95 960 Water Pump failure?

[davidbnc1135]

Hi everyone, I've gotten a lot of help for little problems from this forum as a lurker. Today I ran into a bit of a big-ish problem.

So, I was driving my 1995 Volvo 960 sedan on the highway today, revved up and passed someone and all of a sudden my coolant light came on (no overheating). Pulled over, popped hood, and my overflow tank was dry (it was at the max line when I left home 5 minutes ago), with coolant steam coming from what I though was the driver side near the steering column. As it wasn't overheating (according to the temp gauge) I turned the heat on max and limped home.

When I got home I parked and added coolant. I've had a radiator hose bust before, so I expected that as I added the antifreeze It'd come right out of a hose and I'd find it and replace it. Nope. Nothing. I added it and it just stayed in the tank. So, I turned it back on and added a little more, and let it idle for a little. Still nothing. No leaks under the hood on any hoses, no dripping under the car. So I thought, well this happened when I was at much higher rpms (passing someone, a little aggressively) so I revved it up a little (i'd say 3500 ish, could be wrong) and I check the under the hood and still no leaks, BUT i noticed my tank was a little lower so I look under the car and BAM. I found it. It was leaking from around the front center of the undercarriage.

So I found the general area of the leak, put it on jack stands, revved it up once more, turned it off and got under to look. It seemed to be leaking from up above the oil pan. Like right above it. I felt around for hoses and could find any. So, after much frustration I go inside and google coolant leak above oil pan. After reading from a bunch of different sites I came to the conclusion that it's the water pump, and I've got coolant leaking out of the weep hole and I need a new water pump. Made sense, the previous owner's records show they replaced it, so I ordered one and will go to the mechanic Wednesday morning.

NOW a friend of mine mentions that it might not be the pump, and actually the coolant temp sensor? I was almost certain I knew what it was, now I'm not. Did I just waste money on a new pump and scheduling an appointment with my (apparently super busy) mechanic? Should I have them check something else instead of giving them the pump and having them install it? I'm not rich, and the labor and part are already really cutting into money I had set aside for other things.

What do you think? Water pump or no?

Thank you so much in advance