Saturn Repair: 1995 SC1 Engine Noise, poor quality fuel, oil starvation

Question
I have a '95 SC1 with 180,000km on it.  
I get the occasional tick from the engine in the first few minutes of warming up, which I presume is cold lifter tick, as it goes away once warm.
When I'm out on the road and hit the gas I get a loud ticking/rattling sound.  When my foot is off the gas I don't hear the sound at all.  If I'm cruising on the highway with my foot on the gas, the sound remains constant, but seems nowhere near as loud as when I am accelerating in stop and go traffic in the city (could seem quieter on the highway due to wind noise?)
I can't figure out whether it is upper engine related or exhaust related, and would like to have at least some idea before I take it in to a shop.
Thanks.

Answer
Jeff,
 I would have to say it's probably your timing chain.  As you accelerate, your engine's timing chain tightens up on one side and slack occurs on the other.  If you have never had the timing chain replaced on your engine, it's probably time.  As your timing chain stretches, the slack side just gains more and more room to slap against the chain guides.  
 The only other possibilities that I could think of are:
1.  Low on oil, causing oil starvation in the lifters.
2.  Poor quality fuel, causing detonation.  

With the amount of km's on your vehicle, I would go with the first idea though.  Once those 1.9L timing chains start going out, they tend to go fast.  I would probably get it looked at.  One easy way for you to tell if your chain is bad is this:

Remove the camshaft cover and feel both sides of the chain, on either side of the camshaft sproket.  The side closest to the firewall should be tight, and the side closest to the radiator will be the looser of the two.  That will give you a good indication of your timing chain's health.  Hope this helps, let me know how it comes out.  

Chris