Is a or both turbos go bad will it throw a code??

[makaveli42]

So haven't drove the beast in a while...clean it up and drive it around and I notice it's extreme slow compared to usual. Also I can't hear the turbos spool anymore?!? I have a straight piped exhaust and usually can hear them spool they the entire RPMs! I ran codes and only thing to come up was the damn radio code where it doesn't get an ignition feed or whatever. Pretty much the radio won't shut off when the car is off and key is out. I cleared the codes and went out for a drive...same thing. When I floor it now the exhaust sounds like an old straight piped farm truck instead of an Audi TT V8. Like it had that old crappy raspy sound. It's not 4 cylinder slow by anymeans...just no where near where it was? I don't think I'm in limp mode because that would have thrown a code right? I drove her up on ramps and checked all the hoses and they are on there nice and tight! Even had the wife rev it while I was under it to see if I had an exhaust leak that was making it sound different....nope, no leak!

only think I can think of is one of the turbos isn't spooling?? But the car doesn't smoke or smell funny...

just had a baby last week so it's been crazy at home, trying to find time to drop it off at the shop. Just hoping for some RS6.com knowledge before hand!

Thanks!

[DHall1]

Log

3,31,115

reset

log it again

[makaveli42]

Log

3,31,115

reset

log it again

Was gonna log but but didn't wanna push the car too hard if it's hurt....I guess if that's the only way I'll do it tomorrow after work.

[DHall1]

You don't have to go far

second gear pull is fine

dont need it to redline either

4500-5000 is fine

[makaveli42]

okay ran some logs.. ran and cleared codes...ran more logs. all the same definitely running LOW boost for some reason????

ANY IDEAS???

