1999 Cadillac Seville STS from North America - Comments

I just bought a 99 Cadillac Seville with 105,000 miles and had a tune up & oil change done. Everything works fine except that my engine seems to burn too much oil. I always have this heavy oil burning smell coming out of the engine when I drive and worse when I park the car.

Any idea why? Thanks.

For the person on the this thread with the overheating 1999 STS, I too am having the same problem. I purchased a 1999 Seville STS last week. The temp gauge runs hot whenever I push the engine (usually on the highway) At first I was told (by the used car dealer) it was a coolant cap defect causing pressure buildup in the system. That was bologna. I had the cap replaced and still the same thing. I had the water pump and the thermostat replaced. Still overheating. I read on another forum that it could be that the second cooling fan was not operating. My mechanic said this as well. However, he could only find the relay for one cooling fan. Maybe that's the issue.

I purchase a 1999 (STS) with 70,000 miles a few weeks ago. The cruise control becomes inoperative at speeds over 65 mph. Receives a code 503 vehicle speed sensor intermittent. When this happens we get a service engine soon light and cruise will not reset. I have taken to two dealers. The first re-flashed the PCM and this did not help. The second dealer found a service bulletin Number 99-07-30-015 which call for replacement of all parts and case extension in final drive assembly. Bulletin states that they may have a mis-machined final drive internal gear outside diameter and a internal gear retaining ring that is incorrect. GM should step up to the plate and repair regardless of mileage.

GM has not issued a recall that we can find. Putting incorrect parts in a $50000.00 vehicle really gives you confidence in what you purchased.

We have had to replace water pump, front motor mount, all electrical in transmission.

Engine is loosing oil around pan gasket. I am told that this is a common problem for this model. Cost $500.00 to replace gasket. We had a 1993 (STS) and drove 175,000 miles and never dripped oil non garage floor.

Would I buy another Cadillac? Very good question. Don't want to buy a Japanese, but doesn't look like US mfg. really care about quality control.

In reference to the overheating and the smell of burning oil.

There are 3 relays that control the fans. One for each fan, and then one relay that controls hi/lo speed. More than likely, the one which controls the speeds is out. I don't have the number right in front of me, but it will say Fan S/P on it or on the diagram under the fuse box cover.

As far as the oil goes. You probably have a drip leak and the oil pan needs to be replaced. The reason you are smelling it burning and it may not be dripping to the ground is because the exhaust runs right against the pan and there is a brace under it that traps the oil and causes it to burn off. I ran into this problem myself on my 99 STS. From what I understand, it is very common. I bought the gasket for $12 from Autozone and put it on myself. Don't let some mechanic tell you it is a major ordeal because it is not. You will need to use a 3/8 ratchet and extension if you do it yourself.

I had A 1997 STS 179000 miles good car except for the fact that it wouldn't pass emition it leacked and burnt oil all over every spot on that engine it ran hot when parked not super hot, but hot then I got a 98 STS waterpump when out so replaced it ran great untill the head gasket blew SO I SOLVED MY PROBLEM I WENT AND I BOUGHT A 750IL and not a single no burning or leacking oil no heating up just pure V12 quality machine.

I have a94 Seville with a jammed glove box, is there an alternate way to open gas cap cover?

I have a 1999 Cadillac STS. It is hard starting, and also it will stall while driving. It seems like it is a electrical problem. Please help.

I just recently purchased a 2000 STS with 53k miles on it. The car runs well and I have not had any issues with it to date. I just notice the other night that the cruise control doesn't work. I reviewed the service manual and saw that the previous owner had it serviced at 7500 miles. has anyone had this problem and is this a simple or difficult fix? Please advise.

Wow. A LOT of interesting reading in these posts. I am a Deville owner, not a Seville owner, but I've found the true difference between a Deville and Seville is the shell around the engine and transmission. Everything inside is identical. I bought a 2000 DTS in, I think, 03. It had 114,000 miles on it. The driver's heated seat did not work and still does not. Since I live in Iowa, I'm not that concerned about it... especially since it's bout $1000 to have that fixed. Since I have owned it, I have spent a lot of money at the shop. I love the car to death and would hate to get rid of it, but in 1-2 years it's going and will be replaced with a Toyota or Honda that's rated for about 300,000 miles with few major issues.

My first fiasco was partly my own doing, but also I wonder if a shop somewhere had a hand in it. I could always hear a knocking sound, but didn't mind it as well as I should have. Finally one day I hear a POP from the engine and the Service Engine light is blinking! I limp it to the Caddy dealership to find out that one of the plugs blew right out of the head. After almost $700 in work, it now has a helicoil and a 100,000 mile Bosch Platinum.

Hey...ever gotten home from a long day of work, pulled into your driveway, run your windshield wipers and cleaned your windshield off and the wipers and pump WON'T QUIT??? Real unnerving. Ended up being a failed wiper motor control board. Luckily, I was able to pick up a wiper assembly from the junkyard, but the dealership still charged me $100 to replace it. Oh happy day... more of my income to the dealership.

I also got the "Gas Cap" message. The dealership said it was the (not exact name) fuel sensor that sits on top of the gas tank that had failed. They first thought it was the gas cap, replaced that at $20 and thought they had it fixed...nope. The the $100 sensor and $100 labor, which fixed the issue and I made them credit me the gas cap based on their mis-diagnosis. I spoke to a mechanic friend and he said that is common and was MY fault. He explained that when you fill your tank and the pump handle kicks off...STOP. I'm of the old days where you keep pumping to "top off" your tank. He said the spill over of fuel ruins that sensor. SInce then I've had NO problems as I stop when the pump stops.

