It does sound like your hamster has a cold (when hamsters get colds the symptoms are usually the same as those of a human's). Of course, I'm not a vet, but I can give you a few tips I learned from all the hamsters and mice I've kept...
If you have a cage with bars, keep it away from any drafty areas. Give him extra bedding (double the amount you usually give) and feed him little chunks of dry carrot or apple. This might help boost his immune system.
I must mention that I used to have several mice who constantly made grunting and snuffly sounds - it was just how they breathed and it never caused them any problems, so just observe your hamster's condition and see whether it is actually ill or whether it's just the way he is!
Hope this helped,