1995 Saturn SL1 Car pops

On the timing chain when they start making noise they should be replaced. If your belt is squealing you probably have a weak belt tensioner so I would check that out before it leave's you stranded. Now on your popping are you talking about the engine popping or are you talking about the transmission shifting hard?If your transmission is shifting hard then you have a transmission issue. Lets do this on the drivers side
bottom of the dash there's the obd1 connector where you would put a code reader on. Look at the top row of it far right side there's two pins side by side. Turn the key to the run postion don't start it and jump those two pins together and leave it that way. Watch the service engine soon light flash. You will see it flash once then two faster flash's. That's a code 12 that means the computer is good it will do this 3 times if it repeats the code 12 after the 3 times you don't have any codes. But watch the light for example if u see 3 quick flash's then 2 quick one's that would be a code 32 it would repeat 3 times then go to the next code when it gets back to code 12 then the code's are done. Let me know what you find and we will go from there.