Group A: '003 Group B: '031 Group C: '115
Engine Speed Mass Air Flow Throttle Valve Angle IgnitionLambda Lambda Lambda Speed Load Boost Boost
TIME (G28) (G70 + G246) Timing Angle TIME Bank 1 Bank 1 Bank 2 Bank (G28) specified) (actual)
STAMP /min g/s % °BTDC STAMP V V V V STAMP /min % mbar mbar
0.08 1720 37.67 13.3 27 0.01 0.535 0 0.1 0 0.04 1720 50.4 980 990
0.18 1720 37.67 13.3 27.8 0.11 0.57 0 0.305 0 0.14 1720 49.6 980 990
0.29 1760 46.22 15.7 27 0.23 0.63 0 0.07 0 0.26 1760 50.4 980 990
0.39 1840 51.53 17.3 27 0.33 0.66 0 0.065 0 0.36 1800 55.6 1020 990
0.49 1920 54.14 18 28.5 0.42 0.71 0 0.13 0 0.45 1880 58.6 1030 990
0.61 2000 58.03 20.4 27 0.54 0.74 0 0.79 0 0.58 1960 61.7 1110 1000
0.74 2040 62.58 23.1 27.8 0.65 0.25 0 0.775 0 0.7 2040 62.4 1180 1000
0.83 2120 62.5 24.3 27.8 0.77 0.07 0 0.74 0 0.8 2080 64.7 1210 1000
0.93 2160 65.31 26.3 28.5 0.86 0.07 0 0.665 0 0.89 2120 65.4 1210 1000
1.04 2200 70.44 29.4 28.5 0.98 0.075 0 0.09 0 1.01 2160 66.9 1240 1000
1.15 2240 72.72 32.5 25.5 1.07 0.135 0 0.145 0 1.11 2240 68.4 1290 1000
1.27 2320 74.11 32.2 26.3 1.2 0.665 0 0.7 0 1.24 2280 69.2 1310 1010
1.36 2320 75.25 32.5 27 1.3 0.68 0 0.685 0 1.33 2320 69.9 1300 1010
1.49 2360 76.53 32.9 27.8 1.4 0.655 0 0.69 0 1.45 2360 70.7 1320 1020
1.61 2440 81.11 34.5 26.3 1.54 0.565 0 0.7 0 1.58 2400 71.4 1320 1020
1.74 2520 87.89 71.4 27.8 1.65 0.63 0 0.705 0 1.7 2480 74.4 1420 1020
1.83 2560 90.67 87.5 28.5 1.77 0.595 0 0.6 0 1.8 2520 75.9 1690 1020
1.93 2560 93.39 96.1 27.8 1.86 0.59 0 0.695 0 1.89 2560 76.7 1710 1030
2.05 2560 91.06 98.4 27.8 1.98 0.075 0 0.335 0 2.01 2520 78.2 1810 1040
2.15 2600 93 99.2 27 2.08 0.66 0 0.71 0 2.11 2560 78.9 2130 1040
2.27 2600 94.47 100 28.5 2.2 0.71 0 0.76 0 2.24 2600 80.5 2230 1040
2.37 2640 98 100 25.5 2.3 0.67 0 0.785 0 2.33 2640 79.7 2220 1060
2.49 2680 99.75 100 27 2.42 0.775 0 0.825 0 2.45 2680 81.2 2220 1060
2.58 2760 104.25 100 27 2.52 0.805 0 0.835 0 2.55 2720 82 2220 1060
2.7 2800 104.94 100 27 2.61 0.815 0 0.835 0 2.65 2800 82 2220 1070
2.83 2880 111.42 100 27 2.74 0.81 0 0.825 0 2.79 2840 82.7 2210 1070
2.95 2960 107.89 100 27 2.86 0.8 0 0.83 0 2.9 2920 83.5 2210 1080
3.05 3000 116.97 100 27.8 2.99 0.815 0 0.835 0 3.02 3000 83.5 2210 1080
3.14 3080 118.06 100 27 3.08 0.805 0 0.82 0 3.11 3040 83.5 2200 1090
3.26 3120 121.36 100 27 3.17 0.805 0 0.825 0 3.21 3120 84.2 2200 1090
3.37 3200 123.5 100 27 3.29 0.805 0 0.825 0 3.33 3200 85 2190 1100
3.49 3240 125.53 100 27 3.42 0.81 0 0.82 0 3.45 3240 85.7 2190 1100
3.58 3320 132.28 100 27 3.52 0.815 0 0.825 0 3.55 3320 86.5 2180 1100
3.68 3400 131.97 100 27 3.61 0.81 0 0.83 0 3.64 3360 85.7 2170 1120
3.79 3440 141.53 100 24.8 3.73 0.805 0 0.825 0 3.76 3440 87.2 2170 1110
3.89 3480 140.69 100 24 3.83 0.815 0 0.825 0 3.86 3480 87.2 2170 1130
4.01 3560 140.81 100 24.8 3.93 0.815 0 0.825 0 3.98 3520 88.7 2160 1130
4.11 3640 146.5 100 25.5 4.05 0.815 0 0.82 0 4.08 3600 89.5 2160 1140
4.23 3680 151.25 100 23.3 4.14 0.815 0 0.83 0 4.18 3680 89.5 2150 1150
4.32 3760 155.94 100 24.8 4.26 0.815 0 0.82 0 4.29 3720 90.2 2140 1150
4.45 3840 162.22 100 24 4.36 0.815 0 0.82 0 4.4 3800 91.7 2150 1160
4.57 3920 167.47 100 23.3 4.5 0.81 0 0.82 0 4.54 3880 92.5 2140 1170
4.68 4000 169.97 100 23.3 4.61 0.81 0 0.82 0 4.64 3960 92.5 2130 1190
4.79 4080 173.42 100 22.5 4.73 0.805 0 0.815 0 4.76 4040 94 2130 1190
4.89 4120 184.47 100 20.3 4.83 0.8 0 0.81 0 4.86 4120 95.5 2120 1200
5.01 4200 189.5 100 20.3 4.93 0.81 0 0.82 0 4.98 4200 96.2 2110 1220
5.1 4280 187.47 100 21.8 5.04 0.795 0 0.815 0 5.07 4240 97 2100 1220
5.21 4360 196.58 100 21.8 5.14 0.8 0 0.815 0 5.18 4320 98.5 2100 1240
5.3 4400 198.53 100 21.8 5.24 0.81 0 0.81 0 5.27 4400 99.2 2090 1250
5.41 4480 207.72 100 21 5.33 0.805 0 0.8 0 5.38 4440 101.5 2090 1260
5.52 4560 216.28 100 17.3 5.45 0.8 0 0.81 0 5.48 4520 100.8 2080 1280
5.63 4640 220.81 100 16.5 5.57 0.8 0 0.805 0 5.6 4600 102.3 2070 1290
5.74 4720 224.75 100 18.8 5.66 0.79 0 0.81 0 5.71 4680 105.3 2060 1290
5.85 4800 230.42 100 19.5 5.78 0.795 0 0.805 0 5.82 4760 105.3 2050 1320
5.96 4880 246.22 100 14.3 5.88 0.745 0 0.79 0 5.91 4840 108.3 2030 1320
6.07 4960 255.47 100 15 5.99 0.77 0 0.805 0 6.02 4920 110.5 2010 1330
6.18 5040 265.19 99.6 17.3 6.1 0.78 0 0.805 0 6.14 5000 112 2000 1350
6.3 5120 266.47 100 17.3 6.23 0.76 0 0.8 0 6.26 5080 112.8 1990 1380
6.43 5200 276.97 100 13.5 6.34 0.77 0 0.795 0 6.38 5160 115 1980 1400
6.55 5320 283.31 100 16.5 6.48 0.79 0 0.815 0 6.51 5280 118 1960 1400
6.7 5400 297.5 100 15.8 6.6 0.785 0 0.81 0 6.65 5400 115.8 1950 1450
6.82 5520 303.28 100 12.8 6.73 0.775 0 0.8 0 6.78 5480 120.3 1940 1450
6.95 5600 308.64 100 12.8 6.87 0.785 0 0.8 0 6.92 5560 121.8 1930 1470
7.07 5680 320.39 100 12.8 6.99 0.8 0 0.8 0 7.02 5680 121.1 1920 1490
7.22 5800 322.97 99.6 14.3 7.12 0.755 0 0.8 0 7.17 5760 122.6 1900 1510
7.34 5880 325.97 100 14.3 7.26 0.74 0 0.8 0 7.29 5840 123.3 1900 1520
7.46 5960 326.92 100 17.3 7.39 0.785 0 0.82 0 7.42 5960 121.8 1890 1520
7.59 6080 332.53 100 13.5 7.51 0.77 0 0.79 0 7.55 6040 123.3 1880 1550
7.73 6160 338.08 100 13.5 7.64 0.785 0 0.795 0 7.69 6120 121.8 1870 1550
7.86 6240 342.53 99.6 13.5 7.76 0.77 0 0.805 0 7.81 6200 121.1 1860 1570

