26th May 2009, 15:12

I have a 99 SLS. Only problems have been the fuel pressure regulator for the fuel injection, at the same time a leaky water pump was found. Other that that it's a great car - especially on the interstate, it gets over 28 mpg @ 75 mph. Around town average 18-19. Better than my girlfriends Accord!

Just like a Corvette, parts and labor are pricey at a dealership, that's why it's called a Cadillac/Corvette Tax (LOL).

The SLS doesn't like to be driven hard, when I first got it I almost went off the road sideways a few times. An AMG Benz it ain't.

There is the oil consumption thing to deal with. At first I went nutz looking for drips and leaks, checking the exhaust tips for oily residue, etc. it is, apparently normal for the N-star, just part of the expense of driving a Caddy. I do keep an extra qt. or 2 of oil in the trunk, just to keep them handy. Overall an enjoyable car, but expensive to operate.

Ciao, ya'll, Mark.

8th Jun 2009, 15:47

Our 99 sts cadillac stalls out when driving, sometimes when stopping for a light, sometimes when coming off the expressway it stalls out. Now it is not starting - either from sitting overnight or after driving and then sitting for an hour or so.

Anyone having any problems like this?

We have taken it too many mechanics, changed battery & cables still doing it.

Would appreciate any help. Thanks.

9th Jun 2009, 19:06

I have a 99 STS with a ironic problem. When the key is on but not started everything works perfect, but when you start the car nothing electric works, my windows my locks and my music does not work; when I turn the car off and put the key back in the on position everything works perfect, I have no idea what it is, it just started happening one morning, if any one may have information please let me know ASAP, thank you.

23rd Jun 2009, 18:06


The 2000 STS has survived 137,000 miles, and now the rear air shocks don't pump up even with no weight. They show a very low ride height. Has anyone experienced a similar problem, and if so would you share the repair necessary to bring back the quality ride height necessary to prevent the bottoming out effect

Contact Mike Artis 317.605.1361 true STS enthusiast.

30th Jun 2009, 15:09

I have a 1999 Seville SLS. I have had it for about 2 & half years. I bought it with 58,000 miles and have put about 30,000 miles on it. Like some of the other comments, my Seville shuts down without any warning. Sometimes the shut down occurs at high speed and sometimes when I am just starting or stopping. It is also sometimes difficult to start. Has anyone found a solution to these issues?

1st Jul 2009, 10:25

My radiator just went after I was smelling anti freeze, so how hard is it for someone that has never touched a radiator before to change it?

9th Jul 2009, 19:47

Just sell the car as soon as you can, bad engine period.

10th Jul 2009, 00:39

Reading these stories about all the problems people seem to be having with the STS caddies is scaring the pants off me.

I bought a pearl white 99 STS about 3 years ago with 75,000 miles on it. I now have 121,000 and believe me or not, have had absolutely not one problem yet.

I have always run synthetic oil and change it at 7000 miles rain or shine. I'm 56 years old and always owned big block muscle cars all my life. Its the most comfy, smooth car I've ever owned, and I'm proud to have it in my driveway.

I'm writing this to let people know there must be some real good STSs out there, because I lucked out and got one. I'd sell it in a heartbeat if I had some of these problems I've read about (HOLY COW).

If you read other sites on BMW, PORSCHE, etc, you'll find the same bad things happen.

I hate to say it, but facts show, dollar for dollar you can't beat Toyota for true value, but driving a Toyota just isn't my thing. Good luck to all the other readers on this site.

13th Aug 2009, 14:26

I love driving my 99 STS.

5th Sep 2009, 19:31

My caddy started off great. I bought it with 56,000 miles on it. In two years the shocks went out, replaced the radiator, water pump, thermostat, and now it seems like I have to replace the head gasket. Pray for my car.

8th Sep 2009, 05:53

I bought my 1999 STS 5 years ago. It had 56,000 miles then, and 98,000 miles now.

I just replaced the original battery with the best I could get. The battery cost me $90.

The original battery lasted 9 1/2 years. Amazing.

Electrical problems were intermittent, including display going blank. I disconnected and cleaned every ground wire I could find, and haven't had an electrical anomaly in the three years since.

It uses a quart of oil every 1500-2000 miles. Big deal.

I use only synthetic oil and change it and the filter when the computer says to; about 7,000 miles.

I replaced the power steering pump because it started whining about 2 years ago. Easy work.

Immediately after purchase, I added a three ounce Oil Shot to the A/C system, and just did it again yesterday.

A good thing to do on every A/C system about every 5 years.

Love the STS.

5th Nov 2009, 15:55

I am looking for answers to the comments about the STS shutting down while driving. I have a 1999 with 35,000 on it (I bought it from an older couple). It doesn't seem to have any other problems. Thank you in advance for any information on this problem.

25th Nov 2009, 19:15

My 1999 Cadi STS is a living nightmare. Sell sell sell or trade. It's a bad marriage, a good ride, but a nagging mistress. She always heats up and is never satisfied. She wants a water pump, a thermostat radiator. All this and still not satisfied, and you guess darn right, still overheats.

13th Dec 2009, 22:23

I have a 99 STS 90000 on it, bought it 5 years ago with 54000. Was shutting off at anytime with no warning. Would start back up after a few minutes. This went on almost a year before it was found, at dealer. (almost drove me nuts) there is an *Ignition Switch* in back of the dash. (not key) switch. Repair at dealer was $428.00 in 2005. Part was $97.00. Has not done it again.

Waterpump replaced at 64500.

Now rear shocks raise up and won't reset. I can pop the air lines to let it down, and within 75-100 miles of driving, it is back up. Can anyone help me with this?

25th Dec 2009, 18:06

This is for the person who's car keep shutting off; mine did the same thing. The problem is the crank sensors, but that was for my car, it could be something different.

I also would love to know why my windshield wipers won't work. I tried all the fuses and that isn't the problem. Anyone got any ideas?

6th Jan 2010, 15:09

To everyone who is complaining about over heating issues and have already changed fans and therm, sorry to say but you need new head gasket. I just went thru that in my 99 SLS; tried everything, needed heads and now have no overheating.

Now I am having the same issue I see a lot of folks having; the car shuts off when it wants to and starts when it feels like it. I have checked everything! Battery, alternator, key, ignition, starter, fuel pump, all is good. I see someone posted "ignition switch". I'm trying that next!