2002 grand prix engine ticking?

I agree with spinner elephant rocket fart. If you're not into cars and pull a part, a 13 year old Pontiac is not the car for you. Find a reasonably maintained Honda or Toyota that suits you.

The ticking noise is probably the lifters because you said the noise went away after two minuets, this means the car probably sat for a while and the oil pressure was really low when you started it that's why it made the noise, when the oil pressure got to normal the noise would go away like you said. I have a 1998 Pontiac Grand Prix GT with the 3800 v6 with 170,000 on it, these engines are pretty much bulletproof with only 80,000 some miles on it it should last a long time expecaly if it wasn't exposed to road salt,but I do know that in the 2000's GM cut Pontiac's budget on the Grand Prixs so the quality might have gone down, but you see tons of grand prixs on the road so it will probably a good buy. Carfax will not help much besides to tell you if it was in an accident because they probably will not have a detailed service record.

The ticking is likely nothing to worry about. As suggested it would be good to find out if the intake gaskets have been done and to check for tell tale signs of leaking. If everything checks out and if the price is right I wouldn't shy away from it at all. GPs are great cars. They are typically good for about 200,000 miles if you look after them so this one is not even half used up. Of course it will require some maintenance from time to time, its a machine after all. There were bazillions of them made and they've got a good reputation.

It could also be a piston "smacking" because when it is not at running temp its pistons are smaller ( it sounds stupid but the heat makes them swell to fit just right ) but just let it run til the noise goes away and then you can drive

I had this problem after fixing the upper and lower intake gaskets and no I had no coolant in the oil yet after I fixed it and put it back together two of the lifters on the back head starting pecking very loud. I was so mad because the engine never pecked before it had 88K on the clock. I ran mystery oil and risolone through it for -1500 miles with no success. The weather hit 14 below here and I took the battery out of the car for 48 hours this completely reset the computer and guess what all you mechanics no more peck car runs like new horsepower restored. No I'm mot kidding I was ready to take the dm thing apart again and replace the rods and lifters but not now all power restored.

Would be interesting to know what it would have been showing for trouble codes. Just goes to show it’s always important to do proper trouble shooting before tearing into an engine and starting to replace things.