you may damage the filaments (think Milton Bradley's "Operation").

Regarding the rest of the housing, once you've removed the MAF sensor, you can clean it with solvent and a brush, or whatever you choose. There's no need to get crazy on the inside of this housing. Just rinse it out with brake cleaner and make the outside as pretty as you want. Remember, all the air your engine uses goes through this housing, so let it air dry, you don't want lint or paper towel fuzzys or cotton from a rag getting stuck in there. If you paint the housing, make sure you mask off all inlets and all mating surfaces.

The MAF sensor has a metal base that can get aluminum oxide corrosion (or perhaps it's heatsink paste from the factory). If you try to clean that off you will probably damage the sensors' filaments in the process. They are very delicate and should only be touchd by a stream of MAF sensor cleaner.

A light coating of dielectric grease on the mating surfaces will help keep corrosion from coming back immediately but there's no electrical need for grease other than on the connector (for the same corrosion protection).

 

[JRA2000TL]

What I did was unscrew the torx bits, carefully pulled up on the MAF unit/housing (like Tom's Operation example--very carefully). I held it up, sprayed the coils/filaments of the sensor with the MAF cleaner (yes use the straw). Re-installed just as carefully as I removed it. Pretty easy process. The filaments are the most sensative part, so don't ruin those. It should help with your idle some.

 

[frosho]

I'd suggest replacing those security Torx screws with something easier to use while you're working on it. The Torx ones are just a PITA, especially if there's corrosion on them. I replaced mine with some socket head cap screws, M4 x 16mm long. The stock screws are 20mm long, but I think the shorter length screws are actually superior (not to mention a lot easier to find). They fully engage the threads in the MAF housing, but they don't stick out on the bottom side like the stock ones do. This should help prevent corrosion from building up on the ends of the screws, which was a problem for me. I snapped a couple of the stock ones because of it.

 

[itwonder]

I'd clean off the white powdery stuff with the MAF cleaner. It is probably aluminum oxide corrosion as you suspect.