Clean or replace E39 MAF
Discussion
The Kinkmobile has been running odd over the past few days. The MPG has dropped, and the mpg counter does not match the revs.
I'm suspecting it's the MAF sensor. In addition the car will hit 100k in the new few weeks - so I think that's the normal life of a MAF.
So, considering I've never removed or cleaned it before - would it be worth doing now. Or should I bite the bullet and just replace it (circa £220)?
I'm going to disconnect it, and run the car over the weekend, just to confirm that it is the MAF that's causing the problem. And if so - do I clean it or replace it?
K
I'm suspecting it's the MAF sensor. In addition the car will hit 100k in the new few weeks - so I think that's the normal life of a MAF.
So, considering I've never removed or cleaned it before - would it be worth doing now. Or should I bite the bullet and just replace it (circa £220)?
I'm going to disconnect it, and run the car over the weekend, just to confirm that it is the MAF that's causing the problem. And if so - do I clean it or replace it?
K
Presumably you have done an LH test to see what the fuel rate is? That gives you a good idea of their condition.
The life expentancy is normally around 50k so if they are at 100k they will be well past their best.
Cleaning the MAF is only a tempoary fix, they degrade over time and there is corroision the eye cant see.
Do you know where to get a pair of MAF's? If you do I wont bother posting up any links.
Ta ta, Neil
The life expentancy is normally around 50k so if they are at 100k they will be well past their best.
Cleaning the MAF is only a tempoary fix, they degrade over time and there is corroision the eye cant see.
Do you know where to get a pair of MAF's? If you do I wont bother posting up any links.
Ta ta, Neil
LH = Litres per hour,
///M5s have two Mafs which is what I'm guessing Neil is alluding to.
On the M5 the MAF test is accessed via the OBC as below:
Testing the MAFS :
Follow these instructions, and select the mode for fuel consumption per hour below.
With the engine fully warmed up, drive several WOT (wide open throttle) accelerations. Notice the fuel flow per hour numbers. If everything is ok the numbers should increase continously to about 140 litres per hour at WOT at 7000 RPM. (don´t worry about bouncing into the rev-limiter)
The fuel-flow is directly proportional to the MAF reading reported to the Engine Electronics, so if the
Fuel-flow is correct, the MAFs are most likely correct too.
UNLOCK PROCEDURE:
1) Key to ignition pos 2 (no need to start engine).
2) Fasten the seat belt to get rid of the "Fasten Seat Belt" message.
3) Press the right button on the instrument panel, and hold it until "TEST-NR. 01" comes up (5 to 10 seconds).
4) Press the left button on the instrument panel, and the vehicle id comes up (last 7 digits of VIN).
5) Add up the last 5 digits to get the "unlock code", e.g. the unlock code for "AB12345" would be 15 (1+2+3+4+5).
6) Repeatedly press the right button until "TEST-NR. 19" appears.
7) Press left button -> "LOCK : ON"
8) Repeatedly press left button until "LOCK : xx" appears, where "xx" is your unlock code.
9. Press the right button. All modes are unlocked now.
NAVIGATING BETWEEN TESTS AND PERFORMING THEM:
- Follow steps 1) to 3) of the "UNLOCK PROCEDURE" to enter test mode.
- Use the right button to step from test to test.
- Press the left button to enter a test and cycle between modes within a test.
- Press and hold the right button to exit test mode (turning the key to 0 works as well).
Navigate to test number 4 and select Litres per hour
4) Current fuel consumption in liters per 100 kilometers and in liters per hour. (Maf Test)
///M5s have two Mafs which is what I'm guessing Neil is alluding to.
On the M5 the MAF test is accessed via the OBC as below:
Testing the MAFS :
Follow these instructions, and select the mode for fuel consumption per hour below.
With the engine fully warmed up, drive several WOT (wide open throttle) accelerations. Notice the fuel flow per hour numbers. If everything is ok the numbers should increase continously to about 140 litres per hour at WOT at 7000 RPM. (don´t worry about bouncing into the rev-limiter)
The fuel-flow is directly proportional to the MAF reading reported to the Engine Electronics, so if the
Fuel-flow is correct, the MAFs are most likely correct too.
UNLOCK PROCEDURE:
1) Key to ignition pos 2 (no need to start engine).
2) Fasten the seat belt to get rid of the "Fasten Seat Belt" message.
3) Press the right button on the instrument panel, and hold it until "TEST-NR. 01" comes up (5 to 10 seconds).
