1995 pontiac grand am quad 4 motor are they relaible? was it a good gm car?

 It's a nifty and compact powerplant, but it's not without its faults. One is with the headgasket. It usually fails on engines with over 100K mi on them. Usually you'll lose power in one or two cylinders. A check of compression and the cooling system in in order to be sure. Another problem to look for is cracking on the actual cylinder head between the spark plug hole and valves. One more thing to watch for is failure of one or both of the coil packs, as they're subject to heat and vibration due to their tidy placement in the IDI assembly. Early models had injector problems that was solved later on. 

Most people thought highly of the Quad-4 engines. Might Google that engine and see what reviews there are for this make, model, engine.

The water pump is timing chain driven and very pricey to replace, make sure there's no coolant in the oil crank case and pressure test the cooling system before you buy.

The quad 4 engine was introduced back when there was a lot of speculation about V8's being obsolete, gas hogs, etc., and car makers were battling weight and big horsepower in order to meet the federal corporate fuel economy standards. They thought the quad 4 engine was the future. Well, big horsepower V8's are alive and well, and 4 bangers aren't the big money maker GM hoped they'd be. Instead, car makers are investing in electric and hybrids in order to meet the economy standards

A 2.4 OHC engine? Yeah they're good engines, but difficult to work on. The came in less than 20-25% of all GM cars and can be tuned really well.

If you are going to consider it:

Take it to a mechanic

Make sure maintenance was done at prescribed.

There is no transmission dipstick to check it

Make sure it has pink anti freeze. I've replaced several ppls GM water pumps and it's a huge job on an OHC 2.4.

I'm a GM guy. But you'd be better off buying Asain.