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Model specific boards => Golf mk4 => Topic started by: Grand Master Patch on 11 April 2009, 22:08

Title: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:08
Due to a conversation with a good friend today,the question was raised what kills a maf?

Anyone?
Title: Re: What kills a maf?
Post by: richw911 on 11 April 2009, 22:11
Crap aftermarket intakes, Or just wear and tear.

Some people change them every 2 years as a service item.
Title: Re: What kills a maf?
Post by: jonnyturbo on 11 April 2009, 22:12
yup agreed aftermarket ones are rooooobish
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:24
We came to the conclusion that it has nothing to do with what air filter you have.

All 1.8t's have a breather hose at the top of the engine,through this comes oil vapour.This vapour is recirculated back into the intake pipe.What sits right next to this pipe? The Maf.When the dv dumps air back into the intake pipe it's rich in oil vapour,and is passing this vapour back through the maf.Think carbonio woosh

What are your views on this theory?
Title: Re: What kills a maf?
Post by: richw911 on 11 April 2009, 22:27
We came to the conclusion that it has nothing to do with what air filter you have.

All 1.8t's have a breather hose at the top of the engine,through this comes oil vapour.This vapour is recirculated back into the intake pipe.What sits right next to this pipe? The Maf.When the dv dumps air back into the intake pipe it's rich in oil vapour,and is passing this vapour back through the maf.Think carbonio woosh

What are your views on this theory?

Yeah i was thinking more along the lines that some intakes lets loads of crap in which a normal filter would stop  :undecided:
Title: Re: What kills a maf?
Post by: jonnyturbo on 11 April 2009, 22:28
yup i must agree stick with the smoothed box and get a pipercross Air intake in the wing = risk of water suckage lmao SUCKAGE
Title: Re: What kills a maf?
Post by: Ivor Mk4 Turbo on 11 April 2009, 22:28
We came to the conclusion that it has nothing to do with what air filter you have.

All 1.8t's have a breather hose at the top of the engine,through this comes oil vapour.This vapour is recirculated back into the intake pipe.What sits right next to this pipe? The Maf.When the dv dumps air back into the intake pipe it's rich in oil vapour,and is passing this vapour back through the maf.Think carbonio woosh

What are your views on this theory?


I don't think air/vapour can get pushed back as far as the MAF as the engine is constantly sucking the air in at a greater velocity in the opposite direction??!! :undecided:
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:30
The oil that kills the maf isn't coming from the air filter,it's being blown back through from the other side. :sad:
Title: Re: What kills a maf?
Post by: jonnyturbo on 11 April 2009, 22:31
ah you mean like K n N filters ?
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:33
We came to the conclusion that it has nothing to do with what air filter you have.

All 1.8t's have a breather hose at the top of the engine,through this comes oil vapour.This vapour is recirculated back into the intake pipe.What sits right next to this pipe? The Maf.When the dv dumps air back into the intake pipe it's rich in oil vapour,and is passing this vapour back through the maf.Think carbonio woosh

What are your views on this theory?


I don't think air/vapour can get pushed back as far as the MAF as the engine is constantly sucking the air in at a greater velocity in the opposite direction??!! :undecided:

In reply to that,where is the sound of the dv echoed when running a carbonio? Inside the carbon fibre pipe,this pipe is on the other side of the maf :shocked:

Title: Re: What kills a maf?
Post by: Ivor Mk4 Turbo on 11 April 2009, 22:33
The oil that kills the maf isn't coming from the air filter,it's being blown back through from the other side. :sad:


So where does the theory/rumour of oily K&N's ruining the MAF's come from then?? :undecided:
Title: Re: What kills a maf?
Post by: jonnyturbo on 11 April 2009, 22:34
hmm thats a gudd in
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:34
ah you mean like K n N filters ?

No,the oil vapour is still blown back through the maf even on the std paper filter.
Title: Re: What kills a maf?
Post by: jonnyturbo on 11 April 2009, 22:34
i have just heard before K n N are oil based
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:36
The oil that kills the maf isn't coming from the air filter,it's being blown back through from the other side. :sad:


So where does the theory/rumour of oily K&N's ruining the MAF's come from then?? :undecided:

Urban myth,they wouldn't sell them if they killed mafs.Speak to any tunning supplier and they will tell you the same.

Title: Re: What kills a maf?
Post by: Ivor Mk4 Turbo on 11 April 2009, 22:37
We came to the conclusion that it has nothing to do with what air filter you have.

All 1.8t's have a breather hose at the top of the engine,through this comes oil vapour.This vapour is recirculated back into the intake pipe.What sits right next to this pipe? The Maf.When the dv dumps air back into the intake pipe it's rich in oil vapour,and is passing this vapour back through the maf.Think carbonio woosh

What are your views on this theory?


