previous maintenance -
not just oil changes - but ALL fluids should have been replaced at least TWICE by 145K miles -
spark plugs should have been replaced around 100K miles -
belts and hoses should have been replaced -
a good indicator of previous maintenance is actually the current tires -
if they are Michelin - Cooper - or other high quality - fairly expensive tires -
chances are pretty good that PROPER maintenance was done - at least MOST of it -
on the other hand - if they are the super el-cheapo - house-brand tires -
the previous owners PROBABLY cheaped-out on other things too -
PROPERLY MAINTAINED -
the Northstar motor CAN run for several hundred thousand miles - without an issue -
keep in mind that you are looking at an 18 year old car with almost 150,000 miles -
depending on the specific model of the Eldo -
SOME suspension parts - struts and shocks - can get very - VERY - expensive -
IF you can even find them -
Do you have another car to drive? If you're planning on driving the Eldorado as your main source transportation I would think twice. My 02 ETC has less than half of that milage and at this point it's a toy and a garage queen. If you're buying it at a low price wanting to restore it and use it for a Sunday drive that's one thing. But if you're depending on it daily, look for another car. Don't get me wrong, they are beautiful cars and a joy to drive. But like many have said here cheap Cadillacs are expensive to drive. If you REALLY want this vintage of Eldorado my advice to you is read up on these cars right here on this site. There is a ton of information. That and look for one with less miles. Like byrdman said your driving and maintaining a $50,000 dollar car even if it cost you peanuts.
I find that the more often I drive my 2001 ETC that the car performs better each time I take it out of the garage.. I realize we are dealing with 18-year old parts, and they will eventually need replacing, as they would need the same in any car that old, but I watch it closely and keep a reserve in my savings just for this. I really love that car.
I would like to add that it is not my daily driver because it lacks the really cool electronic safety features my 2019 car has. Although fun to drive, it requires way more attention to detail when on the road, and in parking lots. So, I take it to car shows and club tours, but let it rest the rest of time.
"Electronic safety features" ??? I learned to drive in 1952 or so - don't really need or want any unnecessary bells and whistles. Attention to detail on the road is what lessens the chance of accidents (and tickets) and is what makes driving a performance car FUN - and I don't own a smart phone, so my attention is not constantly diverted.
I am guilty of parking the STS away from the crowd when in parking lots. And I don't need any sort of rear warning or camera systems.
None of the current "Car, take me to your feeder!" for me.