make sure you're not on a wireless connection, they suck.
make sure your chords are plugged in firmly.
i had the same issue in about march, i had the router for like 2-3 years but sometimes randomly it'd get hot, wouldn't crash or anything. after a while crashing started occurring for me but there wasn't any overheating.
IMO your best interest would be investing in a new router, mine stopped immediately after getting a new one.
good luck
edit: i may be completely wrong, just make sure to check around on google and other websites and research it pretty well before you go an invest in a new one