I have LOTS of precautions and I think studded tires should be allowable.Talking about Mountain Biking on frozen lakes and such here.
Sure it is OK that is until it breaks leaves you stranded beside the road!!
I'd say what you really need is a new auto mechanic.
headache forced air central heating gas leak check
i would say the noise would be coming from the head, possibly your roller rockers or your cam, and is quiet common in cars with alot of miles and from about 1988 - 1996 models cause your timing chain isn't a chain, it a high-tensile rubber with teeth on the inside, and i find it hard to believe a mechanic said that unless he was the apprentice, engines can be alil greasy but there shouldn't be oil all over it, i would suggest to regularly change your oil and ride it out till your engine dies, it will be worth more to overhaul your head then what the engines worth p.s. If your timing belt is slight out of sync or breaks it will cost you an engine, the timing belt keeps the internals functions in perfect sync and if it ain't perfect it will bend valves possibly bend the cam or crankshaft, piston head damage, etc, etc
