To give a slightly more comprehensive anser to your original question, if it is a loose chain, it could be several things:
Oil pump sprocket could be loose- Stop driving the car immediately unless you feel like doing an engie swap, drop the oil pan, and tighten the oil pump sprocket bolts and add some Locktite or wire to keep them from working off again.
Chain tensioner could be going- When facing the front of your coupe, there is a bolt that sticks off the front cover of the motor at an odd angle towards the left side, approximately at the same height level as the fan. This is the chain tensioner. It is essentially a spring and a piston applying pressure to the chain to keep the slack in the chain to a minimum. The spring could be worn out or the piston could be marked up. Either way, it is a very quick thing to replace.
Chain guides could be going- This would be probably the worst thing, in terms of labor. Inside the front timing cover, there are two plastic guide rails that keep the chain's depth-wise movement to a minimum. These, coupled with the tensioner, eliminate most of the chain noise. Unfortunately, the only way to change the guides is to remove the front timing cover, which is a lengthy and arduous task that generally requires impact tools. If you are not mechanically inclined, I'd leave this task to the pros.
Chain could be going- Although practically unheard of, the chain itself could be dying on you. The chains are usualyl good for several hundered thousand miles, so a replacement chain is a very uncommon thing. If you are not mechanically inclined, this is another task I would leave to the pros, as it requires the same procedure as the guides.
lastly,
Cam sprocket could be loose- The chain connects to the camshaft via a large gear behind the upper timing cover. The gear has 4 small bolts that can work their way loose over time. As long as you leave the chain on (so the timing doesn't get messed up) this is a DIY job for those new to wrenching. All it should take is the removal of the distributor, then the upper timing cover, tightening the bolts, replacement of the timing cover, and re-installing the distributor. You might even be able to just remove the cover without removing the distributor from the cover, but I am not sure of that.
That covers pretty much all the elements in the engine that are connected to the chain system, so it has to be ones of those things if it is indeed the chain, or something associated with it.
