1997 Cadillac Seville STS 4.6L V8 from North America
A beautiful, powerful car, sadly made by GM
The list of what did not go wrong is shorter. Here are the main issues. There were many other things that went wrong with the car that are not listed. I just don't have that much time.
Multiple engine oil seal leaks fixed by the dealer under warranty at 45,000 miles. Had to remove the engine from the car on its subframe to fix everything.
Sunroof track replaced by the dealer under warranty at 45,000 miles.
Both rear window motors failed at 55,000 miles. Replaced under warranty. How could they fail at that mileage? The rear windows hardly ever were used.
Radiator leaks. Replaced under warranty at 60,000 miles.
Water pump failure. Replaced at 75,000 miles at my cost. Water pump is run off of the cam.
Tail light fogging. Chronic problem with this car model. Drilled a small hole at the bottom of the housing. This allowed the vapor to not collect.
Engine failure due to massive head gasket leaks at 95,000 miles. Decided to not fix and just sell the car at a massive loss.
This car was both the nicest and worst car I have ever owned. The fact that a car costing $50,000 in 1997, that was the flagship vehicle of GM, was so bad, makes you understand how GM ended up in bankruptcy.
This car had everything in it except quality.
The car was well cared for by both the previous owner and myself. All maintenance done on time. This car is just badly designed and poorly assembled with substandard parts.
I purchased this car in late 2000 for $20,000. Imagine a $30,000 depreciation since 1997.
Had to sell it with a bad engine for $3000 in 2006.
The STS felt solid, was very fast, and very comfortable and quiet. If it had the least bit of quality built into it, it would have been a great car. As it was, it was a money pit of incredible depth.
When I bought the car, I purchased the extended GM warranty from the dealer (up to 70,000 miles). I should have known something was wrong when the dealer sales rep told me I was very smart to buy the extended warranty.
The Northstar engines have a bad head/block and gasket design that creates coolant leaks into the engine. This fact is widely known. I worked in the automotive industry, and the GM engineers even admitted there was an issue with the engine, but the company would not allow them to spend any money to correct the issues.
I only wish I knew that back in 2000 when I bought this STS for my wife. The Internet has changed all of this now. Lots of information available.
Do not under any circumstance buy one of these cars.
Would you buy another car from this manufacturer? No
Review Date: 19th February, 2013
Cadillac engines have had this problem since 1982 when the HT4100 came out. The main problem is the inferior gaskets GM has been using for the last 30 years. The HT series engines include the 4.1, 4.5, 4.9, which have cast iron heads and cast iron cylinders. The Northstar only has cast iron cylinders. When these engines reach operating temperature, the metals expand. When they cool down, the metals contract. The soft aluminum expands and contracts at a different rate than the iron - so the gasket in between these metals gets torn over time and blows out. Instead of GM using better gaskets - i.e. diesel grade gaskets, they just mandate the use of block seal to patch the leaks that will inevitably develop. It's a design flaw that GM has been very aware of for the last 30 years, but they refuse to do anything about it because the engine usually lasts through the warranty period.
This is the reason why the rear-drive Brougham in 1986 switched to the durable Olds 307. It was the best thing they could have done for the traditional buyer, who wanted a real Cadillac which lingered on for several years later.