MAF Cleaning (used to be "Technical Forum")

Joshie

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Is this forum missing?

And who will be the first to post a question about cleaning MAF's or servicing dump valves? /ubbthreads/images/graemlins/grin.gif
 
I 'cleaned' my MAF the other day.

Not a sausage, it was as clean as the driven snow.

So now I have 900ml of Isoprop Alcohol left..... I wonder what it tastes like!

-Dan
 
...............Mass Air Flow (Sensor)

It senses how much air is passing over it and then relays this information to the ECU so that fuel air mixture is regulated.

Dirty MAF's cause turbo lag and general hesitation.

.what an anorak I've become /ubbthreads/images/graemlins/grin.gif
 
Mass Air Flow sensor

A hot wire sensor which monitors the flow of air past by means of the change in temperature the airflow causes (more air cools the hot wire more)

This info is then passed to the ECU which controls the amount of fuel going into the cylinders accordingly.

When they get dirty, they are effectivly insulated from the cold air breeze and hence think less air is going in, and therefore provide less fuel. This makes the car run lean, and hence run slower (which is bad!)

I don't think it is such an issue on the newer cars (like your S3) but certainly on the older motronic S4 (pre 99.5) it was quite common.

I think the newer MAFs (Mass Air Flow Sensors) are self cleaning, in a similar way to self cleaning ovens, they heat up so hot that they burn the dirt off.

Hope this helps.
-Dan
 
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Ok blonde moment.... MAF ???

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Bet you're sorry you asked /ubbthreads/images/graemlins/grin.gif
 
I wouldn't have thought so.

I mean mine was spotless and I have the older version.

To be honest I can't really see how any dirt could get through the airfilter anyway (unless you are running a K&N or similar performance filter)

I reckon most people who clean them are just seeing the dirt from that had collected on the top of the sensor (the bit that is exposed to the world under the bonnet.

Although someone (I think it was Ian) said that they noticed an improvement after cleaning, so who knows?

 
Well if you've got all that alcohol going spare, you can pop over and clean mine if you like /ubbthreads/images/graemlins/wink.gif just round the corner!

Cheers,

Chris.
 
I do....

Or at least I hope so... Feck knows what I cleaned if I don't have one!

I think all 2.7Ts have one (S4, RS4, Allroad turbo & A6)
 
anyone got a Halve Actuated Independent Recycling Yaw MAF? /ubbthreads/images/graemlins/blush.gif

IMHO its a waste of good alcohol, and time and effort cleaning your MAF, anyone disagree?
 
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I do....

Or at least I hope so... Feck knows what I cleaned if I don't have one!

I think all 2.7Ts have one (S4, RS4, Allroad turbo & A6)

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you probably cleaned the MAP lol /ubbthreads/images/graemlins/laugh.gif
 
[ QUOTE ]
anyone got a Halve Actuated Independent Recycling Yaw MAF? /ubbthreads/images/graemlins/blush.gif

IMHO its a waste of good alcohol, and time and effort cleaning your MAF, anyone disagree?

[/ QUOTE ]

Well, to be honest, the first time I cleaned my MA(F)(P) /ubbthreads/images/graemlins/tongue.gif
it was dirty enough to have a visible effect on the alcohol /ubbthreads/images/graemlins/frown.gif I've cleaned it about 3X since putting in my K&N panel, and it's been fairly clean each subsequent time.
 
I think if you're using an oil based fiter like a K&N then there is a requirement to clean the MAF from time to time. The standard cardbourd Audi air filer does not necessitate MAF cleaning.

Anyone agree?
 
Rich,

Me to. K&N panel is sat in a cupboard somewhere. Can anyone think of some alternative uses for it? /ubbthreads/images/graemlins/smile.gif

AL
 
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Rich,

Me to. K&N panel is sat in a cupboard somewhere. Can anyone think of some alternative uses for it? /ubbthreads/images/graemlins/smile.gif

AL

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That answers my question of, are K&N's worth putting in an S3 /ubbthreads/images/graemlins/wink.gif

Jon.
 
Well I'm using a K&N filter because it is claimed to increase airflow and horsepower. Am I right in thinking that these claims are not justified?

Have their been any independent tests apart from the one referred to by K&N?
 
Joshie,

I don't think it would make too much difference on a standard car like mine.

....but then yours is far from standard!! /ubbthreads/images/graemlins/grin.gif

I'd would have thought the standard audi airbox and filter combo were designed with 265bhp in mind, perhaps you could stratch this a bit, but 400hp's worth of air will surely struggle to get through!
 
Well K&N make some ambitious claims about BHP increases on their packaging.

When I had my car dynod at AMD before the mods and running the Abt 310HP chip, a Milltek Cat-back and the APR bi-pipe (as well as the K&N) I was getting 316BHP. The standard ECU produced 272. So that is an increase of 44 BHP for the Abt chip.

Given the Abt's ECU produces 309BHP, this leaves 7HP for all the other mods so possibly the K&N claims are a bit over the top.

The only way to test this would be to put the car on the dyno and run it with or without the K&N and see if there is a difference. The only problem with this suggestion is that the dyno plot is not consistent - so many things to affect the final result.
 
Well, I have had a K&N in my A3 for a bit over a year now, with no problems. While I can't prove any performance increase, I have noticed an improved throttle response, nut the main reason I've kept it, it's reusable /ubbthreads/images/graemlins/smirk.gif
 
True, but the A3 i.8T doesn't have a MAF so you wouldn't have the oil and worries.

I think the 1.8T engines have a pressure sensor, not air mass.
 
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Well, I have had a K&N in my A3 for a bit over a year now, with no problems. While I can't prove any performance increase, I have noticed an improved throttle response, nut the main reason I've kept it, it's reusable /ubbthreads/images/graemlins/smirk.gif

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Another TFB /ubbthreads/images/graemlins/grin.gif

What do you do, wash it in warm soapy water and then apply axle grease /ubbthreads/images/graemlins/laugh.gif

Seriously though - how is it serviced?
 
Joshie,
Actually, K&N have a "Recharger Kit" to clean the filter, it contains cleaner, which you spray on (or soak) the filter with, then you let it dry, and spray on the K&N oil. That's it /ubbthreads/images/graemlins/smirk.gif The only problem with the 1.8T's is if you put too much oil on, you can easily coat your MAF with excess oil, thereby giving it hell. What I do, of course I've only recharged mine 2X now, but I make sure I keep the oil light, and if I do overspray a bit, I blot it with a towel, and pay a bit closer attention to my MAF.
 
Booked the car in for a service and had a chat with the dealer about MAF's, basically he said unless you were running an aftermarket filter or driving in seriously dusty condtions there is NO point in this.
 
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RichA3Turbo said:
So what type of sensor would a 1998 1.8T (a3) have?


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Both. MAF is used for fuelling, MAP is used for boost control.