Hi,
Help Me please! My A6 Q 3.0 (45K - serviced properly) suddenly threw the "Check Engine" light at me. I realised the engine was shaking little unusually. It happened all of a shudden today evening. I had driven it pretty well the day before. When I started the car today, it was fine, ran for just 5 minutes and then started shaking (not very bad, but bad). I stopped the car and parked it to take it to the Service Center tomorrow morning.

Please help me with probable causes so that I can be prepared for tomorrows interaction at service center.

Regards

 

Sounds like a miss upon warming up or after a certain time running. My best guess would be a coilpack or sparkplug. Does the shaking go away when you give it a little gas? At worst I would say engine mount.

Your car is a 2002 right?

 

Thanks for your response. My A6 is 2003. I am in VA, and weather has suddenly cold (38F). The 40K service was done last winter and spark plugs changed. Engine mount does not seem a prob. as i had checked it 4 months back as part of service. The shaking do reduce on racing up the Car or increase of gas.
Any suggestios with above facts please?

 

It could still be the spark plug. Simple enough to pull each and make sure one isn't dirty or not gapped correctly. The other things I would check are the spark plug wires. Check the resistance of each of them and make sure they are all firmly connected.

In this order...

Wires connected firmly (can do while car is running...just push on each)
Wires resistance
plugs dirty
gapped correctly


These are of coarse the easy things to check and you should definetly check these first before you start tearing into the electronics.

The other (and most likely) possibility is that a coilpack is dead.

The way I've always check is by simply pulling each plug and holding it (by the insulated wire and not touching the car) next to the block while a friend turns a few cranks. If you see blue spark the coil is fine, if you see yellow or no spark then the coil is dead. Replace and your golden.


The other way (and I havn't tried this one) is as follows...
To check the coilpack ..just get a test light ground it some where on the block then press the the test light on the head of each wire at the coilpack.. you should hear a change in the way the car idles..if you get to one of the wires and the idle does not change.. that is the cylinder that is giving you the problem.

 

Thanks for the reply again. I will check in the line you have suggested and post the information.

 

I would start by checking the coils. They are usually the casue of a misfire.

 

It was indeed ignitioncoils. I have given it to the local Audi for the same. They have quoted 180 with service charges. Somehow feel it is little higher side, but can't help it as I have to get it done ASAP to handle committments for the holiday shopping.
Many thanks to all for the responses.

 

That sounds about right. Actually not bad at all. Real easy procedure swapping them so an hours labor plus parts.

 

Coil pack charge are typically $40-45 for the part and an hour labor, no more. They are covered under warranty if you have one. If not, you'll save $ by taking it to an indy shop.. my two shops charge 75 and 95/hours. Audi was a ot more.