GolfGTIforum.co.uk
Model specific boards => Golf mk4 => Golf mk4 how to guides + info => Topic started by: richw911 on 13 October 2008, 23:47
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A very common fault on the MK4 golf is the maf sensor can fail.
Fault symptoms include:
Rough idle
Bad MPG
Power loss
Flat spot
Engine stalls
Do a fault scan using vag com or a fault code reader to see if you get any codes.
**Note you will NOT always get a fault code with a faulty MAF!!!**
If you dont get a fault code try unplugging the MAF to see if it runs better - if it does the MAF will be faulty.
DONT BUY CHEAP!!
With MAFs i would ALWAYS say pay the few quid extra and go to the dealers.
You can get most things from GSF/eurocarparts ect but NOT MAFs or coilpacks
Lots of people have had so much trouble with cheap nasty MAFs from eurocarparts, and wasted lots of money on other things -thay assumed because the MAF was new it was fine - Not the case!!
NEVER buy cheap with these its really not worth the hassle! :wink:
Air Volume Meter (MAF) Part numbers for each engine:
06A 906 461 L - AUM, ARX, AUQ
06A 906 461 A - AQY, APK, AZH, AEG AGN
06A 906 461 G - AZJ
037 906 461 C - AGU
06A 906 461 C - AGR, AHF, ALH, ASV, ATD
074 906 461 B - ASZ .
This may be of help aswell http://www.passatplus.de/lmm/index.htm
NB - All these MAFs are now exchange items from dealers. Add X to the end of the part number above for the exchange unit part number. Price on exchange is circa £76.50 excluding a refundable deposit conditional on the old MAF being returned to the dealer.
For those who don't know, the MAF (mass air flow) sensor measures the mass of air entering the engine to control the air/fuel ratio. The sensor is incorporated into the intake system after the air filter. Bosch uses a hot-wire MAF sensor, which is a platinum wire heated to 212*F (some say 180*F) above ambient temperature. As air is sucked into the engine past the wire, it has a cooling effect that's offset by an increase in voltage to the sensor to maintain the 212*F. The engine management system then determines how long to keep the fuel injectors open. Upon shutdown, Bosch MAF sensors briefly heat the wire to 1,000*C to burn off any contaminants.
It can be found on your air box and looks like this:
(http://i163.photobucket.com/albums/t318/richw911/forum/MAFpic1.jpg)
To Remove your MAF :
Step 1:
Depending on your set-up, you may find it easier to take the air-box out as well.
You will have 2 philips-head screws to the rear of the air-box (Note: Thay dont come out completely).
These along with the tabs hold the cover down.
(http://i163.photobucket.com/albums/t318/richw911/forum/mafpic2.jpg)
Step 2:
Gently press tab to unlock and pull plug off MAF. Tuck up and out of way.
(http://i163.photobucket.com/albums/t318/richw911/forum/mafpic3.jpg)
Step 3:
There are two (each side) philips head screws that hold the MAF to the air-box. Remove these. Unlike the air-box, these come out completely.
Since they can be a bit of a pain, I recommend putting a rag under your work area. If you do drop one they will fall here rather than into the engine area.
(http://i163.photobucket.com/albums/t318/richw911/forum/mafpic4.jpg)
Step 4:
Loosen clamp around neck of TIP (Turbo Inlet Pipe). Just push this down the pipe and out of the way.
You may have one of those self squeeze clamps. They are can be a bit of a nightmare. You will need a very large set of arc joint pliers.
Step 5:
Slowly pull MAF out of air-box and then out of the TIP.
You just have to wiggle it out. Be very careful not to damage anything!
The writer of this guide and GolfGTI.co.uk accept no responsibility of damage to your car when using this guide. Use at your own risk.
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hi not being daft but vag com ?????????????????????????
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hi not being daft but vag com ?????????????????????????
See here :
http://www.vagcom.co.uk/
http://www.golfgtiforum.co.uk/index.php?board=73.0 :wink:
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if im getting this reading does it mean my MAF is knackered?
(http://i220.photobucket.com/albums/dd256/tweeter_box/vag.jpg)
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looking at that there is nothing to mention the MAF!
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looking at that there is nothing to mention the MAF!
at a guess what would you say it was?
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looking at that there is nothing to mention the MAF!
at a guess what would you say it was?
not a clue in all honesty - not up to speed on the 1.6
all that screen shows is the readiness of certain components but is useless if your car doesn't have them!
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looking at that there is nothing to mention the MAF!
at a guess what would you say it was?
not a clue in all honesty - not up to speed on the 1.6
all that screen shows is the readiness of certain components but is useless if your car doesn't have them!
but when i did a scan 5 mins before i took the pic they all said passed, then i cleared the fault code i had and the screen changed to this, now my engine lights on aagain :sad:
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Been to the local VW stealer today and they quoted me £89.01 for a new MAF on exchange.
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Can ya drive without the MAF plugged in ? :rolleyes:
Just till I have enough money for one
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You can but its recommended that you replace it a.s.a.p
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Bought Bosch one at Euro car parts today.
£90 then you get a £25 trade in, so £65.
Sorted :wink:
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Bought Bosch one at Euro car parts today.
