Re: Considering a 166
Had a quick look at the car advertised, and it is good value for 4.8K. The most important thing with Alfa's in my opinion is a solid service history. Specifically look for evidence of timing belt change every 50K, and general records of regualr servicing.
Another couple of things to check are:
1) Hot Idle - Run the car untill it gets to operating temperature (90C), stop the car and check over a period of a few minutes that the car ildes smoothly just below 1000rpm. If it's not running smoothly demand that the problem is resolved before you buy it. You can take a chance that it could be a sticking butterfly value or a faulty air flow regulator, which are easy to resolve.....but you never know.
2) Check that the ICS is working properly and that you have the relavent code for it as they are expensive to replace.
3) The larger engined 166's are exceptionally front heavy so get the front suspension & wishbone assembly checked, an obvious sign of a problem is uneven wear in the front tyres.
Other than that it's the usual things to check when buying a second hand car, Shut Lines, electrics (watch for tired seat and window motors)...etc.