I have an Astra G 1.8 SRi and, although 9 years old now, it's only done 40,000 miles.
Over the last month or so I've noticed a ticking which has gradually got louder. It goes up and down with the revs, which leads me to think it might be the tappets. I've chucked a tub of Wynns Hydraulic Valve Lifter Treatment in but it hasn't quietened down at all (though its only been in a couple of days so maybe I'm jumping the gun).
Are my valves really likely to need replacing at such a low mileage?
My other thought is whether replacing the timing belt could have any effect - I have the car booked in for a replacement one next week (at 9 years old I thought I'd better not push my luck any further!!), but don't really understand how the engine works well enough to know if this could be a cause/solution.
So, to cut it short, what I'd like to know is:
1.) Are my valves likely to be worn at 40k?
2.) Is it possible that a new timing belt is going to stop the noise, or is that a mechanical impossibility?
The garage suggested that replacing the valves at the same time as the belt would be more cost effective if they need doing, but I don't want to do them if simply replacing the belt will sort the problem, or if there might be another cause.
Any advice would be massively appreciated.