Advice on buying a 1996 Seville STS or SLS

[Farnellb]

I have admired these cars for years, and I can, at last, afford one.

Would someone please advise what to look for, and what to look out for?

Thank you for your help.

[KHE]

I would say the single most important thing to check is the head gaskets - test the coolant for combustion gasses before buying. If it fails, walk.

The next thing would be to run the codes - if P0741 shows up, that can mean an expensive torque converter repair.

[Cadillac Jim]

With any used car, get a CarFAX or equivalent to reveal title history as a fleet car, flood damage, serious accidents, etc. and, with a GM car, get the VIN and have a dealer look at the maintenance history. Don't make a firm offer without a mechanic's inspection. There are services offered specifically for used car buyers that run about $125 per car inspected. With a Cadillac up through 2005, you can run the OBD codes from the dashboard; with others, take them by an Autozone and get the OBD codes read for you. All of them, not just the PCM or emissions-related codes.

Nearly all cars out there these days have aluminum engines, or at least an aluminum head, block, or intake manifold that has coolant running through it. Have the coolant checked for acidity at any radiator shop. If the owner has let the coolant go too long, any car is in for some expensive repairs of one type or another. With the Northstar and most other engines with aluminum heads, head gasket leakage is an inevitable result of letting the coolant go too long, and acid coolant can get into the head bolt wells and corrode the threads and the head bolts start pulling.

Check the oil and transmission fluid. If they have a strange color or odor, find out why to your satisfaction or pass on the car.

Give the car the bounce test. Many Cadillacs have an electronic suspension, which means that struts and shocks are expensive. If you buy passive shocks and struts for such a car, you must bypass the car's computers and settle for a compromised ride and performance in terms of handling and braking, and possibly very high speed stability. Check and see if that has already been done, and, if so, consider that in the attractiveness of the car and the price you pay for it.

Check the tires and brake pads. Cadillacs come with high-performance tires, particularly the STS, ETC, or other model with a "T" as the middle initial. Buying cheap tires on such a car again compromises performance and safety over what the car was designed to provide. Again, if the car has worn or cheap tires on it, consider that in the price you pay.

Look at the water pump, which is on the front head on the driver's side, driven by a pulley on a camshaft. Make sure that the belt is good, that the idler/tensioner is in good shape, that the pump itself doesn't leak, and that it doesn't put out noises.