Hi there,
Just bought a 57 plate 2.0 TR Auris D4D second-hand, with 57,000 miles on the clock. Looks like a perfectly nice car so far, but one thing I have noticed is a distinct rattling noise from the engine under acceleration. It sounds a lot like the pinking you'd get on a mistimed petrol engine. The only odd thing is that I'm 99% sure it wasn't there when we test-drove it. It's pretty noticeable, after all.
A bit of googling around suggests it might be a worn injector causing a bit of predetonation. Does that sound plausible? And if it is that, how big a problem is it? Will it need fixing immediately or can we wait? And does anyone know roughly how much it'll cost to get it fixed? I have a 12-month dealer warranty that pays the first £500, for what that's worth.
The other option is that it's related to the air filter - it got RAC tested before we bought it and apparently the chap who did it made some kind of mistake with the air filter (I don't have the exact details to hand), but 1) it's apparently now been fixed and 2) I'm not really sure how a filter problem could cause this in the first place. Any help much appreciated!
edit: the rattling starts at about 1400 rpm. I can't tell if it carries on at high revs because the engine roar tends to overwhelm it, but it's still noticeable around 2000. And it only happens under acceleration - it's perfectly smooth when it's cruising.