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Matt
Matt, Mechanical Engineer
Category: Audi
Satisfied Customers: 21860
Experience:  BEng hons Mech engineering, in auto industry 22 years
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Every morning when I start my car the car shakes and judders

Customer Question

Every morning when I start my car the car shakes and judders for approx 20 seconds, then it goes back to normal. Sometimes it doesn't happen, and sometimes it worse than other times. Its a A1 Sportback S line 1.4 TFSI 185 PS S tronic 2013. It has only just reached 15000 miles. I had a coil pack changed in it approximately 2 months ago because the engine management light and emission light kept appearing.
I drive it approx 20 miles a day, and occasionally a long journey at the weekend.
Seems weird because its a new car, what do you suggest?
Submitted: 1 year ago.
Category: Audi
Expert:  Shantal-Mod replied 1 year ago.
Hello,
I'm Shantal and I'm a moderator for this topic.
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Customer: replied 1 year ago.
Hi.
I am still waiting for some help;
Thanks
Olly
Expert:  Matt replied 1 year ago.

Hello

This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;

Airflow meter

Crank position sensor

Cam position sensor

O2 sensor

Throttle position sensor

unplug each in turn and use some switch / contact cleaner spray on the pins to ensure its all grease / dirt free

Also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40

and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump

And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.

Check the resistance of the spark plug leads ( 13-15Kohm / metre) and replace if any doubt or high resistance - Also replace the spark plugs if any of them fail this checklist:

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

Also its worth checking that the electric pump that feeds the injectors is working correctly, it should run for a few seconds then switch off when you first turn the ignition on. If the connections to this are corroded or damaged then the pump could stop at any time. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse, ideally measure the voltage at the pump and check its getting 12V

Also check for exhaust leaks before the o2 sensor as if this has been experiencing an exhaust leak then it will have been running very rich as the sensor will see the extra air pulled in as fresh / lean fuelling and be adding fuel to compensate.

this can lead to catalyst failure as the extra fuel can re-light inside and melt the catalyst

Expert:  Matt replied 1 year ago.

Hi

do you still need help?

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