# Help..... 1.8t running very rough at idle, replaced much to no avail......



## J.schaef (Jun 22, 2012)

2002 Jetta 1.8t. 122k miles. Replaced timing belt, water pump, tensioner, idler pully (checked timing as well, is dead on)

Replaced throttle body, no change.

Replaced spark plugs, didn't find any vacuum leaks (going to pressure test today)

Tried replacing coil packs... No change.

Replaced Camshaft position sensor, no change. 

Car seems to run great over 2000RPM, but will not idle. 

Autoscan seems to lead me in 10 different directions. Replacing fuel filter today. Please help.

Here is the first autoscan (throttle body was out of the car)

Thursday,20,September,2012,18:14:02:55851
VCDS Version: Release 11.11.4
Data version: 20120807


Chassis Type: 9M - VW Jetta IV
Scan: 01 02 03 08 09 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57
75 76

VIN: 3VWSE69M42M080838 Mileage: 196730km/122242miles
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Address 01: Engine Labels: 06A-906-032-AWP.lbl
Part No: 06A 906 032 LQ
Component: 1.8L R4/5VT G 0007 
Coding: 07550
Shop #: WSC 23328 
VCID: 78FF5D43580960D8195
3VWSE69M42M080838 VWZ7Z0A4057787

6 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected 
P0300 - 35-00 - 
16685 - Cylinder 1 
P0301 - 35-00 - Misfire Detected
16687 - Cylinder 3 
P0303 - 35-00 - Misfire Detected
17951 - Angle Sensor 1 for Throttle Actuator (G187) 
P1543 - 35-00 - Signal too Small
17580 - Angle Sensor 2 for Throttle Actuator (G188) Signal too Low 
P1172 - 35-00 - 
17987 - Throttle Actuator (J338) 
P1579 - 35-00 - Adaptation Not Started
Readiness: 0110 1101

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Address 02: Auto Trans Labels: 09A-927-750.lbl
Part No: 09A 927 750 T
Component: AG5 Getriebe 09A 0162 
VCID: 3C7781532CB18CF83DD

3 Faults Found:
01166 - Engine Torque Signal 
16-00 - Signal Outside Specifications
00526 - Brake Light Switch-F 
28-10 - Short to Plus - Intermittent
01045 - Tiptronic Switch (F189) 
27-10 - Implausible Signal - Intermittent

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Address 03: ABS Brakes Labels: 1C0-907-37x-ASR.lbl
Part No: 1C0 907 379 K
Component: ASR FRONT MK60 0103 
Coding: 0018945
Shop #: WSC 00066 000 00000
VCID: 326BAF6BAEF54A88E71

1 Fault Found:
01314 - Engine Control Module 
013 - Check DTC Memory

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Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 6Q0 909 605 F
Component: 04 AIRBAG VW6 0202 0004 
Coding: 12340
Shop #: WSC 00066 
VCID: 3A7B874B2685B2C82F1

1 Fault Found:
00532 - Supply Voltage B+ 
07-10 - Signal too Low - Intermittent

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Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J0 920 906 N
Component: KOMBI+WEGFAHRSP VDO V59 
Coding: 07234
Shop #: WSC 00000 
VCID: 3365AA6F01EF4380EC7
3VWSE69M42M080838 VWZ7Z0A4057787

No fault code found.

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Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901 
Component: Gateway KCAN 0001 
Coding: 00006
Shop #: WSC 00066 
VCID: F0EFE563B079B898515

No fault code found.

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Address 46: Central Conv. Labels: 1C0-959-799.lbl
Part No: 1C0 959 799 C
Component: 1H Komfortger·t HLO 0003 
Coding: 00258
Shop #: WSC 00066 
VCID: 377D9E7F1597AFA0D0F

Subsystem 1 - Part No: 1C1959801A
Component: 1H Tırsteuer.FS KLO 0002 

Subsystem 2 - Part No: 1C1959802A
Component: 1H Tırsteuer.BF KLO 0002 

Subsystem 3 - Part No: 1C0959811A
Component: 1H Tırsteuer.HL KLO 0002 

Subsystem 4 - Part No: 1C0959812A
Component: 1H Tırsteuer.HR KLO 0002 

No fault code found.

