My truck cabin noise continues to increase. The source is the engine because it is now obviously present when the truck is parked. So several source: water pump bearing, alternater bearing, loose valve adjustment, timing chain. I removed the fan belt, the noise remains so valves or timing chain.
So whichever it is, some work involved. If it's the timing chain, then repair best be NOW? If that goes out, would that ruin an engine? Valves is mostly inefficient explosions and then possibly burned valves eventually? .