4) Press the left button on the instrument panel, and the vehicle id comes up (last 7 digits of VIN).
5) Add up the last 5 digits to get the "unlock code", e.g. the unlock code for "AB12345" would be 15 (1+2+3+4+5).
6) Repeatedly press the right button until "TEST-NR. 19" appears.
7) Press left button -> "LOCK : ON"
8) Repeatedly press left button until "LOCK : xx" appears, where "xx" is your unlock code.
9. Press the right button. All modes are unlocked now.
NAVIGATING BETWEEN TESTS AND PERFORMING THEM:
- Follow steps 1) to 3) of the "UNLOCK PROCEDURE" to enter test mode.
- Use the right button to step from test to test.
- Press the left button to enter a test and cycle between modes within a test.
- Press and hold the right button to exit test mode (turning the key to 0 works as well).
Navigate to test number 4 and select Litres per hour
4) Current fuel consumption in liters per 100 kilometers and in liters per hour. (Maf Test)
Kinky said:
Neil,
As far as the Beemer goes, it would be safe to assume nothing
I thought there was only 1 MAF sensor.
What's the LH test?
I was actually hoping you'd reply ... IIRC, you clean your MAF every 2 months
Oh, As far as the Beemer goes, it would be safe to assume nothing
I thought there was only 1 MAF sensor.
What's the LH test?
I was actually hoping you'd reply ... IIRC, you clean your MAF every 2 months
There are 2 Mass air flow sensors, one for each bank of air intakes.
Yes I do give them a quick blast with electrical contact cleaner every now and them, just to try and keep them tip top.
The LH test is here, follow this proceedure.
http://www.m3torque.co.uk/showthread.php?t=43
You need test 4 and cycle through that test until LH comes up. Its only the scond option. That gives you your flow rate in Liters per hour.
Then when the car is warm redline the car at full throttle and see what the highest number you can achieve is. Anything below 100 or so and your car isnt getting full performance. You should have 120+. The first place to start is the MAF's unless youre getting the EML light or other issues - naturally.
give them a clean no worries but like I say, thats a short term fix. If the car feels better or you get higher numbers after doing so then they are knackered. You will need a T20 security torque to get them out or a bit of patience as the pliers in the tool kit will work to 'mole grip' them undone.
Many many thanks for the inputs .... but I see a fatal flaw in the plan.
1: I only have 1 button on the instrument panel
2: I only have the basic OBC (outside temp, overall MPG and speed, and how far to go until I run out of petrol).
I'll disconnect it anyway in the morning, and have a run around to see if it makes a difference disconnected.
The other option is to buy an M5
1: I only have 1 button on the instrument panel
2: I only have the basic OBC (outside temp, overall MPG and speed, and how far to go until I run out of petrol).
I'll disconnect it anyway in the morning, and have a run around to see if it makes a difference disconnected.
The other option is to buy an M5
Ah, I was writing instructions for the M5, sorry.
I would start by removing your 1 MAF (on the 2.5L) LOL, and giving it a good dousing with Halfords elecrtrical contact cleaner as per the norm. Give it a good shake out and allow to dry for 5 mins and fire her up. If she runs better then replace.
This place may be worth a try.
Emissioncontrols.co.uk
I would start by removing your 1 MAF (on the 2.5L) LOL, and giving it a good dousing with Halfords elecrtrical contact cleaner as per the norm. Give it a good shake out and allow to dry for 5 mins and fire her up. If she runs better then replace.
This place may be worth a try.
Emissioncontrols.co.uk
hi, has to work my speedo same as yours
Menu Sub menu Sample Meaning
Test 1: Vehicle specific data 1.0 12345 VIN
1.1 4812 Body number
6_1.2 834762 Part number of cluster
1.3 010203 Coding/Diagnosis/Bus index
1.4 3495 Manufacturing data (calender week/year
1.5 04_600 Hardware/software number of cluster
3_1.6 415_06 Injection status, number of cylinders, engine factor
Test 2: Cluster system test Activates test for gauge drivers, indicators and LEDs
Test 3: SI data 3.0 1500 Litres
3.1 0 Periodic inspection days (not applicable for US)
Test 4: Fuel consumption data (current) 4.0 0267 26.7 litres/1000km
4.1 0073 7.3 litres/hour
Test 5: Fuel consumed/distance travelled 5.0 0195 19.5 litres/100km
5.1 226 Momentary distance to go (22km)
Test 6: Fuel level sensor input in litres 6.0 237415 Fuel level averaged.
