Weird, rough idle

[hilas07]

Hi,

Before i begin, i have tried using search and could not find anything matching.

I have an issue with my recently purchased 9n3 and would like to pick your brains before i get overwhelmed with possible issues.

I bought the car a month ago '06 9n3 64,000km, hadn't been serviced in 9000km (owner before last was quite good with services at VW and Germania Motors), i noticed a weird low idle and shake every 10-15 seconds and quite shaky

Last week i had the car serviced replacing air filter, spark plugs, oil, oil filter, fuel filter, brakes and the likes in the hope it would rectify the issue, but it still persists

Once moving the car drives quite well, only the idle that is the issue...

I must also mention it has (bought it with) an APR ECMS tune (weird idle is present throughout all 4 modes)

Any ideas? Injectors maybe?

Thanks in advance

[flat6]

Had a similar issue with my car a few months ago, I have the APR tune and noticed a weird idle at times, but mostly after a dodgy batch of optimax fuel..

Also if your car also got the polyurethane engine mount insert, you'll notice the rough idle heaps more, but its also possibly due to the fans kicking in adding strain to the electrical system, thus kicking the idle up

[noone]

mounts would be the 1st thing, but if it wasn't like that when you bought it, then likely not...

If you raise the RPM slightly, does the issue go away? You can adjust the idle if you know how.

I'm in St Leonards if you wanted to bring it over and I can see how it compares.

[hilas07]

Thanks for the responses guys!

Flat6 - I have been using V power.. But doesn't sound like the fan kicks in, just a constant dip in revs every 10-15 secs with a shake, never stalls though

Is that mount issue common?


Noone - It was definitely present when I bought it, I guess I just didn't look too far into it because I assumed/hoped the service would make it run smoother

Yep when I raise it to the 1k mark it is back to smooth again, but I'll have to manually hold it there... It wouldn't be as noticeable if it wasn't for the dip and shake... Idle adjustment sounds like a possible fix.. Thanks I am in Hurstville, I may look to see how difficult it is and if I have no luck, I'll pop round

I've also noticed a metal plate near the spare stating the car was recalled with a date on it (can't remember off the top of my head) do you guys know what the recall would've been for? Is it anything I should worry about?

Thanks again for the help guys!

[h100vw]

You should have it scanned for faults and with VCDS look at measuring blocks 032 and 111. Record those blocks for a minute at idle.

I suspect an air leak somewhere.

Gavin

[hilas07]

Thanks Gav!

I am pretty new to all this, is there anywhere that I can go to get it scanned without it being too costly?

[h100vw]

Thanks Gav!

I am pretty new to all this, is there anywhere that I can go to get it scanned without it being too costly?

Ben, Noone has a VCDS lead. There's also a thread I started a long while back that has a list of VCDS owners that will scan for beer/fun etc.

Gavin

[ProJulz]

Same thing happens with mine. Tends to be worse on a hot day, so I imagine it's to do with the fan. A bump in idle would work, it stops happening above 850 rpm anyway.

[hilas07]

Bit of an update, haven't had a chance to do a scan as yet but the lumpiness has been more persistent and seems to be around to stay, both hot and cold weather..

I noticed tonight raising the revs to 1100 at a standstill and the lumpiness was still present, the only thing I've changed in the past week or two was I as I added PD160 intake and 2nd hand K&N filter that had been cleaned by the previous owner, I am gathering MAF censor may need a clean as it could have sucked in some oil from the second hand filter?

Anyone have any ideas? I'll be interstate for the next couple days, just want to see how I should approach this when I return.. Could it need a retune from APR? Or just some sensors playing up?


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[h100vw]

Bit of an update, haven't had a chance to do a scan as yet but the lumpiness has been more persistent and seems to be around to stay, both hot and cold weather..

I noticed tonight raising the revs to 1100 at a standstill and the lumpiness was still present, the only thing I've changed in the past week or two was I as I added PD160 intake and 2nd hand K&N filter that had been cleaned by the previous owner, I am gathering MAF censor may need a clean as it could have sucked in some oil from the second hand filter?

Anyone have any ideas? I'll be interstate for the next couple days, just want to see how I should approach this when I return.. Could it need a retune from APR? Or just some sensors playing up?


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It will have nothing to do with the software. You are wasting your time doing anything before scanning it and checking those blocks 032 111.

Diagnose first, don't throw money at it.

Gavin

[hilas07]

It will have nothing to do with the software. You are wasting your time doing anything before scanning it and checking those blocks 032 111.

Diagnose first, don't throw money at it.

Gavin

So I finally had a chance to meet with zei20t and he was very helpful. We were able to replicate the issue and scan blocks 111 and 033 (tried 032 but nothing was happening). We put marks 1-4 where the lumpiness was most noticeable.