As far as oil burning. Yes. I do a change, reset the %, and I get a low oil indicator at about 75% life, so have to add a quart. I get it again at 50%, so I take that opportunity to do an oil change. I've been told that the Northstar engine is notorious for burning oil. It's just a way of life for that car/model. If you don't want to put a quart in every 1000 - 1500 miles, buy a different car. Even for those guys that are "in the know" that claim it should not burn oil...I've talked too many historic Northstar owners and yes, the engine burns oil. So unless you can get Cadillac to rebuild the engine and guarantee it's oil consumption to near 0, just add the quart and enjoy the ride.

Next...struts. I suffer from the same problem as many posters. My struts are failing, and my DIC confirms it. I get a "SERVICE STABILITY SYSTEM" and "SERVICE STEERING SYSTEM", which are direct indicators of failing struts. I confirmed it with a reliable shop and priced out OEM replacements at $700 each. Holy s**t! At that price, I'll trade the car in and take the hit in the trade. After searching long and far, I found Arnott online. They sell fantastic OEM style replacements with sensor override plugs and they are VERY fairly priced. I matched them with some competitors, and Arnott just has better quality equipment. I will be replacing all struts and plates for $700 in parts for all 4, where OEM would have cost me about $2500 or more not including labor. Arnott is also privately owned and have very intelligent phone staff.

I also had to replace tires this year due to the winter season and my treadlife. I went with Goodyear's TripleTreads. I shopped around and found a local garage that offered a "cash card" incentive and an excellent price. They handle like a dream in the snow and I am confident that they will fulfill my expectations. I recommend them highly.

Power Steering. I noticed last year that my power steering got stiff and noisy. Checked it...empty. Wow. No warning there! I filled it immediately, but have to fill it every 6 months. My mechanic has told me to replace the hoses... but that was after writing a $1400 check for a front hub assembly, all new brakes, and replacement calipers in the rear for failed ones... along with a new water pump and thermostat. Ugh.

Now, the transmission is frightening me. For those that own Deville's and Seville's that you DON'T hear the transmission whine between 10 and 50 mph, you know what you can expect. The car did not do this when I bought it, but since then it has very slowly made a louder and louder whine. I have tried to search on this topic, and the more I read, the more I worry. Everything leads to a failing transmission, so next spring I will have it in to have the tranny run through. What I find odd and have read about the same is that my tran fluid indicator has said 100% since the day I bought it. Why? The oil indicator goes down, I assume based on viscosity. Why wouldn't the tran indicator go down even 1% for every 5,000 or 10,000 miles based on the same principle. I want to change the fluid and filter myself as I've done in the past on other cars, but the manual doesn't indicate any concern unless the DIC reports an issue. I'm learning not to trust the DIC.

I am NOT a mechanic nor did I attend school for that trade. I try to perform as many tasks as possible on my caddy since my local Cad dealer charges $150/hr. I also do not take my caddy to the dealer any longer. I have found a reputable shop with staff I trust. In the big picture, folks, stop going to the caddy dealer. Find a local shop with fair rates, $60~/hr, get to know them, explain your plights, and you will find that they will be reasonable. I've found by trial and error that the small shops, if reliable, act like real human beings. The dealerships "care" because they're stealing the shirts right off your back. If you could charge someone almost 2x what they could pay somewhere else, wouldn't you treat them like gold too??

Lastly, with 156,000 miles on my DTS, I am changing my philosophy. As of 2008, I am converting the engine over to full synthetic, buying and installing the most expensive oil filter AND air filter on the shelf, and replacing the air filter at every oil change. Why am I doing this? Am I insane? Nope. I'm being proactive. I'm tired of the shop bills, and I can't change water pumps, radiators, alternators, etc on this damned car, but I CAN change oil, filters, and plugs, so I'm going to buy the most expensive ones I can and change them (bar the plugs) often so I can feel justified that I have done everything within my own personal power to keep my car running in tip top shape.

Dan Abbott.

PS.

Within 1-2 years, my lovely Caddy will be sold and I will be buying a hybrid or full electric or some damned Camry or Insight. I drive 2 hours round trip every day to work, and even though I make great money, I don't need to see it go to the car twice to three times a year in major repairs that should have been worked out at the manufacturer level. (This coming from a man that went out EVERY night and kissed the steering wheel (car) "goodnight" for the first year he owned the car... so you understand how hard it will be to let it go...)

Best Wishes and Happy New Year.

I have 1999 Cadillac SLS and have starting problem. I changed the battery for $220 (including the labor). But still have the same problem. I bring back that car to Cadillac service center and they asked for $700 for replacing new starter on it. I am not glad at all and definitely I'll not recommended this car in future!!!

I have a 99 STS that shakes at about 55-60 mph. Does anyone know what the problem is?

I have all of the problems I've read on this site. I have a 99 SLS. I've replace the A/C compressor, starter, relay switch for the lights, 2 window motors, now the oil lights comes on stating low oil pressure. I smell oil after stopping and there's a leak.

Nice looking car, but to think this is one of America's best automobiles, wow! Is this what American products are like?

secondmillenn29@hotmail.com

I own a 1999 SLS with only 28,500 miles on it. What is involved in replacing the head gaskets? Does the motor have to be removed from underneath to do this job? Also would I want to replace the oil pan gasket at the same time.

Nice car, but I'm finding out that they have lots of problems. Any info will help. Thank you.