LH sensor input = 23.7 litres - RH sensor input = 41.5 litres
6.1 0652 Total tank level averaged = 65.2 litres
1_6.2 0667 Indicated value and tank phase.
1 = Both sensors OK. 2 = One sensor fault.3 = implausible input
Test 7: Temperature and speed 7.0 032 Coolant temperature input 32C (90F)
7.1 245 Outside temperature input 24.5C (76F)
7.2 5283 Engine speed 5,283 RPM
7.3 085 Vehicle speed 58 km/h (36 mph)
Test 8: Input values in HEX code 8.0-8.3 XXX Hex code, instrument cluster inputs
Test 9: battery voltage 9.0 125 12.5 Volts
Test 10: Country coding 10.0 02 US 02
Test 11: Cluster code 11.0 000003 Cluster code
Test 12: Not used
Test 13: Gong test 13.0 GONG Activate gong by pressing button (gong response is delayed)
Test 14: Fault memory (not used for diagnosis)
Test 15 - 18: Not used
Test 19: Lock/unlock 19.0 L-On L-Off Lock/unlock specific test functions
Test 20: Average fuel consumption correction factor 20.0 XXX9 Press button when correct 1s position is attained
20.1 XX5X Press button when correct 10s position is attained
20.2 12XX Press button when correct 100s position is attained
Test 21: Software reset 21.0 reset Reset software
Perform the following steps to access the instrument cluster self test functions:
1.Remove and insert ignition key (ignition OFF)
2.Press and hold RIGHT cluster button. gCHECK CONTROL OKh is displayed.
3.Without releasing button, turn ignition switch to first dent (RADIO position). gTEST-NR. 01 is displayed.
4.Press LEFT cluster button for the test sub-menus.
5.Press RIGHT cluster button to scroll to next test.
Note:
Test 1 and 2 are always unlocked
Test 3-21 are only accessible after unlocking using TEST-NR. 19 lock/unlock function. See Instrument cluster self test, unlocking.
Instrument cluster self test, unlocking
To unlock a specific test:
1.Remove and insert ignition key (ignition OFF)
2.Press and hold RIGHT cluster button. gCHECK CONTROL OKh is displayed.
3.Without releasing button, turn ignition switch to first dent (RADIO position). gTEST-NR. 01 is displayed.
4.Use RIGHT cluster button to scroll to TEST-NR. 19 (lock/unlock)
5.Press LEFT cluster button once to access TEST-NR. 19 submenu. gLOCK : ONh is displayed
6.Use LEFT cluster button to scroll to test you wish to unlock.
7.Press RIGHT cluster button once to unlock desired test. Display returns to TEST-NR. 01.
8.Scroll to unlocked test using RIGHT cluster button.
9.Press LEFT cluster button to perform desired test or access that tests submenu.
10.Repeat unlock sequence for each test required.
11.Switch ignition OFF to cancel self test mode.
Note: Display shows no visual confirmation of test unlock.
Instrument cluster, software reset
To reset instrument cluster software:
1.Remove and insert ignition key (ignition OFF)
2.Press and hold RIGHT cluster button. gCHECK CONTROL OKh is displayed.
3.Without releasing button, turn ignition switch to first dent (RADIO position). gTEST-NR. 01 is displayed.
4.Use RIGHT cluster button to scroll to TEST-NR. 19 (lock/unlock)
5.Press LEFT cluster button once to access TEST-NR. 19 submenu. gLOCK : ONh is displayed
6.Use LEFT cluster button to scroll to TEST-NR. 21. gLOCK : 21 is displayed
7.Press Right cluster button to unlock TEST-NR. 21. Display returns to TEST-NR. 01.
8.Use RIGHT cluster button to scroll to TEST-NR. 21.
9.Use LEFT cluster button to access TEST-NT. 21 sub-menu. gREST ?h is displayed.
10.Press LEFT cluster button again to perform reset.
11.Switch ignition OFF to cancel self test mode.
Note: Display shows no visual confirmation of test unloc
Menu Sub menu Sample Meaning
Test 1: Vehicle specific data 1.0 12345 VIN
1.1 4812 Body number
6_1.2 834762 Part number of cluster
1.3 010203 Coding/Diagnosis/Bus index
1.4 3495 Manufacturing data (calender week/year
1.5 04_600 Hardware/software number of cluster
3_1.6 415_06 Injection status, number of cylinders, engine factor
Test 2: Cluster system test Activates test for gauge drivers, indicators and LEDs
Test 3: SI data 3.0 1500 Litres
3.1 0 Periodic inspection days (not applicable for US)
Test 4: Fuel consumption data (current) 4.0 0267 26.7 litres/1000km
4.1 0073 7.3 litres/hour
Test 5: Fuel consumed/distance travelled 5.0 0195 19.5 litres/100km
5.1 226 Momentary distance to go (22km)
Test 6: Fuel level sensor input in litres 6.0 237415 Fuel level averaged.
