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Video | I Bought the Most Unreliable Cadillac Ever Made: The 1993 Cadillac Seville STS Northstar

I just left Orlando, Florida, after a visit to some of my wife’s relatives– and wasting six hours of my life at Disney World to fly in the Millennium Falcon. Of course, I can’t go on vacation without buying a car — and though what I bought doesn’t look like much, it has it where it counts.

Well, kind of.

My latest travel memento is proverbial little old lady’s 1993 Cadillac Seville STS, and while the chances of this Northstar V8-powered sedan surviving my trip aren’t good, it’s nonetheless an interesting piece of Cadillac history.

Let’s go back to the late ’80s and early ’90s, when this generation of Seville was created. Cadillac was losing ground to its German and Japanese luxury competitors, but it was still in a very strong sales lead. In 1993, Cadillac sold more 200,000 vehicles in the United States — which, at the time, was more than Lexus and Mercedes-Benz combined. Now, Cadillac sells less than half the cars that Mercedes and Lexus sell individually. If you look at the whole picture, Cadillac’s market share began its long decline with its Northstar generation of cars. It was supposed to be the brand’s great evolutionary leap forward, and it could have been a massive success — if it weren’t for one fatal flaw.

The premise of making a Cadillac more European might seem like a recent concept, but General Motors hatched the idea more than 30 years ago. It hired Italian design house Pininfarina to design and build the body of the 1987-1993 Allante — Cadillac’s first convertible in more than a decade — which birthed a generation of sleeker, more modern Cadillacs. The midsize Seville was the first sedan to follow this design language, finally breaking from a look that had not changed much from the early 1970s. The move was praised, but Cadillac needed more than a makeover to catch up to the Europeans, so the Seville was also the first sedan to feature the Northstar V8 engine.

Marketed as the Northstar system, the Cadillac platform boasted standard traction control, active suspension and more refined handling properties. Of course, it’s the engine that’s best remembered, as the then-brand-new 4.6-liter V8 was a massive evolutionary step from the old pushrod 4.9-liter it replaced. With an aluminum block, higher compression and variable valve timing, the Northstar boasted 295 horsepower — about 100 more than the previous Cadillac V8. The advancements in engineering were almost German in their complexity, with such features as a water-cooled alternator and a water pump mounted to the back of the engine that used a small belt to spin the camshaft-powered impeller. The engine was also designed with the ability to run 100 miles without coolant, as it could alternate which cylinders fired, allowing the rest to be cooled by air to prevent overheating.

Of course, with European complexity comes a European level of problems. While the location of the water pump made it easy to change, almost everything else packed into the tight engine bay wasn’t. Fixing a leaky oil pan meant unbolting the engine from the car — if you’ve given a Northstar Seville a tune-up or replaced valve cover gasket on this transversely mounted engine, you probably never want to do it again. And it wasn’t just the high cost of repairs that Northstar owners complained about — there was a bigger, more fatal engineering flaw deep inside the engine that could mechanically total the car at any moment.

All manufacturers make mistakes, and some are more famous than others. Porsche has its IMS bearing era. BMW’s committed myriad engineering snafus. But these defects usually only affect a small percentage of cars, or the problems only persist for a few years before they’re corrected. But if you ask me, there’s not a mistake more enduring or more devastating than the head gasket problems on the Northstar V8. The head bolt was designed poorly, and the thread could strip the aluminum block and break the fragile seal on the head gasket. Once the seal goes, coolant gets into the combustion chamber, exhaust gasses escape into the cooling system — basically all hell breaks loose. Fixing the problem usually runs between $3,000 and $6,000 — often way more than the entire car is worth.

The head gasket issues are most prominent in the Northstar’s earlier years, from the first models off the assembly line in 1993 all the way through the 1999 models. Sevilles built after 2000 were fitted with an improved set of bolts, but failures were still widely reported until 2005, when the bolts were further improved. Not long after, the Northstar series of engine was phased out. The power plant is best remembered for this horrible defect, and little else.

Cadillac has struggled with its brand image in recent decades, and I think these poorly designed bolts deserve much of the blame. Buying used is the only way that many younger buyers with limited budgets can afford a luxury car. Cadillac had bet an entire generation of cars on an engine almost guaranteed to fail, and owners stuck with a blown head gasket loudly voiced their displeasure. Dead cars flooded the market, which tanked values even further.

It’s rare to see a Northstar-powered Cadillac from the ’90s still up and running, so when a viewer offered me his grandmother’s 1993 Seville STS, with only 66,000 miles, I was very surprised. It has to be one of the nicest surviving examples from the first Northstar year, and while it probably wasn’t the best choice for a 10-day vacation that went all over Florida, I bought it anyway.

So far, it’s been very well-behaved and extremely comfortable. A flood of childhood memories has come back to me — a Seville from this generation of Cadillacs was the last car my grandfather owned before he died in 2000. After he died, the car passed down to my uncle — and the head gasket blew not long after that.

Hopefully, my Northstar won’t follow suit before this trip is over. Find a Cadillac STS for sale

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  1. I am unaware of any car with as much or more engineering malice packed into it with an extremely clear goal to make it hard to service. They are perpetually irritating and expensive to keep running. These cars are a shining example of my visceral hatred for general motors.

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