lack of whistle from turbo

I recently posted:
"Also, another question on a different matter - When i first bought the car i had to replace the MAF (surprise, surprise) afterwhich the power seemed fine. The only concern is that i don't hear a whine coming from the turbo when i accelerate. Is this something to worry about, only i used to own a '00 golf tdi and the sound of the turbo was loud and lovely.
Again, any thoughts or things that i can try??? "

I have just had her out for a spin and the power is definately there, and the acceleration seems okay, but there is no obvious whistle coming from the turbo. I don't know if it means anything relative, but i notice that when i turn the car off i get the noise of air releasing for approx 30-60 seconds - someone told me that it is the heating matrix, but the climatronic is working fine.
I hope that everything is alright, as the car feel good to drive, but i do like the sound of a whistling turbo.
By the way, i drive a '99 Passat B5 TDI 90BHP - I live in ireland.

I appreciate all your views as I am only learning about my car.

I'd chalk it up to the B5 having a North-South engine arrangement while your Golf had a West-East engine arrangement. The Golf had its turbo sandwiched between the engine block and the firewall while the B5 has the turbo sandwiched between the engine block and the wheelwell, some 15-24 inches away from the firewall.

If you want to hear the turbo then change your airbox for an aftermarket cone filter. When I ran a PiperX filter on my car it was noticeably louder. I changed it back to the stock airbox because I was tired of kids wanting to race me at every light because they heard my turbo.

/images/graemlins/wink.gif No turbo whistle? Quit feeding it dry crackers!! [end joke mode].

OK, it could be this: the turbocharger is quite small and can spin up very quickly. Can you hear the whine from behind the car at idle?

If you are getting better power, it very well could be that the turbine is now spinning faster and being accelerated very quickly to the rpms that produce ultrasonic frequencies that your ears can't hear.

Also, your engine may be making a little more noise that drowns out the turbine sound.

Check with the window down at low speed by a wall or something that will reflect the sound back so you can hear it. Maybe that isn't much fun this time of year, but once or twice might tell you something.

I can only hear my 02 Golf whine in an enclosed space or near a retaining wall etc.

i can always hear my turbo whistle ... it's more prominent in an enclosed area, but if you listen close you can always hear it...

as for why the passat's doesn't whistle, well that i have no idea /images/graemlins/tongue.gif

Passats have a double fire wall and a lot more sound insulation as well.

I hate to churn this up again but I'm having the same situation. Turbo used to whine and I did the clutch and put all back together. No whine. Replaced all vacuum hoses and everything and turbo WORKS. I know this because at high speeds I'll get overboost condition and power will vanish lol. Something happened when had engine unbolted and jack fell down, lol. Nonetheless the turbo works but does not whistle?!

jagster936 said:

I hate to churn this up again but I'm having the same situation. Turbo used to whine and I did the clutch and put all back together. No whine. Replaced all vacuum hoses and everything and turbo WORKS. I know this because at high speeds I'll get overboost condition and power will vanish lol. Something happened when had engine unbolted and jack fell down, lol. Nonetheless the turbo works but does not whistle?!

Click to expand...

The vanes are clogged and not properly working if the n75 is sending proper vacuum. If you put a mightyvac on the line to the actuator with the car off and actuate it you will hear squeaking or a small whistle when it pops free.

You can also loosen the 2 nuts on the actuator and move it back and forth by hand. If it feels crunchy than its dirty and a cleaning will help.


Sent from my iPhone using Tapatalk

Yea I need to double check getting full vacuum amount and the valve. Car was fine before all this. Almost seems like actuator was somehow distorted in the clutch process

I'll put a mighty vac on it too.

Any ideas full vacuum values? Near full?

I have some good vag com data:

