VAG-COM logged - do these readings look like a dodgy MAF?

[ronaldmacdonald]

Following the very convincing pasting by the M3 the other day I decided to go and do some logging with the VAG-COM. Do these look reasonable readings? I think MAF looks very low to me.

Figures for 2nd gear:

TIME ENGINE ENGINE INJECTION MASS AIR
STAMP SPEED LOAD% TIME ms FLOW g/s

0.03 1480 47.4 6.12 21.31
0.61 1720 45.9 5.44 23.53
1.12 1920 40.6 5.1 22.5
1.82 2080 37.6 4.76 22.56
2.51 2280 40.6 5.44 31.61
3.06 2480 44.4 5.44 33
3.63 2760 51.1 6.46 42.36
4.23 3000 51.1 6.46 46
4.74 3240 50.4 6.46 47.47
5.26 3440 48.9 6.46 48.94
5.85 3680 47.4 6.12 50.08
6.45 3920 51.9 6.8 59.5
7.07 4160 49.6 6.12 59.25
7.69 4400 48.1 6.12 61.58
8.22 4560 47.4 6.12 63.22
8.89 4800 46.6 6.12 64.11
9.53 5000 48.9 6.46 71.08
10.1 5200 47.4 6.12 70.75
10.69 5360 45.9 5.78 71.28
11.26 5520 44.4 5.78 70.03
11.85 5680 46.6 6.12 77.75
12.47 5840 45.9 5.78 76.14
13.06 6000 44.4 5.78 75.75
13.68 6160 45.9 6.12 81.47
14.32 6320 45.9 6.12 83.89
14.94 6480 45.9 6.12 86.75
15.57 6640 45.9 5.78 87.86
16.2 6760 41.4 5.44 79.56


Figures for 3rd gear:

TIME ENGINE ENGINE INJECTION MASS AIR
STAMP SPEED LOAD% TIME ms FLOW g/s

16.8 5960 11.3 2.04 18.56
17.37 5240 11.3 1.7 15.58
17.91 4360 48.9 4.76 69.03
18.52 4440 70.7 9.18 109.22
19.06 4520 65.4 7.82 83.58
19.59 4640 63.2 8.16 85.89
20.14 4760 64.7 8.5 91.28
20.69 4880 69.9 9.18 100.81
21.25 5000 69.2 8.84 101.83
21.8 5120 69.2 8.84 105.47
22.37 5280 74.4 9.52 114.5
22.95 5400 76.7 10.2 120.5
23.55 5560 77.4 10.2 126
24.12 5680 76.7 9.86 128.75
24.73 5840 75.2 9.86 128.75
25.36 6000 72.9 9.52 126.61
25.95 6120 73.7 9.52 131.31
26.57 6240 73.7 9.52 134.5
27.2 6360 73.7 9.86 136.94
27.83 6480 73.7 9.86 139.47
28.46 6640 72.9 9.86 141.58
29.1 6720 72.9 9.86 143.28
29.71 6520 12 1.7 1.06

[saf]

Hello mate, you need to log third gear from a low rev such as 3000 all the way up to red line (roughly 100mph)
Do this on motorway (up to 70mph or so, he he ) or private road.

That will give an indication of your peak MAF reading.

Let us know if your car is stock , or if you have an exhaust or remap or both?

You should be peaking between 215 and 220 at highest RPM in third gear as far as i know. Someone will be along to correct me if I am wrong.

Just had second look at your results:

Does look like a doggy MAF though with those results you got. You really need to put your foot down all the way from 3000k rpm to 6800 without letting go of throttle. once thats logged shoudl get a propper reading. I think your MAF is doggy though.

[ronaldmacdonald]

lol, i was papping it a bit on the "private road", daredn't give it another go just yet - iv'e never seen the oil temp bend round to the 120 mark, not sure it was doing the mota any good. its just a standard avant but its either maf or boost leak. going to try unplugging the maf as well to see what happens

[saf]

Also how did you log this? Im curious to know whcih measuring block you logged?

plz explain.

[ronaldmacdonald]

Ive only got the freeware v409.1 VAG-COM, anyway just went into the Engine Module -> Measuring Blocks -> Group 002. Because its freeware I think a lot of the features are blanked out so it only gives you the basic stuff - still the useful part of the basic stuff lol

[saf]

log on measuring block 3. you can select it on freeware. Thats what i was told to do and it does work on freeware.

Your oil temp is very very worrying.

It should no way be at the 120 mark.

At the most, kicking your car about the street with a heavy foot, should see a standard S4's oil temp not going much more over 100 degrees and thats with constant boost supplied by your right foot.

My friends S4 hits 120 degrees when doing this and hes is a stage 2 SKN.

Mines never seen 120 degrees, Not even when on motorway. 110 ish, but not 120, and thats driving it hard.

Keep an eye on your oil temp mate and get car seen to as quick as posible., Change MAF tomorrow just to be on safe side. Best to spend 90 quid rather than buy new turbos and fit them for about 2.5K

[maxxximus]

Doesnt look right for stock- you should be seeing a peak at around 215 WOT. Best log 003 then you can tell when your booting it - throttle angle 100%.

Oil temps sound high as well - mine rarely goes above 100 even after spirited driving

You need to get it looked at.

Edit : Safs beaten me to it

[ronaldmacdonald]

Doesnt look right for stock- you should be seeing a peak at around 215 WOT. Best log 003 then you can tell when your booting it - throttle angle 100%.

Oil temps sound high as well - mine rarely goes above 100 even after spirited driving

You need to get it looked at.

Edit : Safs beaten me to it

ill have a look for block 003, it only seemed to have the option of 001 and 002 although I guess I could have typed in 003?

[maxxximus]

Log 003 for future reference but i wouldnt bother with it now - youve got enough info there.

First thing - get it looked at.

[Dippy]

If you still have the DTCs (other post) then you have the info you need, these logs just prove the MAF is dead.

[JonnyX]

Low MAF = running lean = HOT = high oil temps and high EGT's.

[ronaldmacdonald]

Low MAF = running lean = HOT = high oil temps and high EGT's.

I'm waiting on a new MAF right now, when I get under there hopefully next week Im going to check all the hoses over. I am seriously considering putting a new N75 in as well as a couple of new 710N's whilst I'm at it

Thanks for the replies guys, ill post the results of the VAG-COM measuring blocks once Ive swapped the MAF over and also remember to floor it pedal to the metal whilst doing the test lol

[DavidT]

I could be wrong (it happens often) but your logs look OK to me, based on not being at full throttle. Try again using full throttle in 3rd gear, 4k - rev limiter.