PDA

View Full Version : MAF Sensor - Oil Contamination



Billy T
06-18-2003, 19:32
My MAF Has already been replaced and it was suggested that I remove the K&N and reinstall the factory paper element. This is a similar problem that we had with the 454 powered pickups some time ago. The K&N filter was out of the box so I had not had the oportunity to clean it in which over-oiling is a possibility. I have been using K&N's since the 70's and this is the first issue I have had to deal with. Anyone else with a similar dilima?

Billy T

:eek: :eek: :eek: :eek:

HD-Nate
06-18-2003, 21:53
I have not but have known others that have in the Corvette world, high speeds=high pressure into air cleaner.

The way I avoid this is to have 2 K&N's or keep your paper filter. I clean and oil my K&N then let it hang at least overnight and use the spare or papaer filter for a day or two. Any excess drains off.

Raptorrider2001
06-19-2003, 10:47
How does it act when you get to much oil on the K&N or if the oil messes up the MAS? I recently cleaned and reoiled mine and it seems as if my mileage has dropped. Power seems ok and I installed a new fuel filter at the same time. Thanks :confused:

hoot
06-19-2003, 10:58
It's possible that the re-oiled filter restricts a bit more for a while untill the oil gets dispersed into the gauze.

Billy T
06-22-2003, 21:30
The oil gets picked up by the airflow and some ends up on the wire inside the MAF. It begins setting codes in the PCM but will not trip an MJIL until complete failure then it loses most power. None of my customers have reported a problem to me, and I really don't want to continue running the OEM paper.

RWA II
07-07-2003, 23:54
Just my thoughts on the MAF. I took mine out today to give it a look see, and I am pretty sure that the unit is just two hot wire anemometers. One of them runs parallel to the flow and the other perpendicular to account for eddie currents along the side of the casing. The general construction of these devices invloves a tungsten or platinum wire that uses a bridge circuit to keep them at a prescribed temperature. They usually operate around 200 C, but that is just from experience. If the thermistor between the wires gets dirty, the heat transfer coefficient can be lowered for a typical cylinder in cross flow. Basiclly the device figures out incoming air speed on how much current is required to keep the thermistor at operating temp, and if the wire is dirty then your computer is getting the wrong air speed. If it does not understand what is going on, it may not be supplying enough current or it could be supplying too much and then failure...If it were mine and I thought it was dirty, I would take it out and swish it around in some lab grade Isopropyl (not the 70% crap at Wallgreens), let it dry real well (only wash the thermistor and wire section not the electronics) and pop it back in.


Just my 2 cents,
RWA

sonofagun
07-09-2003, 15:34
exactly what RWA said, especially the part about the alcohol bath. Your dealer will clean it for about $80.00 or suggest you need a new one for more $$$. Doesn't hurt to clean it from time to time but be REAL careful with the unit and don't mess up the wires.

Bob

HD-Nate
07-09-2003, 15:43
...If it were mine and I thought it was dirty, I would take it out and swish it around in some lab grade Isopropyl (not the 70% crap at Wallgreens), let it dry real well (only wash the thermistor and wire section not the electronics) and pop it back in.
RWA [/QB]Good advice but I checked in the medicine cabinet and sure enough, we have the 70% Wallgreen crap :rolleyes:

SO......how does the average Joe get some "lab grade Isopropyl :confused:

TBC
07-09-2003, 18:17
I have the K&N filter charger kit. Every time I drive from Amarillo, TX back to Ft Worth the SES light comes on, usually when I make a stop and shut off the engine. It will stay on until I return to Amarillo. There is 3000 ft altitude diff and that seems to be the factor. When the light goes off after a few starts in Amarillo it stays off although this last time it came back on for a short time once and then went off again. The truck runs perfect light on or off. Would just like to know why it is doing this. It is going to the dealer soon for a code check but somehow I doubt that one has set.

Tom

et
07-10-2003, 02:00
HD-Nate,

Check this thread for further information on cleaning MAF Sensors:
http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=005698#000005

I still recommend pure grain alcohol as it has so many other uses. This week I used it to prep both surfaces prior to finally relocating my window visors after installing my TTT mirrors back in March. The 3M double sided tape never has come off after using it.

It's use has caused some comments when I was sitting on the ground with a half gallon of Everclear next to me while installing trim to my Airstream Trailer. I reassured my neighbor that I was only using it to steady my hand.

a64pilot
07-10-2003, 06:42
TBC,
I'll bet it is setting a code. I forget the number but I think it's P0101 IIRC, MAF sensor performance I think it is called. At least that is the one mine was setting. I would get the light when there was fog or rain sometimes and the light would clear (after several starts), but the code was still in the computer. BTW the number of times the code has been set is in there too.

HD-Nate
07-10-2003, 08:06
I still recommend pure grain alcohol as it has so many other uses.........
It's use has caused some comments when I was sitting on the ground with a half gallon of Everclear next to me while installing trim to my Airstream Trailer. I reassured my neighbor that I was only using it to steady my hand. [/QB]:D Good Point!

Thanks for the tips.