"I have owned four 97-99 Devilles they are great cars as long as it gets maintained. Before purchasing a northstar cadillac make sure to be alert for white smoke, or coolant smell since northstar engines are notorious for blown head gaskets. Alternators are also one of the components that fail the most on 1997-1999 devilles make sure battery volts are at around 13.2- 13.9 when car is running other way alternator is soon to fail. a great way to see if the car is in good shape is by checking the codes. to do that simply press on the A/C controlls the "off" and "warmer" buttons for aprox 5 secs, it will tell you all the codes, problems that are "history" are not to worry, but if you get codes that are "current" you might want to see what they mean before you make a purchase."
Pros: "Comfortable, good performance, good-handling."
Cons: "Parts and repairs are very exxpensive."
Likely to recommend this car? (1-10): 3
"Great car in concept. Not cheap to repair. Finding a bad sensor or relay can be a chore (there are three banks of them in three different spots in the car). Must use premium octane gas. For this year, Cadillac placed the starter and starter solenoid UNDER the intake manifold, making it a very expensive affair to replace. Otherwise roadworthy, comfortable, and reasonable (if not great) MPG. If you can find a used one and have the money for repairs, Cadillacs in this range can be found relatively cheaply. Performance is smooth and lively, and the ride is impeccable. Just be prepared for costly repairs."
Cons: "lower gas milege than new cars,21mph in town"
Likely to recommend this car? (1-10): 10
"I have had 3 cadilac's and I love them. I owned and 88 DeVille which was hit by a semi and totaled and I had to replace it and I got a 91 Eldorado and a tree fell on it 7 years later. But I loved the car. I bought My 98 DeVille in 2011 and I have enjoyed this car just as much as my other ones. They ride smooth. They are classic. My only complaint about my 98 DeVille is that this year of cars are so cheaply made in the interior. The corners of the headliners and vinyl seem to be coming apart and the decal on the outside of the car is bubbling. An expensive car like this was shouldn't have been using such cheap materials on it to be doing this. The wheels are peeling metal off of them. But other than that, the car is fantastic. It is everything a cadilac should be."
"We use these as private sedans. The head gasket problem can be avoided by simply following GM recommendations and putting "pellets" in the coolant (ask for them at your Caddi parts counter). The head gaskets don't completely blow, they warp because it's an all aluminum engine. You should run full throttle up an on-ramp a couple times a month to limit oil consumption (it keeps the rings loose). And finally, if you follow these simple rules, you'll get over 300,000 miles on it."