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Address 56: Radio Labels: 3B7-035-1xx-56.lbl
Part No: 3B7 035 180 
Component: Radio NP2 0005 
Coding: 00031
Shop #: WSC 00066 
VCID: DDB1ACD757EB25F0EA3

No fault code found.

End ---------------------------------------------------------------------


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## J.schaef (Jun 22, 2012)

These are the codes I am currently getting from the ECM

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Address 01: Engine Labels: 06A-906-032-AWP.lbl
Control Module Part Number: 06A 906 032 LQ
Component and/or Version: 1.8L R4/5VT G 0007
Software Coding: 07550
Work Shop Code: WSC 23328 
Additional Info: 3VWSE69M42M080838 VWZ7Z0A4057787
VCID: 78FF5D43580960D8195
13 Faults Found:

17972 - Throttle Actuator (J338) 
P1564 - 35-10 - Under-Voltage during Basic Setting - Intermittent
17951 - Angle Sensor 1 for Throttle Actuator (G187) 
P1543 - 35-10 - Signal too Small - Intermittent
17580 - Angle Sensor 2 for Throttle Actuator (G188) Signal too Low 
P1172 - 35-10 - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected 
P0300 - 35-00 - 
16685 - Cylinder 1 
P0301 - 35-00 - Misfire Detected
16687 - Cylinder 3 
P0303 - 35-00 - Misfire Detected
16486 - Mass Air Flow Sensor (G70) 
P0102 - 35-10 - Signal too Low - Intermittent
18032 - MIL Request Signal Active (Check TCM for errors too!) 
P1624 - 35-00 - 
16688 - Cylinder 4 
P0304 - 35-00 - Misfire Detected
16686 - Cylinder 2 
P0302 - 35-00 - Misfire Detected
17763 - Cylinder 1 Ignition Circuit 
P1355 - 35-10 - Open Circuit - Intermittent
17766 - Cylinder 2 Ignition Circuit 
P1358 - 35-10 - Open Circuit - Intermittent
17769 - Cylinder 3 Ignition Circuit 
P1361 - 35-10 - Open Circuit - Intermittent

Readiness: 0110 1101


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## BassNotes (Mar 16, 2005)

Clear the fault codes and run a throttle body adaptation.


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## Freddy24 (Oct 16, 2011)

BassNotes said:


> Clear the fault codes and run a throttle body adaptation.


:thumbup:


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## J.schaef (Jun 22, 2012)

Ran a throttle body adaptation. No change.

Car is trying to idle around 950rpm.

Runs very rough. Feels like its only firing on 2 cylinders. Replaced fuel filter today. No change.

Could it just be bad gas? There were a few gas stations around my area that recently went through some gas issues..... At this point I am just searching.


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## Vegeta Gti (Feb 13, 2003)

unplug your MAF and drive around, tested/checked your front O2? what are your plugs gaps? how is the front O2 wiring? what is wired into the car..aftermarket stereo,etc?


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## J.schaef (Jun 22, 2012)

Tried driving with the MAF unplugged. No change. 

O2 sensor wiring is good. Will check the front O2 sensor now. Plugs are gapped at .032

Car is totally stock. No aftermarket anything.


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## Freddy24 (Oct 16, 2011)

J.schaef said:


> Tried driving with the MAF unplugged. No change.
> 
> O2 sensor wiring is good. Will check the front O2 sensor now. Plugs are gapped at .032
> 
> Car is totally stock. No aftermarket anything.


Maf could be bad


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## J.schaef (Jun 22, 2012)

Cleaned MAF, no change. Will try a known good MAF.


