jcman

Bruce it's got to be a bad connection or chaffed wire

AudiBruceH

I was hoping for something more simple! Hopefully I'll see something that looks suspicious in the wiring... Such a weird issue.

Thanks for the help-

AudiBruceH

Spent the afternoon trying to fine a connector or harness that would make the temp fluctuate when I move/adjust it. Took off and cleaned all the connectors/grounds I could find. After playing around watching rpm vs temp it's actually seeming more consistant than I originally thought. Here is a scenario I can reproduce pretty easy. At idle it holds pretty steady (not all the time, but usually) if I rev it up it the temp will rise and then drop fast when I go back to idle. Sorry for the long winded posts... and thanks to anyone bored enough to read this! Here is the output of rpm/temp. Note that the gauge temp is unmoving at normal temp. Not sure what to make of it.

Sunday 10 February 2013 17:11:14:08940 VCDS Version: Release 11.11.5
4D0 907 551 AH ADVMB 2.8L V6/5V MOTR AT D04
G001 F1 G002 F0

Marker TIME Group 1 - Field 1 TIME Group 2 - Field 0
STAMP Coolant Temp - 80-105C STAMP Engine speed - RPM
°C /min
0 94.5 0.27 680
0.52 94.5 0.78 640
1.04 94.5 1.3 680
1.57 94.5 1.83 680
2.09 94.5 2.35 640
2.6 94.5 2.86 680
3.13 94.5 3.38 640
3.65 94.5 3.91 680
4.18 94.5 4.43 680
4.69 94.5 4.95 640
5.21 94.5 5.47 680
5.73 94.5 5.98 680
6.23 94.5 6.5 680
6.78 94.5 7.03 680
7.29 94.5 7.55 680
7.81 94.5 8.07 680
8.34 94.5 8.6 680
8.88 94.5 9.13 640
9.4 94.5 9.66 680
9.91 94.5 10.17 680
10.43 94.5 10.68 680
10.92 94.5 11.17 680
11.43 94.5 11.7 720
11.96 94.5 12.23 960
12.49 94.5 12.74 1400
13 94.5 13.28 1600
13.54 94.5 13.8 1600
14.07 94.5 14.33 1640
14.61 94.5 14.86 1720
15.11 94.5 15.36 1880
15.61 94.5 15.86 1960
16.11 94.5 16.37 2040
16.64 94.5 16.9 2120
17.15 94.5 17.42 2160
17.68 94.5 17.93 2200
18.2 94.5 18.47 2240
18.73 94.5 18.98 2280
19.25 94.5 19.51 2320
19.76 94.5 20.03 2320
20.3 94.5 20.55 2320
20.81 94.5 21.08 2320
21.33 94.5 21.59 2360
21.85 94.5 22.1 2360
22.36 94.5 22.62 2360
22.88 94.5 23.14 2400
23.4 94.5 23.66 2400
23.92 94.5 24.17 2440
24.44 93 24.71 2480
24.97 93 25.22 2520
25.49 93 25.75 2560
26 93 26.25 2560
26.52 93 26.78 2600
27.03 93 27.3 2600
27.56 93 27.81 2640
28.07 93 28.34 2640
28.61 93 28.86 2640
29.11 93 29.37 2640
29.64 93 29.9 2640
30.16 93 30.42 2640
30.68 93 30.94 2680
31.2 93 31.46 2720
31.72 93 31.98 2760
32.24 93 32.5 2800
32.75 93 33.01 2840
33.27 93 33.52 2880
33.79 93 34.06 2880
34.32 93 34.57 2880
34.83 93 35.1 2880
35.35 93 35.61 2880
35.88 93 36.13 2880
36.39 93 36.66 2920
36.91 93 37.18 2920
37.44 93 37.69 2920
37.95 93 38.22 2920
38.48 93 38.74 2920
39 93 39.25 2960
39.52 93 39.77 2960
40.04 93 40.29 3000
40.54 93 40.81 3000
41.08 93 41.34 3040
41.59 93 41.86 3040
42.12 93 42.37 3080
42.64 93 42.9 3080
43.15 93 43.41 3080
43.67 93 43.94 3120
44.2 93 44.46 3120
44.72 93 44.98 3120
45.24 93 45.49 3120
45.75 93 46 3120
46.27 93 46.54 3120
46.79 93 47.05 3120
47.31 93 47.58 3120
47.83 93 48.1 3120
48.35 96 48.61 3120
48.88 96 49.13 3120
49.39 97.5 49.65 3120
49.9 99 50.16 3120
50.43 100.5 50.69 3080
50.96 102 51.22 3080
51.47 102 51.73 3120
52 102 52.24 3120
52.52 105 52.78 3160
53.04 108 53.3 3200
53.56 109.5 53.82 3200
54.07 111 54.33 3200
54.59 115.5 54.85 3200
55.12 117 55.38 3200
55.64 118.5 55.91 3240
56.16 120 56.42 3240
56.68 109.5 56.94 3240
57.2 111 57.45 3240
57.71 111 57.98 3240
58.24 109.5 58.49 3240
58.75 108 59 3240
59.26 106.5 59.52 3240
59.79 106.5 60.06 3240
60.31 111 60.57 3200
60.83 111 61.09 2800
61.35 111 61.61 2200
61.87 108 62.13 1480
62.39 106.5 62.66 1000
62.92 103.5 63.17 720
63.44 102 63.7 640
63.95 100.5 64.21 680
64.47 99 64.74 680
65 97.5 65.27 640
65.52 97.5 65.78 680
66.04 96 66.31 640
66.57 96 66.83 680
67.11 94.5 67.37 640
67.63 91.5 67.88 680
68.13 85.5 68.38 720
68.63 81 68.89 680
69.16 76.5 69.41 680
69.67 73.5 69.94 720
70.19 72 70.45 720
70.71 69 70.97 720
71.23 67.5 71.49 720
71.76 66 72.02 760
72.28 66 72.53 760
72.79 64.5 73.05 760
73.31 64.5 73.57 760
73.83 63 74.09 720
74.35 63 74.61 720
74.88 63 75.14 720
75.4 61.5 75.65 760
75.91 61.5 76.17 760
76.43 61.5 76.69 720
76.95 61.5 77.21 720
77.47 61.5 77.72 760
77.99 64.5 78.25 720
78.51 67.5 78.77 720
79.05 67.5 79.3 680
79.55 73.5 79.81 640
80.07 72 80.33 680
80.59 69 80.85 680
81.11 82.5 81.37 680
81.63 90 81.89 600
82.16 96 82.42 600
82.67 102 82.93 640
83.19 106.5 83.46 640
83.74 111 84 640
84.26 112.5 84.51 640
84.76 112.5 85.02 640
85.28 111 85.55 640
85.82 111 86.08 640
86.34 109.5 86.6 640
86.85 109.5 87.12 640
87.38 108 87.63 680
87.89 108 88.16 640
88.41 108 88.67 640
88.93 111 89.2 680
89.46 112.5 89.72 680
89.97 112.5 90.22 640
90.47 112.5 90.74 680
91 111 91.25 680
91.51 109.5 91.77 680
92.03 108 92.3 680
92.56 108 92.83 640
93.1 106.5 93.36 640
93.62 106.5 93.87 680
94.13 105 94.4 640
94.65 103.5 94.93 640
95.19 102 95.45 640
95.72 102 95.98 680
96.23 100.5 96.48 680
96.74 100.5 96.99 680
97.24 99 97.49 680
97.75 99 98.01 680
98.27 99 98.53 680
98.8 99 99.05 680
99.33 99 99.58 680
99.83 97.5 100.1 640
100.36 97.5 100.62 680
100.88 97.5 101.15 680
101.41 97.5 101.67 680
101.92 97.5 102.17 680
102.42 97.5 102.68 680
102.95 97.5 103.2 680
103.46 96 103.73 680
103.98 96 104.24 640
104.51 96 104.76 640
105.02 96 105.29 680
105.54 96 105.8 680
106.07 96 106.33 640
106.59 96 106.84 680
107.1 96 107.36 680
107.63 96 107.88 680
108.14 96 108.41 680
108.66 94.5 108.92 680
109.18 94.5 109.45 640
109.71 94.5 109.97 640
110.22 94.5 110.48 640
110.76 94.5 111.02 640
111.29 94.5 111.54 640
111.8 94.5 112.07 680
112.34 94.5 112.6 680
112.86 94.5 113.12 680
113.39 94.5 113.64 680
113.89 94.5 114.14 680
114.43 94.5 114.69 680
114.94 94.5 115.2 680
115.45 94.5 115.72 680
115.98 94.5 116.22 640
116.48 94.5 116.72 640
117 94.5 117.26 680
117.52 94.5 117.78 680
118.04 94.5 118.31 680
118.57 94.5 118.82 680
119.08 94.5 119.36 680
119.63 94.5 119.88 680
120.15 94.5 120.4 680
120.66 94.5 120.9 680
121.15 94.5 121.4 680
121.67 94.5 121.92 680

