Boost Leak/N75 Duty Cycle

[MrBean31]

Hi all,

I have been doing some logs and feel like i might have a boost leak or my N75 is playing up, i have copied in the log below it was thrid gear to redline (The 2nd pull looks a tad worse) it shows the N75 duty cycle being only 95% till 2450rpm then it all over the place a when i thought it was supposed to be 95% thoughout the rev range? The boost figures look a little suspect aswell, i have done a few smoke tests but can never seem to find any leaks!

I also have a random 'honking'/'duck quack' sound coming from my engine which normally appears to be the DV so i have replaced it but no anvil, i'm guessing this could be the issue but can't find the source (Only happens when driving)

Any advice please? I had a quick Google by no defiant answers on N75, as far as i know the car is stock.

(MAF in Green, N75 figures in red)
Group A: '003
Engine Speed Mass Air Flow Ignition Boost Pressure Boost Pressure Boost Pressure
TIME (G28) Sensor (G70) Timing Angle Control (N75) (specified) (actual)
Marker STAMP /min g/s °BTDC % mbar mbar
0.25 2080 35.39 20.3 0 1070 1100
0.62 2200 43.83 18 95.3 1770 1200
1 2320 48.31 18.8 95.3 1750 1360
1.37 2440 59.22 12.8 95.3 1680 1510
1.75 2560 68.94 10.5 58.8 1630 1690
2.12 2720 72.78 10.5 49 1630 1780
2.5 2880 69.94 12 40.8 1600 1700
2.87 3040 72.83 12 38.8 1560 1610
3.25 3200 73.75 15 36.1 1550 1550
3.62 3360 81.72 15 36.9 1570 1550
4 3520 84.14 16.5 38 1600 1580
4.37 3640 86.58 16.5 38.4 1610 1590
4.75 3800 87.75 16.5 38.4 1600 1600
5.12 3920 95.56 16.5 38.4 1590 1580
5.5 4080 99.31 18.8 37.6 1590 1590
5.87 4240 101.47 15 38 1580 1580
6.25 4360 104.53 15 37.3 1570 1580
6.62 4520 109.31 17.3 37.3 1560 1570
7 4640 113.83 21 36.9 1560 1540
7.37 4800 117.61 16.5 37.6 1570 1540
7.75 4920 121.58 13.5 37.6 1570 1580
8.12 5080 126.69 15 37.3 1580 1560
8.5 5200 133.44 19.5 40.4 1590 1550
8.87 5360 134.56 12 40.8 1610 1610
9.25 5480 1 39.31 16.5 40.8 1620 1610
9.62 5600 143.75 15 42.4 1620 1620
10 5760 148.56 12.8 44.7 1630 1620
10.37 5880 147.56 21 45.5 1600 1620
10.75 5960 148.53 18 45.1 1600 1610
11.12 6120 148.25 16.5 45.1 1590 1620
11.5 6200 151.72 15 44.7 1590 1610
11.88 6320 148.31 15 43.1 1590 1550
12.25 6440 149.75 15 44.7 1590 1600

 

[jake davis]

afternoon mr bean,
just wondered if you ever figured out that annoying duck quack sound? mine does it aswell and its driving me crazy. ive posted a video on here but noone seems to know?

 

[Pie-eyedpiper]

I used to have a 1.9tdi SEAT Leon, it used to honk/quack on shutdown.
I figured it was the turbo actuator shaft moving to closure. Could have been wrong though.