Let me know if you'd like a copy of the logs to make it a little easier to read, i can email it to you, cheers

Group A: '111 Group B: '028 Group C: '033
Lambda Lambda Lambda Lambda RPM Load Temperature Lambda Voltage Bin. Bits Bin. Bits
TIME TIME TIME
Marker STAMP % % % % STAMP /min % °C STAMP % V
0.3 0 0 -0.3 0 0.59 680 21.1 96 Test OFF 0.01 0.8 1.5
1.2 0 0 -0.3 0 1.49 760 20.3 96 Test OFF 0.9 2.3 1.62
2.1 0 0 -0.3 0 2.41 720 20.3 96 Test OFF 1.8 2.3 1.48
3.01 0 0 -0.3 0 3.31 720 19.5 96 Test OFF 2.71 1.6 1.58
3.91 0 0 -0.3 0 4.22 720 19.5 97 Test OFF 3.6 -0.8 1.52
4.82 0 0 -0.3 0 5.11 720 20.3 97 Test OFF 4.52 -1.6 1.52
5.73 0 0 -0.3 0 6.03 760 19.5 97 Test OFF 5.43 -1.6 1.52
6.63 0 0 -0.3 0 6.92 760 19.5 97 Test OFF 6.33 -1.6 1.52
7.53 0 0 -0.3 0 7.84 720 19.5 97 Test OFF 7.24 1.6 1.54
8.44 0 0 -0.3 0 8.74 720 19.5 97 Test OFF 8.14 1.6 1.52
9.35 0 0 -0.3 0 9.64 760 19.5 97 Test OFF 9.04 0.8 1.5
10.25 0 0 -0.3 0 10.56 720 19.5 97 Test OFF 9.95 0.8 1.54
11.16 0 0 -0.3 0 11.46 760 19.5 98 Test OFF 10.85 -1.6 1.54
12.06 0 0 -0.3 0 12.36 720 20.3 97 Test OFF 11.76 -2.3 1.52
12.97 0 0 -0.3 0 13.27 760 19.5 98 Test OFF 12.66 -2.3 1.52
13.86 0 0 -0.3 0 14.17 720 20.3 98 Test OFF 13.57 -2.3 1.54
14.77 0 0 -0.3 0 15.08 720 20.3 98 Test OFF 14.48 1.6 1.54
15.68 0 0 -0.3 0 15.98 720 21.1 98 Test OFF 15.38 1.6 1.52
1 16.59 0 0 -0.3 0 16.89 760 20.3 98 Test OFF 16.3 1.6 1.54
17.49 0 0 -0.3 0 17.8 720 19.5 98 Test OFF 17.19 2.3 1.52
18.4 0 0 -0.3 0 18.7 720 19.5 98 Test OFF 18.1 -1.6 1.5
19.3 0 0 -0.3 0 19.61 720 19.5 98 Test OFF 19 -2.3 1.54
20.2 0 0 -0.3 0 20.51 760 19.5 98 Test OFF 19.91 -2.3 1.5
21.12 0 0 -0.3 0 21.42 720 19.5 98 Test OFF 20.81 -2.3 1.52
22.02 0 0 -0.3 0 22.31 720 19.5 98 Test OFF 21.72 0.8 1.54
22.93 0 0 -0.3 0 23.23 760 19.5 98 Test OFF 22.62 0.8 1.52
23.83 0 0 -0.3 0 24.13 720 19.5 98 Test OFF 23.52 0.8 1.54
24.74 0 0 -0.3 0 25.03 720 19.5 98 Test OFF 24.43 1.6 1.54
25.63 0 0 -0.3 0 25.94 760 20.3 98 Test OFF 25.34 -1.6 1.52
26.55 0 0 -0.3 0 26.85 760 19.5 98 Test OFF 26.24 -2.3 1.52
27.44 0 0 -0.3 0 27.75 720 19.5 98 Test OFF 27.15 -2.3 1.54
28.36 0 0 -0.3 0 28.66 760 19.5 98 Test OFF 28.06 -1.6 1.5
29.26 0 0 -0.3 0 29.57 760 21.1 98 Test OFF 28.96 0.8 1.52
30.17 0 0 -0.3 0 30.47 720 19.5 98 Test OFF 29.87 1.6 1.54
31.07 0 0 -0.3 0 31.38 760 19.5 98 Test OFF 30.76 1.6 1.5
31.98 0 0 -0.3 0 32.27 720 19.5 98 Test OFF 31.68 1.6 1.54
32.88 0 0 -0.3 0 33.18 720 19.5 98 Test OFF 32.58 -1.6 1.54
33.78 0 0 -0.3 0 34.09 760 19.5 98 Test OFF 33.48 -1.6 1.54
34.68 0 0 -0.3 0 35 720 19.5 99 Test OFF 34.39 -1.6 1.5
35.6 0 0 -0.3 0 35.89 760 19.5 99 Test OFF 35.3 -1.6 1.52
36.51 0 0 -0.3 0 36.81 720 19.5 99 Test OFF 36.2 0.8 1.5
37.41 0 0 -0.3 0 37.71 760 19.5 99 Test OFF 37.11 0.8 1.52
38.32 0 0 -0.3 0 38.62 720 20.3 99 Test OFF 38.01 0.8 1.54
39.22 0 0 -0.3 0 39.52 760 19.5 99 Test OFF 38.92 0.8 1.54
40.13 0 0 -0.3 0 40.43 720 21.1 99 Test OFF 39.82 -1.6 1.54
2 41.03 0 0 -0.3 0 41.33 760 19.5 99 Test OFF 40.73 -1.6 1.6