29.06 924 999.6 1009.8 24.7
29.37 945 999.6 1009.8 24.7
29.68 903 999.6 1009.8 24.7
29.99 903 999.6 1009.8 24.7
30.31 903 999.6 1009.8 24.7
30.62 903 999.6 1009.8 24.7
30.93 903 999.6 1009.8 24.7
31.24 903 999.6 1009.8 24.7
31.56 903 999.6 1009.8 24.7
31.87 903 999.6 1009.8 24.7
32.19 903 999.6 1009.8 24.7
32.5 903 999.6 1009.8 24.7
32.81 903 999.6 1009.8 24.7
33.12 903 999.6 1009.8 24.7
33.43 903 999.6 1009.8 24.7
33.74 903 999.6 1009.8 24.7
34.06 903 999.6 1009.8 24.7
34.37 903 999.6 1009.8 24.7
34.68 903 999.6 1009.8 24.7
34.99 903 999.6 1009.8 24.7
35.31 903 999.6 1009.8 24.7
35.62 903 999.6 1009.8 24.7
35.93 903 999.6 1009.8 24.7
36.25 903 999.6 1009.8 24.7
36.56 903 999.6 1009.8 24.7
36.87 903 999.6 1009.8 24.7
37.18 903 999.6 1009.8 24.7
37.49 903 999.6 1009.8 24.7
37.81 903 999.6 1009.8 24.7
38.12 903 999.6 1009.8 24.7
38.43 903 999.6 1009.8 24.7
38.75 903 999.6 1009.8 24.7
39.06 903 999.6 1009.8 24.7
39.37 903 999.6 1009.8 24.7
39.68 903 999.6 1009.8 24.7
40 903 999.6 1009.8 24.7
40.31 903 999.6 1009.8 24.7
40.62 903 999.6 1009.8 24.7
40.93 903 999.6 1009.8 24.7
41.24 903 999.6 1009.8 24.7
41.56 903 999.6 1009.8 24.7
41.87 903 999.6 1009.8 24.7
42.18 903 999.6 1009.8 24.7
42.5 903 999.6 1009.8 24.7
42.81 903 999.6 1009.8 24.7
43.12 903 999.6 1009.8 24.7
43.43 903 999.6 1009.8 24.7
43.74 903 999.6 1009.8 24.7
44.06 903 999.6 999.6 24.7
44.37 903 999.6 1009.8 24.7
44.68 903 999.6 1009.8 24.7
44.99 903 999.6 1009.8 24.7
45.31 903 999.6 1009.8 24.7
45.62 903 999.6 1009.8 24.7
45.93 903 999.6 1009.8 24.7
46.25 903 999.6 1009.8 24.7
46.56 903 999.6 1009.8 24.7
46.87 882 999.6 1009.8 24.7
47.18 882 999.6 1009.8 24.7
47.49 882 999.6 999.6 24.7
47.81 966 999.6 1009.8 24.7
48.12 924 999.6 1009.8 24.7
48.43 882 999.6 1009.8 24.7
48.74 882 999.6 1020 24.7
49.06 882 1009.8 1020 24.7
49.37 819 1111.8 1020 24.7
49.68 1155 1060.8 1020 24.7
50 1239 1060.8 1030.2 24.7
50.31 1386 1071 1040.4 37.5
50.62 1554 1111.8 1050.6 33.9
50.93 1680 1122 1071 35.9
51.24 1827 1132.2 1091.4 39.4
51.56 1638 999.6 1122 45.8
51.87 1260 999.6 1101.6 45
52.18 1113 1030.2 1081.2 28.3
52.5 1134 1111.8 1071 25.1
52.81 1218 1448.4 1071 27.9
53.12 1344 1479 1091.4 25.9
53.43 1449 1499.4 1111.8 24.7
53.74 1575 1499.4 1142.4 25.1
54.06 1701 1479 1173 24.7
54.37 1806 1489.2 1203.6 27.5
54.68 1911 1122 1244.4 26.3
54.99 1575 999.6 1224 53.4
55.31 1176 999.6 1152.6 42.6
55.62 1323 1050.6 1091.4 41.8
55.93 1260 1193.4 1091.4 33.5
56.24 1323 1642.2 1101.6 33.9
56.56 1365 1703.4 1122 24.7
56.87 1428 1754.4 1142.4 27.9
57.18 1470 1805.4 1162.8 25.9
57.49 1533 1846.2 1193.4 24.7
57.81 1596 1897.2 1224 24.7
58.12 1638 1938 1254.6 24.7
58.43 1701 1968.6 1285.2 24.7
58.74 1764 2019.6 1326 25.1
59.06 1806 2070.6 1377 24.7
59.37 1869 2111.4 1438.2 24.7
59.68 1953 2162.4 1581 38.6
60 2058 2193 1764.6 47.4
60.31 2163 2193 1958.4 57
60.62 2289 2193 2152.2 63.4
60.93 2373 2193 2315.4 68.5
61.24 2478 2193 2448 74.5
61.56 2583 2193 2550 79.3
61.87 2667 2193 2570.4 81.7
62.18 2772 2193 2570.4 85.7
62.49 2877 2193 2570.4 88.9
62.81 2961 2193 2570.4 91.6
63.12 3066 2193 2570.4 94.4
63.43 3150 2193 2570.4 94.4
63.74 3234 2193 2570.4 94.4
64.06 3318 2193 2570.4 94.4
64.37 3381 2193 2570.4 94.4
64.68 3465 2193 2570.4 94.4
64.99 3528 2193 2570.4 94
65.31 3591 2193 2570.4 94
65.62 3675 2193 2570.4 94.4
65.93 3717 2193 2560.2 94.4
66.25 3780 2193 2550 94.4
66.56 3843 2193 2550 94.4
66.87 3885 2193 2539.8 93.6
67.18 3948 2193 2529.6 94.4
67.49 3990 2193 2509.2 92.4
67.81 3990 2193 2499 92.4
68.12 4032 2193 2295 92.4
68.43 4011 2193 2060.4 92.4
68.74 3990 2193 1968.6 92.4
69.06 3990 2193 1927.8 92.4
69.37 3969 2193 1907.4 92.4
69.68 3948 2193 1897.2 92.4
69.99 3927 1152.6 1887 92.4
70.31 3507 1060.8 1754.4 92.4
70.62 2898 1040.4 1499.4 92.4
70.93 2352 1009.8 1346.4 92.4
71.25 1932 999.6 1244.4 92.4
71.56 1533 999.6 1162.8 92.4
71.87 1155 999.6 1111.8 92.4
72.18 777 999.6 1081.2 92.4
72.49 924 999.6 1060.8 92.4
72.81 903 999.6 1040.4 92.4
73.12 903 999.6 1030.2 92.4

You can see as the turbo spins up it overboosts and valve is open but veins arent closing enough. Weird stuff. Happens around 4K rpm or at highway speeds.

Not sure how this effects whistle unless somehow it spins so fast you can't hear it all the time?!

Gazoo said:

I can only hear my 02 Golf whine in an enclosed space or near a retaining wall etc.

Click to expand...

me too