[makaveli42]

holy crap.....dont have excel on the laptop anymore...sorry it looks so whack. lol

[DHall1]

My brain hurts looking at those numbers

[makaveli42]

My brain hurts looking at those numbers

Ha. Yeah. My bad. I'll try and use pics? If not I'll have to email it to a friend with excel and cut it down.



pretty much my specified boost is 2010 and the actual is 1100. Which is jacked up. Just dunno how or why?

[DHall1]

You are making some boost

start looking for leaks

diverter valves

n75

n249

higher rpm I'm seeing .5bar boost

[makaveli42]

My DVs are original...if one of them is stuck shut, would that cause the boost issue? Just wondering why the exhaust note changed.

as long as my turbos are okay I won't be as freaked out lol

[Bigglezworth]

Blowing off pressure somewhere. Like Dave said. N75 or DV would be my first place I would look. I always have spares of these, so I do the non-tech way of just swapping out one at a time until the fault is located. I'm sure the manual provides a more technical manner in which to diagnose a fault.

[mbagge01]

I am actually curious that in a biturbo system, what is the typical symptom if one turbo fails. Is it just lower max boost or do you get fuel trim issues or other problems on one bank?

[DHall1]

You hear it

then it goes boom

[Bigglezworth]

Your EGT sensor will spike signifying an impending failure, and then you will have a ride that performs more like an S6... The single compressor can't feed the same amount of boost to 8 cylinders and you have a reduction in total power output as a result. Turbo failures aren't as common as one would think. I'd put my money on the other items before getting yourself worried about a turbo.