LH sensor input = 23.7 litres - RH sensor input = 41.5 litres
6.1 0652 Total tank level averaged = 65.2 litres
1_6.2 0667 Indicated value and tank phase.
1 = Both sensors OK. 2 = One sensor fault.3 = implausible input
Test 7: Temperature and speed 7.0 032 Coolant temperature input 32C (90F)
7.1 245 Outside temperature input 24.5C (76F)
7.2 5283 Engine speed 5,283 RPM
7.3 085 Vehicle speed 58 km/h (36 mph)
Test 8: Input values in HEX code 8.0-8.3 XXX Hex code, instrument cluster inputs
Test 9: battery voltage 9.0 125 12.5 Volts
Test 10: Country coding 10.0 02 US 02
Test 11: Cluster code 11.0 000003 Cluster code
Test 12: Not used
Test 13: Gong test 13.0 GONG Activate gong by pressing button (gong response is delayed)
Test 14: Fault memory (not used for diagnosis)
Test 15 - 18: Not used
Test 19: Lock/unlock 19.0 L-On L-Off Lock/unlock specific test functions
Test 20: Average fuel consumption correction factor 20.0 XXX9 Press button when correct 1s position is attained
20.1 XX5X Press button when correct 10s position is attained
20.2 12XX Press button when correct 100s position is attained
Test 21: Software reset 21.0 reset Reset software
Perform the following steps to access the instrument cluster self test functions:
1.Remove and insert ignition key (ignition OFF)
2.Press and hold RIGHT cluster button. gCHECK CONTROL OKh is displayed.
3.Without releasing button, turn ignition switch to first dent (RADIO position). gTEST-NR. 01 is displayed.
4.Press LEFT cluster button for the test sub-menus.
5.Press RIGHT cluster button to scroll to next test.
Note:
Test 1 and 2 are always unlocked
Test 3-21 are only accessible after unlocking using TEST-NR. 19 lock/unlock function. See Instrument cluster self test, unlocking.
Instrument cluster self test, unlocking
To unlock a specific test:
1.Remove and insert ignition key (ignition OFF)
2.Press and hold RIGHT cluster button. gCHECK CONTROL OKh is displayed.
3.Without releasing button, turn ignition switch to first dent (RADIO position). gTEST-NR. 01 is displayed.
4.Use RIGHT cluster button to scroll to TEST-NR. 19 (lock/unlock)
5.Press LEFT cluster button once to access TEST-NR. 19 submenu. gLOCK : ONh is displayed
6.Use LEFT cluster button to scroll to test you wish to unlock.
7.Press RIGHT cluster button once to unlock desired test. Display returns to TEST-NR. 01.
8.Scroll to unlocked test using RIGHT cluster button.
9.Press LEFT cluster button to perform desired test or access that tests submenu.
10.Repeat unlock sequence for each test required.
11.Switch ignition OFF to cancel self test mode.
Note: Display shows no visual confirmation of test unlock.
Instrument cluster, software reset
To reset instrument cluster software:
1.Remove and insert ignition key (ignition OFF)
2.Press and hold RIGHT cluster button. gCHECK CONTROL OKh is displayed.
3.Without releasing button, turn ignition switch to first dent (RADIO position). gTEST-NR. 01 is displayed.
4.Use RIGHT cluster button to scroll to TEST-NR. 19 (lock/unlock)
5.Press LEFT cluster button once to access TEST-NR. 19 submenu. gLOCK : ONh is displayed
6.Use LEFT cluster button to scroll to TEST-NR. 21. gLOCK : 21 is displayed
7.Press Right cluster button to unlock TEST-NR. 21. Display returns to TEST-NR. 01.
8.Use RIGHT cluster button to scroll to TEST-NR. 21.
9.Use LEFT cluster button to access TEST-NT. 21 sub-menu. gREST ?h is displayed.
10.Press LEFT cluster button again to perform reset.
11.Switch ignition OFF to cancel self test mode.
Note: Display shows no visual confirmation of test unloc
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