I don't think air/vapour can get pushed back as far as the MAF as the engine is constantly sucking the air in at a greater velocity in the opposite direction??!! :undecided:

In reply to that,where is the sound of the dv echoed when running a carbonio? Inside the carbon fibre pipe,this pipe is on the other side of the maf :shocked:




(http://i42.photobucket.com/albums/e345/ivormk4/Smileys/dunno.gif)  (http://i42.photobucket.com/albums/e345/ivormk4/Smileys/confused.gif)

Where's Topher when you need him??!! :D
Title: Re: What kills a maf?
Post by: Ivor Mk4 Turbo on 11 April 2009, 22:38
The oil that kills the maf isn't coming from the air filter,it's being blown back through from the other side. :sad:


So where does the theory/rumour of oily K&N's ruining the MAF's come from then?? :undecided:

Urban myth,they wouldn't sell them if they killed mafs.Speak to any tunning supplier and they will tell you the same.




Jabbasport recommend a paper filter, but then again, they supply their own brand, though.
Title: Re: What kills a maf?
Post by: topher on 11 April 2009, 22:41
Where's Topher when you need him??!! :D

Sitting here chuckling to myself. Oil vapour blowing OUT of an intake, please :grin:
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:41
What's worse is that the oil vapour being sent back into your turbo actually reduces the octane of you fuel :sad:
Not only does it kill your maf,it reduces pefromance aswell...
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:43
Where's Topher when you need him??!! :D

Sitting here chuckling to myself. Oil vapour blowing OUT of an intake, please :grin:
Care to explain how std cars,still need replacement mafs?
Title: Re: What kills a maf?
Post by: Dubbz on 11 April 2009, 22:43
Have a smell of a maf, mine smelt sooty.  :sick:
Title: Re: What kills a maf?
Post by: jonnyturbo on 11 April 2009, 22:45
lmao dubbz will put it on my jobs to do list LMAO
Title: Re: What kills a maf?
Post by: topher on 11 April 2009, 22:46
Care to explain how std cars,still need replacement mafs?

Gremlins, magical fairies, or parts not fit for purpose in the first place.
Title: Re: What kills a maf?
Post by: Dubbz on 11 April 2009, 22:47
lmao dubbz will put it on my jobs to do list LMAO

:afro:  :grin:
roll a twenty up while ya in there.  :evil:
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 22:48
The solution?
Oil catch can,read up about it :laugh:

Title: Re: What kills a maf?
Post by: Dubbz on 11 April 2009, 22:52
The solution?
Oil catch can,read up about it :laugh:



Is that the same as a breather pipe going back in to the sump?  :undecided:
Title: Re: What kills a maf?
Post by: Grand Master Patch on 11 April 2009, 23:10
The solution?
Oil catch can,read up about it :laugh:



Is that the same as a breather pipe going back in to the sump?  :undecided:
Not even close....
Title: Re: What kills a maf?
Post by: Wazzzer on 12 April 2009, 10:59
I think it's just the fact it's super heated on shut down everytime, metal can't cope with that constantly so gives up. Also if it has some crap on it when it does this it could react and burn the sensor more

I've had a K&N on mine for over a year now and I've never had to replace the MAF so I don't believe the hype about them
Title: Re: What kills a maf?
Post by: RTechUK on 12 April 2009, 12:30

IMO its not 100% going to be down to the engine oil vapor,  I cannot see how oil can get blown back on to the maf element? Look at a 1.8t DBW MAF and you will see what I mean.  Plus when you lift off from under load the air is pulled towards the turbo , because the turbo is still spooling and pulling air in at a lowe volume. If  the DV is fecked the turbo would stall and the air would come come back toward the MAF.

 If the vapour was comming back in to the maf the maf would be wet with oil like the inside of a IC pipe?  It is down to ware and tear, constant heating and cooling of the elements, vibration, water vapour, dust, air flow errosion.
Cheap cone filters kill MAFs at a quicker rate due to added, vibrations, extra heat and larger dust particals being allowed it. Plus Oiled filters do cause issues, look inside a MAF from a car running a oiled filter and it will look like it have a sticky texture and dust all over the internal surface. 

Plus MAF are degined not to last forever if you know what I mean. :wink:

On a car with poor crank/cam case breathing the oil vaspour can reduce the the power by a very small amount, fitting a catch tank can over come this. My calibra turbo had to have a catch tank fitted to stop it smoking due to the poor oem breather set up,When I went around a right left hand bend my induction took a nice gulp of oil which caused a flat spot..   The OEM breather set up on the 1.8t aint too bad so you should not see a gain in performance by fitting a catch tank.

