Hello all,
I have a 1997 Pontiac Grand AM GT, 3.1 V6, about 120,000 miles.

For about 2-3 years I heard a ticking when I first started the engine but with no other problems. It would warm up and then the sound would go away. The engine still ran great.

Recently, for 2-3 months the ticking got worse and I started to loose just a bit of power every once in a while. That slowly got worse too. Now the ticking is much worse and constant. Now I can only accelerate slowly and I have much less power than I should.

Going up a hill is tough. I have to find just the right position on the throttle and even then it'* very slow and sluggish. She used to love hills :(

Now the ticking has become or is accompanied with what sounds like air escaping, as if a valve is not closing completely or a seal blew. I hear a pish, pish, pish.

It almost feels like I'm missing a cylinder or a rocker assembly is loose?

I haven't tried anything yet with the valves. I did just replace a heater core and just after that the water pump blew. I'm assuming this is an unassociated issue. I had an overheat recently.

The ticking may be associated with a leaking exhaust manifold. It would likely be right where the manifold meets the engine. My second guess would be a blown head gasket. Have you checked either of these things?

X2...A blow head gasket would be easily seen by white smoke in the exhaust, sweet exhaust smell and loss of coolant.

How'* the oil look? Milky, watered down, foamy?

With the recent over heat issue there could by any number of issues from a warped head(*), exhaust manifold leak, cracked block, intake manifold leak, etc. Let'* systematically start looking at things and eliminating them as a possibility.

Get a compression test. My thought is you had a lazy lifter and over time may have damages a push rod or rocker. A compression test would tell you if you have a burned valve. Pull the spark plugs and inspect them. Post up the pictures if you can. make note of which cylinder the plug came out of. Watch for black plugs.