£90 then you get a £25 trade in, so £65.
Sorted :wink:
Good price that!
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Thanks for all the info. I was losing power at about 2000 rpm, although it didn't run too rough or stall. Changed the MAF following the easy guide, and now it's working well! Got a genuine Bosch for £54 + vat from GSF the same as somebody else in this thread.
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Thanks for all the info. I was losing power at about 2000 rpm, although it didn't run too rough or stall. Changed the MAF following the easy guide, and now it's working well! Got a genuine Bosch for £54 + vat from GSF the same as somebody else in this thread.
Great stuff :afro:
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i unplegged my maf today and drove it , it was exactly the same
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Does the non-turbo have a MAF? I notice in the original post there is no mention of the AGN engine.
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All modern cars have a MAF.
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ok, could someone add the AGN engine to the first post then?
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ok, could someone add the AGN engine to the first post then?
Indeed - done :wink:
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I've been getting a rough idle too and sometime it cuts out a few seconds after turning on first thing.
I've just disconnected the MAF by disconnecting the MAF plug and im going to drive it home to see if there is any difference.
Can you let me know if this is enough for a test, that is, to disconnect the MAF plug, i assume i dont have to remove the MAF sensor as well as it wont now be feeding anything back.
I also presume its quite safe to drive it home? :wink:
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Fine to disconnect
How far is home though as it should only be for very short trips i.e I'd say less than 2 miles
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Fine to disconnect
How far is home though as it should only be for very short trips i.e I'd say less than 2 miles
About 20 miles!
Maybe i'll stick it back on and go for a drive when i get home.
Can i ask, if the MAF is faulty would i notice a difference or the same issues?
I ask as if the MAF wasn't faulty i would expect disconnecting it by removing the MAF plug to decrease the performance of the engine not increase it. If it was to stay the same then i would have thought the MAF must be faulty because its running the same disconnected as it was connected.
However i see other posts on here saying it runs better disconnected.
Any tips on expectations?
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Yeah don't drive the 20 miles home lol
If the idle improves and it drives better with it DISCONNECTED its normally a sign the MAF is fubared
What's the mileage of the car?
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Thanks for the feedback - much appreciated.
It has about 100k on the clock now - 1.8 GTI non turbo (for my sins)
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Thanks for the feedback - much appreciated.
It has about 100k on the clock now - 1.8 GTI non turbo (for my sins)
Could well be due replacement really :undecided:
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Thanks for the feedback - much appreciated.
It has about 100k on the clock now - 1.8 GTI non turbo (for my sins)
Could well be due replacement really :undecided:
:grin: Unfortunately i don't have cash to splash on theories.. Although this is looking like a good bet.
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Well, i drove it a bit last night and i have some conflicting results.
When its off the idle seems better but there is a big dip in power around 2000revs, soooo im not sure?
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do have to have the maf connected all the time !! what happens if you drive without it connected !! :shocked:
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Hi everyone, i have in my Gti MkIV K04-02X turbo kit, 370cc inj, Revo software, Edelbrock fpc, FMIC, 3" inlet, 3" intake and oem maf sensor (AGU code maf sensor) with 3" maf air duct...my problem began when I push full throttle with very low fuel level and a injection misfire began intermitently...I already scaned it I I found MAF sensor malfunction...I replace it for another one.::at first the problem was solved but then it started again even with high leve fuel...Any Ideas or suggestions PLEASE! (I also have and extra fuel pump directly to the fuel rail 3BAR at engine Iddle)
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Hi. I recently bought a 03 gti 180bhp 6 speed and am wondering if it has a faulty MAF. There is an exhaust light on the dash the PO said was from an aftermarket hose that doesn't have a sensor but the traction control light is also on. My friend who specialises in German cars says he thinks the MAF may be faulty but he hasn't had the time to have a good look yet. The other day I had it at 40mpg according to the dash so mileage seems ok, the idle is smooth and it doesn't stall on it own. Because the TC isn't working it spins the wheels up in first when I put my foot down, even if I'm already moving, and it even gives a little spin and I change into second so I guess power isn't down but after second the car does feel a bit slow but I have no idea if I just have too high expectations. The other day I went to an abandoned airfield and put my foot to the floor. I got it up to 125 in 4th at around 4.5k and the revs were barely climbing anymore. I would need to get it on a motorway to get anywhere near top speed I reckon. Is this normal or could this be low power/a flat spot? This is my second car so I have hardly anything to compare to other than my motorbikes which are obviously a lot faster so I really don't know if im expecting too much or if there could be a problem??
Edit: also I just drove the car home and gave it a good thrash and when I got to some lights and put the clutch in the revs hesitated before they dropped. I gave it some throttle again and they stayed up for a second before they dropped again. First time it's done that and I'm fairly sure that's not normal. Maybe a sign it's running a bit rich sometimes??
Any ideas appreciated
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I would get it scanned pronto. and go from there. :smiley:
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I got it scanned. My mate wasn't happy with the MAF so I changed that today. The traction control now works but im still not 100% on the amount of power. Going to get the exhaust warning light sorted first and then see what's what. Definitely a step in the right direction though :-)