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## Krash64 (Sep 23, 2012)

Well this probably does not help but it looks like you are having some very similar problems as I am, codes are very similar also. I have been working on this problem for 2 months or more now with no resolve.

Look at my post; http://forums.vwvortex.com/showthre...Troubleshooting-help.&p=79079252#post79079252

Maybe we can compare notes...


K


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## 1fast2liter (Apr 4, 2005)

try cleaning the throttle body. also do you ave te updated coolant temp sensor?


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## J.schaef (Jun 22, 2012)

1fast2liter said:


> try cleaning the throttle body. also do you ave te updated coolant temp sensor?


Throttle body is new. Ran TBA with no change.

Will check the coolant temp sensor tomorrow, see if it is the updated one. I am at a total loss. Inspected the vacuum system. Replaced the 2 way valve, and 2 check valves. Found 2 fairly large leaks.

Fixed all vacuum issues I found, no change.


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## 1fast2liter (Apr 4, 2005)

is this all the time or just on start up r when ever car is left ti idle?


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## J.schaef (Jun 22, 2012)

It is all the time at idle.


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## BRES (Jul 24, 2009)

I had bouncy idle problems and mk6 coils fixed that. 


Sent from iPhone 4S.


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## VWBugman00 (Mar 17, 2009)

BRES said:


> I had bouncy idle problems and mk6 coils fixed that.
> 
> 
> Sent from iPhone 4S.


Mk5's will work too. And they're about $25 each at autozone with a year warranty.


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## J.schaef (Jun 22, 2012)

I tried 2 sets of new coils, both provided no change.


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## Slimjimmn (Apr 8, 2006)

Is your coil pack harness cracked? Do a search

Also have you done A COMPRESSION test?


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## groggory (Apr 21, 2003)

Sounds like you need to check all your positive and ground terminals throughout the car.

There is a grounding section of the FAQ that details all the points.

Please check your grounds with a voltmeter and keep an accurate log of what you checked and what voltage you read. Post up your exact results.


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## livef4st (Aug 15, 2012)

Glad to see a full scan. :thumbup:

What does measure block 32 say?

also, measuring blocks 15 and 16 at idle.


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## J.schaef (Jun 22, 2012)

Slimjimmn said:


> Is your coil pack harness cracked? Do a search
> 
> Also have you done A COMPRESSION test?


I searched cracked coil pack harness, I will investigate that if nothing else solves the problem. It seems to have just suddenly started about 2 weeks ago, for no apparent reason.
Yes, compression is high and even across all 4.


groggory said:


> Sounds like you need to check all your positive and ground terminals throughout the car.
> 
> There is a grounding section of the FAQ that details all the points.
> 
> Please check your grounds with a voltmeter and keep an accurate log of what you checked and what voltage you read. Post up your exact results.


Will check my grounds, log my results today and report back.



livef4st said:


> Glad to see a full scan. :thumbup:
> 
> What does measure block 32 say?
> 
> also, measuring blocks 15 and 16 at idle.


Will check these today as well. 

Thanks for your help and suggestions everyone.


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## VW1990CORRADO (Sep 30, 2000)

same issue on a friends 04.5 gli


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## Slimjimmn (Apr 8, 2006)

I just replaced my worn out cracked coil harness and its like night/day difference. :beer:


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## radlynx (Jan 4, 2007)

did you try cleaning the MAP sensor and the intercooler?



J.schaef said:


> Ran a throttle body adaptation. No change.
> 
> Car is trying to idle around 950rpm.
> 
> ...


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## JColleran1991 (Apr 21, 2012)

Vegeta Gti said:


> unplug your MAF and drive around, tested/checked your front O2? what are your plugs gaps? how is the front O2 wiring? what is wired into the car..aftermarket stereo,etc?


Sorry to threadjack, but why did you ask if the OP has an aftermarket stereo? I didn't realize that can make a difference in an idle. The idle on mine is a little rougher than I think it should be and I have an aftermarket stereo, amp, sub, bi-xenons, and an alarm with remote start. Could any of these factors be causing my rough idle?


