How do you tell if you have a bad water pump on your car??? Is it difficult to replace?? My heater core is also taking a dump on me. How hard is that going to be to replace??
I have a 1988 LO3 TA..

 

Chevy water pumps have a weep hole in the bottom of them. When they go bad, they'll leak coolant out of it.

Heater cores are a pain. They're way up inside the dash.

 

The heater core is easy, but very time consuming. It's been a couple years since I replaced one, but you will need to remove the entire dash. I started out by draining the cooling system, then I had to cut the 2 hoses that attach to the core. ( you probrably will too they are cheap to replace) I then went inside and removed the center console and radio pod to make things easier and to have more room. Then the dash pad came off, and I started unbolting everything thing underneath, I believe there are 4 big (10mm) bolts that are at the upper and lower corners of the dash assembly all the rest of the bolts should be 7mm. The 2 bolts that hold the steering column (1/2") will have to be removed also, and you'll have to drop the column. You do not have to remove any of the guages. Once everything was unbolted I pulled the whole assembly off. The heater core is on the passenger side inside a black plastic box, take off the cover, pull out the core, you'll have to wiggle it around.(keeping in mind not spill coolant on your rug) Then replace the core. (about 40 bucks at the auto part store) Then replace everything, keeping in mind to insure the guages are connected before bolting it up. The whole job took about 7 hours by myself (an hour of which was being stubborn and trying to pull off and save the 2 hoses, just cut those damn things!) Your probrably better off doing it with 2 people. Repair shops will charge about $500.00 to do the job. To the best of my memory (I had about 8 or 9 beers in me by the time I finished) this is how I did it.