My 2003 Opel Agila 1.2 is making a very loud ticking noise when I start it up, and it doesn't sound right. It only ticks when idling and when I rev it, the ticking noise goes away. The car runs completely fine, but the noise is really annoying and I'm worried that it is something bad.
I had an oil change in December, and I have no warning lights. Also sometimes when I start the car up and the car revs itself up to about 1.2k at idle to warm the O2 sensors, the car judders and shakes, and the ticking noise is really bad. However when I rev it all of this goes away again, but this only happens about once a month.
I have a recording of the sound here. Sorry about the bumping around, I did it with my phone...
The recording is from inside the engine compartment, and you can hear the ticking noise.
Can anyone tell me if this noise is bad? Can I fix it?
MORE INFO: My engine is chain driven. There is no timing belt, there is a timing chain.
It's recently started doing it. I've done about 6000 miles since the oil change.