Nick
Title: Re: What kills a maf?
Post by: Grand Master Patch on 12 April 2009, 13:03
When a carbonio cai,or any after market cai is fitted to a 1.8t,am i right in saying the sound of the dv is louder due to it echoing inside the pipe?
Title: Re: What kills a maf?
Post by: RTechUK on 12 April 2009, 13:55
When a carbonio cai,or any after market cai is fitted to a 1.8t,am i right in saying the sound of the dv is louder due to it echoing inside the pipe?

The release of air sound is louder when a solid pipe is fitted to the intake. It echos louder, Plus you also get a louder sound when the turbo is spooling up,   If your DV is not working right you will also hear the stalling of the turbo as the air makes it way back over the turbo vanes, some people call this noise wastegate chatter when its infact the air being chopped up as it slows the turbo down.   The idea of the dv is to  keep a vaccume in the turbo outlet side and a slight positive feed into to the turbo, this allows the turbo to substain highe rpms which reduce the turbo lag. 
 Yes you can hear the echo luder from an induction kit but its not an indecation of all the air comming back out of the air box,  It it was comming out of the air box the top if the nice yellow oem air filter would be black with the oil vapour after 5k miles, would it not? 

Maybe if your DV is not working right you will get oil vapour back in to the air box which could result in a reduced life span for the MAF?

Nick
Title: Re: What kills a maf?
Post by: Grand Master Patch on 12 April 2009, 17:08
So it's not all down to what filter you use,it's a combination of many factors. :smiley:
Title: Re: What kills a maf?
Post by: RTechUK on 12 April 2009, 22:04
So it's not all down to what filter you use,it's a combination of many factors. :smiley:

Your right on the money there mate :wink:

 I have never seen inside a vag maf unit so I might open one up and see what is in there to go wrong.
My Calibra turbo hot wire MAF is always brought back to life with a quick spray of carb cleaner, I use a happy shopper cone filter which quickley sh@ts up the maf.

Did you do the smoothed air box mod in the end?

Nick

Title: Re: What kills a maf?
Post by: Grand Master Patch on 12 April 2009, 22:10
I've still not fitted the std air box,i've still got the K&N cone filter on(that came on the car when i bought it),nothing wrong with my maf either.

Just had a mad theory about mafs :grin:
Title: Re: What kills a maf?
Post by: RTechUK on 12 April 2009, 22:29
I've still not fitted the std air box,i've still got the K&N cone filter on(that came on the car when i bought it),nothing wrong with my maf either.

Just had a mad theory about mafs :grin:

I have an old air box from a 2000 ARZ if you want it?

Nick
Title: Re: What kills a maf?
Post by: Grand Master Patch on 12 April 2009, 22:33
I've got an airbox to fit,just not fitted it yet :embarassed:
Title: Re: What kills a maf?
Post by: RnP on 12 April 2009, 22:52

IMO its not 100% going to be down to the engine oil vapor,  I cannot see how oil can get blown back on to the maf element? Look at a 1.8t DBW MAF and you will see what I mean.  Plus when you lift off from under load the air is pulled towards the turbo , because the turbo is still spooling and pulling air in at a lowe volume. If  the DV is fecked the turbo would stall and the air would come come back toward the MAF.

 If the vapour was comming back in to the maf the maf would be wet with oil like the inside of a IC pipe?  It is down to ware and tear, constant heating and cooling of the elements, vibration, water vapour, dust, air flow errosion.
Cheap cone filters kill MAFs at a quicker rate due to added, vibrations, extra heat and larger dust particals being allowed it. Plus Oiled filters do cause issues, look inside a MAF from a car running a oiled filter and it will look like it have a sticky texture and dust all over the internal surface. 

Plus MAF are degined not to last forever if you know what I mean. :wink:

On a car with poor crank/cam case breathing the oil vaspour can reduce the the power by a very small amount, fitting a catch tank can over come this. My calibra turbo had to have a catch tank fitted to stop it smoking due to the poor oem breather set up,When I went around a right left hand bend my induction took a nice gulp of oil which caused a flat spot..   The OEM breather set up on the 1.8t aint too bad so you should not see a gain in performance by fitting a catch tank.

Nick


excellent read Nick hit the nail on the head there,

i have had experiences in the past where only a blow through set-up or a maf less ecu was optional, ( on big hp cars ) the standard air box will do me for a while,

what i want to know is do people with the k & n filters and alike use to clean the filter with ?
Title: Re: What kills a maf?
Post by: tariqb on 13 April 2009, 00:29
the maf's killing me at the moment - £20 for 100 miles  - !!!
Title: Re: What kills a maf?
Post by: Wazzzer on 13 April 2009, 09:27
I hoover mine out every now and then but I never re-oil it, it seems to have enough on in the element as it is