Hello everybody, 1st post on the forum!
I have a 2007 1.1 CZ1 Colt, which is great, apart from a couple of worries:

Firstly, just sometimes after the car has been running a while and has warmed up, under acceleration, the engine develops a 'rorty' roaring noise, partly hiding the 'zingy wheeze' which I am used to. (Sorry for the descriptions!)
Also, only really on the couple of cold mornings we've had recently, upon starting, the engine clatters like an old diesel for the first 5 seconds or so before settling down, and is also slighly clattery on moving off just for the first minute or two. Is this possibly the oil in the engine not being ready, or does the chain cam slacken when cold?
If the second problem is just one of those things than I can live with that, but the first noise is a small worry. It doesn't really effect performance, but is just a worry by the fact that many times it isn't there.

Could anyone give me any hints on what might be happening?

Thanks,
Dave

First of all it's a 3-cylinder engine which is running not as smooth as a 4 cylinder engine.

As an idea you could mount the noise absorber mats from the diesel engine.
This will help especially for the high frequency noise.

ALexander