Need some advice from the more mechanically-minded members please.

In short, my car was garaged for just over a year up until a month ago. Since then I've changed the oil, oil filter, gearbox oil, clutch cable and exhaust from the cat back. I've never really worked on my cars prior to this past month, so it's been a steep learning curve and quite fun, if a little frustrating.

However, every so often the 'Autodiagnostics' light comes on and the engine sounds a little rough/hesistant and the engine is reasonably warm. It also sounds slightly rough starting, but no warning light. The rough starting appears worse now with the new exhaust (which is a cheapo Online Automtive jobby).

Here's what I'm thinking:

- Autodiagnostics implies a problem with ignition system, so that tells me that it could be a coil pack on the way out, or spark plugs need changing or an injector playing up.

- Rough starting may be consistent with the above - could it be that it's starting on 3 cylinders? It doesn't particularly struggle to start, just when it catches, car shakes a little - does this sound like starting on 3 cylinders or a misfire? (Excuse my ignorance if this should be obvious...)

What I plan to do:
- Compression test the cylinders
- Test various sensors according to the FAQ with my shiny new multimeter
- Change the spark plugs

Any opinions/advice will be welcome.

Cheers

________________________________________

Blaze 6
Keep It Standard

There is an easy way to check if it's one of the Coil Packs on the way out.

With the engine running, unplug each of the coil packs one at a time. If you remove a plug and the engine starts to struggle then that coil pack is working correctly. if you unplug one and there is no change in engine behaviour then you can be pretty certain that the coil pack is on the way out or is no longer working.

If the above doesn't make sense then let me know and I'll try and explain things a bit better.

It's a free check and you've got nothing to lose by doing it, so you may as well give it a go.

If you're not confident about doing it then I wouldn't try it.

TBH it's not that hard, you're not actually removing the Coil Pack, you are just unplugging the small plug on top of each of them.

You shouldn't have any problems with regards to getting an electric shock by doing the above, but as I say if you're not confident about doing it then I wouldn't risk it.