What is causing an intermittent squealing noise from my 1998 Vauxhall Corsa?

My 1998 Vauxhall Corsa 1.6 petrol has started making an intermittent squealing noise. If I switch the air conditioning on then the noise goes away completely, but when I switch it off the noise comes back...

What's the difference between belt-driven and chain-driven cam shafts?

Please could you explain what differences there are between belt driven and chain driven cam shafts? Is one more fuel efficient, less noisy, more reliable and costly than the other? What makes one engine...

Would you recommend a 2006 KIA Sportage to drive from the UK to Portugal?

I'm thinking of buying a 2006 KIA Sportage automatic diesel (2-litre 4x4) with 49,000 miles on the clock, with a view to driving to Portugal from Dover. Is there anything I should look out for? Does this...