Engine fouled spark plugs on 2 of the cylinders on a regular basis (about every 10,000 miles or so). In addition, there were a few minor oil leaks and lots of valve train clattering noise the entire time I owned it (the early 305 V8's were noted for having weak camshafts, not sure if that was the cause of the noise). The noise never seemed to get any worse, so I left it alone.
Starter went bad.
Needed a new water pump.
The differential leaked a little bit.
Original carburetor made engine idle way too fast when cold (1500-2000 RPM) and way too slow when at operating temperature (barely running). Couldn't be adjusted, replaced with a used carb from the junkyard.
Transmission was starting to fail around 125,000 miles, still went approximately 13,000 miles beyond that (strong transmission!).
Needed a little exhaust work.
Needed new front shocks.
Needed new idler arm in the front end.
Needed new front brake pads (normal maintenance) and new rotors (my fault for letting worn down pads go too long).
Speedometer and odometer both quit working at 128,000 miles. I'm guessing the car had 135,000-140,000 miles (I'll average and say 138,000) when I sold it. This was because the speedometer drive unit in the transmission wore out.
High beam headlight switch broke before I bought it, never did get it fixed.
There was a mysterious water leak that I could never find. Sometimes water pooled in the rear passenger foot well. There was no rust through in the floor. It never smelled musty or moldy, though!
This was a great car overall. Sure, there were some issues, but it never left me stranded and I really didn't have to put a whole lot of money into it to keep it going because parts were inexpensive. The issues I had were mostly "old car" issues which is to be expected. It suffered some neglect before I got it and I drove it rather hard, yet it kept right on going!
It was a Caprice Classic Landau coupe, of which only 21,824 were made for 1979. Not rare, but not too common, either. It was light green and had a white "elk grain" vinyl top that covered the forward 3/4 of the roof (one of the distinguishing features of the Landau coupe). I loved that car and I really miss it. I bought it in December 1992 for $900 and put approximately 58,000 more miles on it by September 1995, when I parked it and bought a different car. By that time, it was pretty much "used up." It sat until May 1997, when I sold it for parts.
There were a few things I didn't like: It was underpowered. The 2 barrel 305 V8 was only rated at 130 horsepower, not nearly enough for a car this size. The 350 V8 would have been a better choice. The workmanship wasn't quite what it should have been; some of the panels didn't line up well and the dash had a few flimsy plastic bits...I've seen much worse, though, and in fairness, many cars of the late '70's had quality issues.
There were a lot more things about the car that I did like very much. The ride was nice, the car was very comfortable, roomy and pleasant to drive. It was great for road trips! The gas mileage was around 16-20 miles per gallon overall, not bad for a full size car with a tired engine. It handled very well for a rear wheel drive full size car-it was extremely well balanced. It was even good in the snow. What I liked best of all though, was the styling. Chevy did a wonderful job making this car look great inside and out. It was well proportioned, not a line out of place anywhere. I loved the rear window with its sharply creased corners wrapping around to the side of the car; it gave the car a sporty yet formal look that was just right. They only made that design from 1977-79, and only the 2 door coupes had it.
There are some Chevy's that enthusiasts consider "classics": the 1955-57 models for sure, and arguably the 1965-66 full size models as well. These are cars where they got (almost) everything right. In my opinion, these 1977-79 full size Chevy's (Impala/Caprice) fall into that category as well. Not perfect, but close. I really want another one. I had a '73 Caprice prior to this one (my first car, which you can also read about on this site) and while I liked that one, between these 2 cars the '79 was my favorite.