jcman

But then again I never had to, might give it a try though just to see if the fluctuations are the same.

At this point without any new cel codes you should be good.

AudiBruceH

Still getting the same cel code unfortunately. Must come on when it hits a certain temp low or high? Thinking of testing the voltage coming to the sensor from the ECU just for "fun". My issues are similar to this one but yet a little more consistant.

https://www.audiworld.com/forums/sho....php?t=2809026


Wife is looking at new cars, I better get it fixed soon!

jcman

The only values that don't look good are:
55.64 118.5 55.91 3240
56.16 120 56.42 3240

118c + 244f
120c = 248f

That seems to be out of range IMO, makes one wonder what the water pump is not doing at that RPM

AudiBruceH

Not sure how to check the water pump for flow - no weird noises or leaks. New pump at 145k and it has 167k now. It's just strange that the cluster gauge doesn't move when all this is happening. Is it just really slow reacting? Sometimes it will show 120c for a minute or so but the dash gauge is still in the middle. What would make the temp drop so drastically when I let off the gas and let it idle again. At 77 seconds it's down at 66c from 120c. Think erratic coolant flow would do this? Can't wait to figure this out! Thanks for help by the way, nice to have another helping me troubleshoot.

jcman

Well that pump ain't been around the block yet.

Bruce really I can't answer the reaction times of the sensor in correlation to the gauge, I do know that some impellers on our pumps are plastic and some are metal, just shooting trouble with wide eyes

AudiBruceH

I can't remember what kind I installed, think it was the metal variety. Just for fun, after letting it cool back down I logged the ecu temp warming up at idle (not going to post a 10 minute log) but basically it warmed up in nice 1.5 degree intervals until it hit about 115c. Then it fluctuated from 100 to 130, mostly hovering around 110c. Does kind of seem like a flow issue perhaps since when rev the engine the temperature starts to vary more. Maybe the impeller is slipping or ? Maybe it's time to tear it down for piece of mind. Running out of other ideas. Least I could rule it out mechanical failures. Maybe replace the thermostat while I have it apart at a minimum if the pump still looks good. Thanks-

Bruce

jcman

A few members are reading this too and I might be missing something here before you tear into a pump inspection, getting late and I'm turning in.


Tomorrow' replies might chime on in with a new answer.