Diagnostic light flashing - suggestions?

[jayblue]

I was driving the car back home this afternoon (LCR) and when i gave it full throttle in second gear the car juddered almost like the TC was holding it back as it does in the wet then the engine diagnostic light kept flashing. This continued only when i used full throttle from 3k rpm +. Having done a search various ideas seem to be thrown around on this one - coil packs, a bad earth, spark plugs, coolant temp sensor, cat gone etc.

My car has done 36,000 miles and has had a forge 007 d/v fitted since 32k. One of my mate said to check the hoses to that first and that the piston is moving smoothly? As far as i know the car hasnt had new coil packs, are they a likely suspect at this mileage and if so will a particular code come up when i vag com it? The light isnt lit permanantly on the dash and i only drove it for 2 miles after it flashed - havent moved it since.

One know problem i have is on cold mornings the coolant light stays lit and i get 3 warning beeps, but only on cold mornings so i havent had it replaced yet, i have checked the level of coolant frequently and it is fine. Any help will be appreciated.

 

[skahigh]

the best thing you can do is vag-com it (if you have it) because people can speculate all day about various possible causes and none of them will bring you any nearer to knowing what is wrong.

The control modules store intermittent fault codes so even if the light isnt on all the time the fault code should still be stored. I wouldnt have thoughts the pistons would be a problem at that mileage.....I certainly hope not as my car has done 39k!!!!

My money is on coolant sensor (mine has just this week gone) and/or speed sensor.

 

[jayblue]

Ok thanks - i have a friend who is going to vag com it for me so i will post the results here when he does. In any case i will now have the coolant sensor done and change the plugs as required for the 40k service.

 

[Stan 24v]

Sounds like coolant sensor. Theyre only about £20

 

[jayblue]

Just had it vag com'd and its coil pack 3 thats gone. No errors from the dodgy coolant sensor but getting that changed too now. Going to do all 4 coil packs as they from what ive seen on here they always all seem to go around the same time....

One point of interest though, my coil packs are push down fit, no screws on them. On my mates S3 they are screwed in. Why and whats the difference if any?

Also i'm going to do the spark plugs - any specific recommendations?