I hope somebody has some idea on this one...

I have a 1992 Accord, only 140K on it. Just recently, the temp gauge started going up and down... like with no pattern at all. So, after flushing and filling the cooling system, and replacing the stat, it's still acting crazy.

The fans are cycling as they should, and it appears as though there is flow through the radiator.

My question is this: could the water pump be bad - intermittently? Like, could it be pumping sometimes, and then other times not be engaging fully? It doesn't seem like the flow I see in the radiator is moving as fast as it should be at 2500 RPMs. Also, when I come to a stop, and it starts to heat up, if I rev it up to 2500, it immediately goes back down to normal.

Any thoughts?

Oh and one more thing - how hard is it to get to the water pump if that's what it is? It didn't jump out at me when I looked for it this morning...