98VW NB 2.0L gasoline engine, overheating

Hi, everyone.
Temp light came on, I stopped and check the cooling system. Upper rad hose is warm but the lower rad hose is cold. The radiator is cold and the fans are not working. Oil level OK , oil color on the dipstick OK but the oil cap has a white color deposits, looks like oil mix with antifreze. I replaced the thermostat but nothing changed. Do you suspect the water pump and/ or the cylinder head gasket? The vehicle has 108,000miles and probably never had the timing belt and water pump replaced.
Thank you beforehand.

I'm no expert but the indications are that the water pump is 'finis'. The white stuff on the oilcap can indicate a blown head gasket but can also be normal for a car driven short distances in a cold country unlike NQ. With a blown headgasket you should have other indications like blowing coolant out the overflow tank or steam out the exhaust and missing/lack of power. You sound like you may be lucky - you stopped immediately and inspected the vitals. If it was me I'd put a new waterpump in and a new timing belt. I'd also screw out the sparkplugs and see how they look. Keep that rabbits foot in your pocket and hopefully you'll be home and hosed like a sure thing in the Melbourne Cup.

2.0's have plastic water pump impellars... dont drive with it like that. research locally or internet for a water pump with metal impellars. Might as well change the timing belt and tensioner...