They rattle pretty good when first started and continue to do becuase of the head design. What to look for? Blue smoke after the engine has warmed up. I had an 84. When we bought it, it consumed oil. Got to the tune of a quart every 40 miles. We put a new engine in it. Before the new engine it smoked really badly upon acceleration, and it was pretty black. The new engine ran much better with almost no smoke. I put many hard miles on it 200+miles a week for 4 years. This was high school years. My sister drove it 3 years the same trip and my brother drove it 3. 5 years too. It had about 6 head gaskets, 1 clutch, many rear struts, 2 sets of motor mounts, many sets of tires and many glow plugs. But is was almost always one of the few cars that made it to school on very cold days, and started and made it home on cold afternoons. The neighbor bought it for parts, my brother drove it to his house. His rabbit truck motor blew up. He put our motor in it. After he drove it a while, he asked my dad if we turned it up. Dad said "nope, it was fast enough that all my kids got speeding tickets in it!! :-laf
If your g/f won't let it warm up on cold days, it will blow head gaskets. They have aluminium heads and cast iron blocks. The lack of warm ups, and drag races from the school parking lots in the cold afternoons caused the head gasket failures in our car. Those little engines rattle pretty good, to some they all sound like they are knocking. I can't explain what it would sound like. You can find some that don't use oil. We never had to use the dipstick with the new engine, but we would get our buts kicked it we did not. That new engine NEVER needed oil added to it.
Its kinda funny. All the thousands of WOT clutch drops that I did to it, the 2nd and 3rd gear tire chirps the trans never gave any troubles, it never needed a CV joint or shaft, and the clutch failed because the rear main seal leaked oil on it.
I can remember one winter saturday night we were out playing CB tag. My buddy and I had just found the vehicle that was hiding, and we were going to "tag" them. I goose the "rabid diesel" as it was called, and was going to climb the curd to get them and there was a loud WHAM. I fully expected the oil pressure light to come on, but it never did. My buddy and I jumped out expecting to find oil pouring out from every where. BUT the oil pan wasn't hurt at all. I think it was almost bullit proof! In the snow it was a blast. It would go through the snow until it could push no more with the front bumper. Then you shoved it into reverse wound it up and dropped the clutch. She would throw up two rooster tails and back out of anywhere! It always had some aggressive snow tires for winter travel. Sorry for the long post, but my friends and I have endless list of stories about that car! Even with the never ending abuse it would still knock down 40-45 mpg.
Michael