Edited by V4 Heaven on 10/01/2013 at 14:16

The 1.2 and 1.4 petrol engines in the Corsa D (current shape) cars do make a characteristic ticking sound at idle, and it can come and go, irrespective of whether the car is hot or cold.

We recently bought a 2010 1.2 (82bhp model) with 15,000 miles up, and the ticking at idle is noticeable from inside the car, but oddly not when standing outside the car.

I was going to raise it with the supplying Vx dealer, but the Corsa 1.2 courtesy car I had while having a warranty job done also made the same ticking sound at idle. I've since driven another 1.2 petrol Corsa and that one 'ticked' at idle too.

As all of these cars are relatively low mileage, I reckon it's just a quirk of the engine type.

Re. the mayonnaise on the oil filler cap, it's common with Corsa petrols. They really do "all do that, sir". If the car's been on the dealer's forecourt for any length of time it will have had lots of cold starts while being shunted from place to place, which won't help.

The ticking could be the injectors. The injectors on my vans HDi motor tick quite loudly - it's because they inject at very high pressure compared to petrol injectors.

Mayo may be due to condensation and short journeys, but also may be symptomatic of a head gasket problem. Was there any mayo in the coolant (or brown deposits on the inside of the expansion tank) which might support that theory?

If it's likely to be down to condensation, I would ask the supplier to perform a full oil change with a proper oil flush. When you pick it up the oil should then look clean and golden on the dipper.

And once you've bought it, follow HJs advice re oil change frequency.

Well what can I suggest now.

Don't buy from a dealer thats 2 grand off for starters.

Don't buy a car with a ticking engine. Must be worth 2 grand?

So you get a Corsa D for £2000. Change the oil, change it again, keep your fingers crossed.

You must use 5w30 synth, no other will do. Brand and car is unimportant as you're going to be changing every 1000, then 2000, then 3000 miles until the ticking stops.

Having said that, some engines will always tick a bit when cold, just make sure you're not buying a car where the services have been done at the minimum or less, and the oil changes neglected.

Otherwise you may find to your regret, as countless others have, that the last cylinder in the oil line has suffered some amount of oil starvation and has worn rings.

If you can manage 4 grand off, you can happily contemplate a new engine.