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MAF cleaner. 3rd gen V6/ EVO

gvr4ever

Well-known member
Joined
Aug 6, 2002
Messages
6,195
Location
central Indiana
Before I stored my car for the winter, I filled it up with gas and wanted to give her one last send, and she fell on her face under boost. Revved fine, ran fine, just started burbling under boost, lost power. I spent about three weeks or so doing research on weather or not CRC MAF cleaner was safe or not. Found a number of people who used it on EVOs on YouTube. While I didn't have an error code on ODB1, I had all the symptoms of a bad MAF. I ended up trying CRC cleaner and cleaned and lubed my K&N filter. I did this while the car was in storage. Fast forward to about a week and a half ago. The car now runs perfectly fine and runs great under boost again. While I haven't given it the full beans under full boost yet. I have turned the boost to high and sent it a little. So far, no issues at all. Still waiting for the tank to get empty to fill with fresh 93. It didn't sit that long, but fuel can loose octane points from sitting. Not sure what the age to octane point is, but I rather be safe than sorry.

*Do at your own risk!

While I don't believe the 3rd gen V6/EVO MAF is Karman Vortex MAF (it looks nothing like the stock MAF) CRC doesn't say not to use on Dodge or Chrysler and I know the same V6 engine was in those cars, with the same MAF.

I was going to put this under the how to section, but I feel it could use some discussion. Hopefully, someone has some insight as to what style of MAF the modern cars have, because too many people scream Karman Vortex, but the stock one didn't have anything in the middle. It's not the same thing.

Oddly, I do seem to be getting better fuel economy.
 

gvr4ever

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Joined
Aug 6, 2002
Messages
6,195
Location
central Indiana
*bump. Does anyone have any insight as to what the more modern MAFs are? Another symptom I had that was a clue was idle seek. I didn't have an idle surge, but it was seeking a little too hight, too low. Since cleaning, it's rock solid again.

This question of Karman Vortex MAF on 3rd gen/EVO MAFs seems to be years old. I'm confused as to why it hasn't been answered yet. I only know that EVO guys have cleared MAF codes cleaning with CRC MAF cleaner succesfully.
 

Dan D

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Joined
Feb 27, 2001
Messages
1,171
Location
Brownsburg, IN
3G / Evo MAFs are Karman Vortex MAFs. Hence the honeycomb. It's needed to "straighten" the air for accurate measurement.
 

gvr4ever

Well-known member
Joined
Aug 6, 2002
Messages
6,195
Location
central Indiana
3G / Evo MAFs are Karman Vortex MAFs. Hence the honeycomb. It's needed to "straighten" the air for accurate measurement.
The honeycombs were meant to create vortexes, not straighten the air. The stock MAF had way deeper honeycombs and a sending and receiver sensor on each side to count the vortexes.. https://www.ebay.com/itm/276302041498?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338678874&toolid=20006&customid=s%3AGS%3Bgc%3A178d50828fe51d8098983545e1934319%3Bpt%3A1%3Bchoc%3A1&customid=s:GS;gc:178d50828fe51d8098983545e1934319;pt:1;choc:2

The modern MAFs look nothing like the original, and while the modern ones do have a screen, it's not as deep and closer to a screen.
 
Last edited:

gvr4ever

Well-known member
Joined
Aug 6, 2002
Messages
6,195
Location
central Indiana
The original MAF had the sensors that couldn't get wet, and it looks like it also had a cardboard/cork looking material. Whatever the modern MAFs are, they don't seem to have the exposed sensors. It has a metal box looking frame, with a center post and what looks to be a resistor. It looks to be all metal and plastic. Either way, CRC cleaner seems to work.

*Still do at your own risk. I was willing to buy another MAF, but chose to spend $20 on attempting to clean it, and it paid off. I only did that after reading many success stories from EVO owners.
 

Dan D

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Joined
Feb 27, 2001
Messages
1,171
Location
Brownsburg, IN
The honeycombs were meant to create vortexes, not straighten the air.
The honeycombs were meant to create vortexes, not straighten the air. The stock MAF had way deeper honeycombs and a sending and receiver sensor on each side to count the vortexes.. https://www.ebay.com/itm/276302041498?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338678874&toolid=20006&customid=s%3AGS%3Bgc%3A178d50828fe51d8098983545e1934319%3Bpt%3A1%3Bchoc%3A1&customid=s:GS;gc:178d50828fe51d8098983545e1934319;pt:1;choc:2

The modern MAFs look nothing like the original, and while the modern ones do have a screen, it's not as deep and closer to a screen.
The honeycomb plus the volute at the inlet are there to create well defined, stable, straight flow lines so that vortice generation is predictable. Vortex creation happens when the air crashes into the "dividers" which are actually the vortex columns responsible for disrupting the flow. If the incident air isn't prepared by honeycomb into a known flow line before hitting the column, then relationship between air mass and countable vortices is no longer valid as they don't occur in a predictable direction, location, or at the expected air velocity.

The resistor looking thing is a thermistor used to measure IATs needed to calculate air mass. They are typically hermetic.
 

gvr4ever

Well-known member
Joined
Aug 6, 2002
Messages
6,195
Location
central Indiana
The honeycomb plus the volute at the inlet are there to create well defined, stable, straight flow lines so that vortice generation is predictable. Vortex creation happens when the air crashes into the "dividers" which are actually the vortex columns responsible for disrupting the flow. If the incident air isn't prepared by honeycomb into a known flow line before hitting the column, then relationship between air mass and countable vortices is no longer valid as they don't occur in a predictable direction, location, or at the expected air velocity.

The resistor looking thing is a thermistor used to measure IATs needed to calculate air mass. They are typically hermetic.
I got my car out of storage today. We hit 62 degrees. I filled it with some fresh 93 and ran WOT on high boost. Car is running perfectly now. The V6/EVO MAF seems to be CRC seems to be safe to clean.

*disclamer. Still do at your own risk. New ones from rock auto or used ones don't break the bank, but be prepared to replace. Myself and what seems to be many EVO owners have had success using CRC MAF cleaner.

For stock MAFs, do NOT use!
 

ggsxkid

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Joined
Dec 15, 2005
Messages
919
Location
La vergne TN/Lake Zurich IL
I may or may not give it a try with my 3g maf. I know for sure that I have start up/idle issues after the car has been warmed up/driven. It usually has a hard time after I come out of the store or get ready to bring it into the garage after a drive.
 

gvr4ever

Well-known member
Joined
Aug 6, 2002
Messages
6,195
Location
central Indiana
I may or may not give it a try with my 3g maf. I know for sure that I have start up/idle issues after the car has been warmed up/driven. It usually has a hard time after I come out of the store or get ready to bring it into the garage after a drive.
Cleaning made my idle rock solid. Like new (stock)
 
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