1999 Cadillac Seville STS 4.6 DOHC 32 valve from North America
Solid, safe, classy, and powerful; not for the novice however
Got this car a year or so back and it had been garage kept quite a bit. Upon buying the car I had to replace the following:
Spark plugs x8.
Ignition coil pack x1.
Two coolant hoses blew.
Power steering hose.
Air bag connector.
Oxygen sensor x1.
Coolant flush and unclog air purge line.
Burns 0.5qts of oil still.
This car has had a lot of issues, however most of those issues are wear and tear. When you get one of these used, it's all going to boil down to who had it before you and whether they took care of it or not. I caught an overheating issue before it got worse, and saved myself from the head bolt issue these motors are plagued with, which causes head gasket leak eventually. I encourage those who own this car to change the Dexcool coolant at proper intervals, and if the car ever starts to overheat past the middle mark on the temp sensor, pull over and figure out why or take it to an experienced mechanic; a lot of mechanics mistake a 5 minute coolant hose clog for a blown head gasket on these.
Now for the good; the motor makes a consistent 300+HP and lights the front tires all day long. The interior leather is strong and looks new after having all my kids in it, weekly spilling things and kicking things. The transmission is the strongest FWD transmission GM made during this time, and the fluid in mine is from the factory, and is still not burnt 130,000km later.
The car doesn't rust bad; undercoat it for complete protection; there are some spots that are vulnerable, but at least 90% of the car stays rust free even without undercoating.
Back to the coolant, these motors can in fact run for a while in piss poor shape due to the fact they have a limp mode and can run 50+ miles without any coolant. The longer you run it with something wrong, the less forgiving it will be, remember that.
Based on my experience with this Caddy and many others, for those who know cars and can maintain them properly, this isn't a bad vehicle and the work and parts are cheap doing it yourself. For those that want something easier to own, stick with an older 350 LT1 Cadillac or older 4.9L.
Would you buy another car from this manufacturer? Yes
Review Date: 16th January, 2021
17th Jan 2021, 04:11
Sounds like you get the both the Northstar & Dexcool issues :)
17th Jan 2021, 18:19
Never really seen Dex-Cool affect a Northstar engine where the coolant turns into mud. Mostly iron block engines such as the 3800, 3100/3400 V6's 305 and 350 V8's had the corrosion issues. It seems now it doesn't occur on modern day GM engines.