car will idle from about 1000rpm and drop quickly to about 400rpm.
only happens when cold
takes about 2-3 minutes to heat up a little and then will idle normally
can sometimes stall
the throttle body has been cleaned
the water temperature sensor has been replaced recently but didn't fix the idling issue
the engine management light is on
car runs and starts perfect when hot
Does anyone know what is going on here?
mk5 1.4 16v rough idle from cold
mk5 1.4 16v rough idle from cold
Vag com it, could be thermostat.
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gallienfan
- New
- Posts: 2
- Joined: Sun Dec 04, 2011 7:31 pm
Re: mk5 1.4 16v rough idle from cold
Mine had the same issues, not wanting to start from cold, idling rough, dying at traffic lights etc. I tried cleaning the tb, temp sensor new plugs, dizzy etc nothing helped. Then i was under the bonnet while it was dark cos it wouldnt start, my brother turned the engine over and i could see a light flashing from the ignition coil..... got a new one for about £30 from GSF and now i have no running or starting problems at all. This might not be your problem but it worked for me and its probably more likely this than the thermostat in my humble opinion! 
Re: mk5 1.4 16v rough idle from cold
ok so heres the diag codes,
I also ran a compression test and one of the cylinders is a little lower than the rest, cant remember the exact compression. Its using water to so I guess the cylinder head gasket is on the way out.
what do you all think?
VCDS-Lite Version: Release 1.1
Thursday, 06 October 2011, 20:49:56.
Control Module Part Number: 036 906 034 D
Component and/or Version: MARELLI 4LV 3458
Software Coding: 00031
Work Shop Code: WSC 00788
VCID: 13593C4F727B
4 Faults Found:
17559 - Long Term Fuel Trim Additive Air; Bank 1; Range 1: System too Lean
P1151 - 35-10 - - - Intermittent
17953 - Shareware Version. To Decode all DTCs
P1545 - 35-10 - Please Register/Activate - Intermittent
17972 - Shareware Version. To Decode all DTCs
P1564 - 35-10 - Please Register/Activate - Intermittent
17589 - Linear O2 Sensor; Reference Voltage: Open Circuit
P1181 - 35-10 - - - Intermittent
I also ran a compression test and one of the cylinders is a little lower than the rest, cant remember the exact compression. Its using water to so I guess the cylinder head gasket is on the way out.
what do you all think?
VCDS-Lite Version: Release 1.1
Thursday, 06 October 2011, 20:49:56.
Control Module Part Number: 036 906 034 D
Component and/or Version: MARELLI 4LV 3458
Software Coding: 00031
Work Shop Code: WSC 00788
VCID: 13593C4F727B
4 Faults Found:
17559 - Long Term Fuel Trim Additive Air; Bank 1; Range 1: System too Lean
P1151 - 35-10 - - - Intermittent
17953 - Shareware Version. To Decode all DTCs
P1545 - 35-10 - Please Register/Activate - Intermittent
17972 - Shareware Version. To Decode all DTCs
P1564 - 35-10 - Please Register/Activate - Intermittent
17589 - Linear O2 Sensor; Reference Voltage: Open Circuit
P1181 - 35-10 - - - Intermittent
Re: mk5 1.4 16v rough idle from cold
There's more chance of me becoming queen than the thermostat being the cause of your problem