41.93 0 0 -0.3 0 42.24 720 19.5 99 Test OFF 41.63 -1.6 1.5
42.84 0 0 -0.3 0 43.14 720 19.5 99 Test OFF 42.54 -2.3 1.48
43.75 0 0 -0.3 0 44.05 720 19.5 99 Test OFF 43.45 0.8 1.52
44.65 0 0 -0.3 0 44.94 720 19.5 99 Test OFF 44.35 0.8 1.5
45.56 0 0 -0.3 0 45.86 720 19.5 99 Test OFF 45.26 0.8 1.54
46.46 0 0 -0.3 0 46.76 720 19.5 99 Test OFF 46.16 0.8 1.54
47.37 0 0 -0.3 0 47.67 760 20.3 99 Test OFF 47.07 -2.3 1.54
3 48.27 0 0 -0.3 0 48.58 720 20.3 99 Test OFF 47.96 -1.6 1.54
4 49.17 0 0 -0.3 0 49.48 720 21.8 99 Test OFF 48.88 -1.6 1.54
50.08 0 0 -0.3 0 50.39 760 21.1 99 Test OFF 49.78 -2.3 1.48
50.98 0 0 -0.3 0 51.28 760 21.8 99 Test OFF 50.69 0.8 1.58
51.88 0 0 -0.3 0 52.2 720 23.3 99 Test OFF 51.59 1.6 1.56
52.8 0 0 -0.3 0 53.09 760 21.1 99 Test OFF 52.49 3.9 1.62
53.7 0 0 -0.3 0 54.03 720 21.1 99 Test OFF 53.4 2.3 1.44
54.71 0 0 -0.3 0 55 760 21.1 99 Test OFF 54.43 -0.8 1.54
55.61 0 0 -0.3 0 55.98 720 21.1 99 Test OFF 55.31 -0.8 1.5
56.53 0 0 -0.3 0 56.81 760 22.6 99 Test OFF 56.22 -1.6 1.54
57.42 0 0 -0.3 0 57.73 760 21.8 99 Test OFF 57.12 2.3 1.58
58.34 0 0 -0.3 0 58.62 760 20.3 99 Test OFF 58.03 2.3 1.5
59.24 0 0 -0.3 0 59.53 760 21.1 99 Test OFF 58.94 2.3 1.56
60.14 0 0 -0.3 0 60.43 720 21.8 99 Test OFF 59.84 2.3 1.54
61.05 0 0 -0.3 0 61.35 720 21.1 99 Test OFF 60.75 -1.6 1.5
61.95 0 0 -0.3 0 62.26 760 21.1 99 Test OFF 61.64 -1.6 1.56
62.85 0 0 -0.3 0 63.15 720 20.3 99 Test OFF 62.56 -2.3 1.48
63.76 0 0 -0.3 0 64.06 760 20.3 99 Test OFF 63.46 -2.3 1.5
64.67 0 0 -0.3 0 64.97 760 20.3 99 Test OFF 64.37 0 1.5
65.56 0 0 -0.3 0 65.87 720 21.1 99 Test OFF 65.27 0 1.52
66.48 0 0 -0.3 0 66.78 760 21.1 99 Test OFF 66.18 0 1.54
67.38 0 0 -0.3 0 67.68 720 21.1 99 Test OFF 67.07 0 1.54
68.29 0 0 -0.3 0 68.58 720 21.1 99 Test OFF 67.99 -2.3 1.56

[zei20t]

Without ripping too much off the engine; we also cleaned the throttle body. looked pretty good, but gave it a quick spray, a bit of oil came out, pretty normal IMO.

also removed 2 plugs (3&4) - there was a misfire on cylinder 3 - checked them and both were fine, also swapped coils 3 and 4 in case the problem moved.

Besides a boost/vacuum leak I wouldn't want to guess, maybe PCV or the crank-case ventilation?

Happy to do some more logging when you need it mate.

[hilas07]

Had a phone convo with Paul from Muller & Muller at Lakemba, few possible issues..

Going to swap the battery temporarily to distinguish if it is a battery/electrical issue, if not a possible Vacuum leak or injector issue.

Has anyone had any experience at this shop?

[noone]

really hard to read the data, better to make a spreadsheet and screen-cap so we can read it.

[hilas07]

Will try my best tomorrow to put a spreadsheet together from the original file..

Visited muller and muller and he had a look and did a quick scan.. Suggested more than likely coolant temperature sensor, roughly $200 to change the part. Anyone had any experience with this? Thanks in advance guys


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