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## rnorton1431 (Aug 30, 2012)

I have an 01 gti, its awd, i noticed a few of your codes are similar to mine, i was having an awful hot start problem and slight cold start prob, i replaced the cts and it hasnt had a problem since, i have cleared all my codes except for 3 that you have also, random misfire and cylinder 1 and 2 misfire. as it has been getting freezing temps in mornings my gti dies on initial start up and runs rough as hell on second. i just recently had the recall serviced on the coils, didnt fix a thing. im fixing to replace the wiring harness all together to see if it fixes. BUT.. back to my cold start problem, i am almost certain it has to do with my SAI, because on in morning, and when i leave work, the SAIP gets LOUD. i have yet to check, but i have got to have a leak in one of the 2 hoses, one is 90 and one is 145. cant remember if its hose to combi or air box thats so high. but, what i was getting to is my car has a rough idle, runs fine at 1000+ rpms, but is soon as it hits 900 its rough, cold or warm. i dont think the SAI would be a possible cause for the rough idle after engine is warm since its function is for cold start ups, but a guy at the dealership told me they do kick on time to time. i am going to take his advice for a temp fix first and put some heavy duty shrink tubing on the hose wherever i find my leak when i look and see what it does.


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## kelseymarie09 (Nov 21, 2012)

Just wondering if you have found the issue with your 1.8. I have the same motor in my passat with the same problems at 122K miles.


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## memo_gli (Sep 8, 2013)

And resolved this problem? 
I have this same problem misfire cylinder 3 on my Gli 04


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## sleepy1.8t (Sep 5, 2013)

JColleran1991 said:


> Sorry to threadjack, but why did you ask if the OP has an aftermarket stereo? I didn't realize that can make a difference in an idle. The idle on mine is a little rougher than I think it should be and I have an aftermarket stereo, amp, sub, bi-xenons, and an alarm with remote start. Could any of these factors be causing my rough idle?


he's asking because if any of the wiring was shoddy/half-assed it could contribute to the errors that are all over the place on OP's car


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## gli87jetta (Nov 26, 2001)

*Bump*

Hey OP. Did you ever figure this out??? I have a very similar issue. Mine went from occasionally car will die (see thread) to a very rough start that occurred for the first time in months! A few months ago per my thread I had my car stall out and hesitate really bad like it was damaged or running on a few cylinders.

Since the car was throwing this code I had my mechanic replace the speed sensor in hopes it would prevent the nasty stalling I would occasionally get when at stop lights.
16705 - Engine Speed Sensor (G28)
P0321 - 35-10 - Implausible Signal - Intermittent

This code still isn't coming up so that's good. But when i started my car this past Sunday it sounded like this guys 1.8t bug in the video!
https://www.youtube.com/watch?v=qjUOLY86L-M&feature=g-upl

My idle fluctuates a little and goes between about 680-740 when watching it with VAG-COM. I was thinking of replacing the coils but they are probably fine. They were done under a recall back in 07 I think so I have over 100k on them. But I don't throw any mis-fire codes and not sure if I should bother replacing them? Anyone know of a good way to test the coils? I was also thinking of looking into the cracked coil pack issue people mentioned. Is that easy to track down? 

I'm going to clean my MAF next to see if that helps stabilize the idle. Either way, I'm hoping to get this figured out soon. I hope it's not something with my APR load on my ECU. I've been meaning to go with a dedicated Frankenturbo tune so I might end up trying that as well. Thanks for any ideas. I'm pretty sure all my + and - ground(s) are good. 

Other things recently done/replaced. New fuel pump installed by dealer, New Fuel Filter. As mentioned, new crankshaft/speed position sensor, New MAP/Boost Sensor. Plugs are new stock plugs left at default gap. I think they are about .30 gap and I'm debating on changing them to .28 to see if that helps.


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