[Q] Engine Oil Leaks?

Hi,

My 240sx S13 car went for the six-monthly roadworthiness test earlier 
this week and it passed according to the service man as "all okay", but 
on reading the printed report later I saw it said "Engine oil leaks 
require attention soon".

Oil level seems fine after doing a few driving tests and checks.

Anyone know what symptoms to look for / places to check?

There was a bit of oil residue on top of the engine and in front of the 
radiator. Cleaning that off before driving a test run didn't seem to 
make it reappear in any great amount, if at all. The insulation on the 
underside of the hood does seem to be flaking in one or two places 
though and a possible oil stain.

Potentially it could be something to do with the cam belt replacement 
that was done a couple of months ago, but I haven't been driving the 
car much since then. Possible it's just some spilt oil during that 
repair or something needs re-checking.

Thanks.