Timing belt replacement? 2004 Civic LX
 

I have what I can only describe as a "Cement Mixer" sound coming from the "front" (right side as you look at it) of the engine. In the area under the plastic timing belt cover.

The engine seems to run ok, not like it is skipping or anything. Another thing I noticed, my heat doesn't work. Could this be the water pump?

98K miles.

Any guesses appreciated. Probably going to take it to a mechanic, but want to have a decent idea of what is going on prior.

could be the water pump but its impossible to diagnose things over the internet but your due for a new timing belt and water pump. if your belt snaps or skips teeth say goodbye to your engine.

I vote its a bearing. Either the water pump or idler/tensioner pully most likely.

Even the balancer is suspect.