Cadillac Seville STS Problems

Coolant Leaks From Water Pump and Radiator on Cadillac Seville STS

Problem Description and Possible Solution

The water pump and/or the plastic side tanks on the radiator may leak causing a loss of coolant. The engine may overheat due to coolant loss. Continued coolant loss after external leaks have been repaired could indicate a blown head gasket.

(54 people reported this problem)

Cadillac Seville STS Vehicles With This Problem

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Average mileage: 127,987 (12,000–240,000)
11 model years affected: 1993, 1994, 1995, 1996, more1997, 1998, 1999, 2000, 2001, 2002, 2003
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Viewing 1-20 of 21 comments
Coolant all over engine on passenger side. Front of engine is dry (where the belts are). I can't really see where the coolant originates from, as there is to much in the way (obstructed view). Not really sure how to track down what to repair/replace.
I have 99 sts cadillac. Haven't had too many problems. had everything check out about a year ago when i first our cased the car. Just recently i pulled my car out to find some leakage on the ground. Shortly after i noticed that my car started to over heat. I put in antifreeze and it helped for a few hours and now its back to over heating.
I am leaking coolant out of a small line off the radiator on the passenger side of engine. It is a rubber hose but then connects into a metal line. I dont know what this line is or where it goes but if someone could help that would be great.
After replacing the belt, the resorvoir started leaking the coolant. After a short drive, drops all the coolant like it has a hole.
First we noticed excessive oil consumption, then the radiator exploded then it started to over heat after radiator repair ,then loss of coolant, checked and found that head gasket was blown.


Not fixed yet need to know if recalled please help
bought the car assumimg it had a computer problem and come to fine that the car has a few problems dash was displaying low coolant, car overheating and drove the car for a week and now the mechanic is saying that the engine seals were blown and are banging out my warranty to rebuild my engine. do you think i'll have more trouble than i bargained for cause im feeling dooped.
Check coolant level message began coming on about 2 years ago. Told not to worry, two weeks later the radiator cracked and lost all coolant. Had car towed to garage. Parts replaced. 2015, message began coming on again. Had all remaining parts of system replaced, hoses, coolant tank, etc. 6 weeks later, message came back. It comes on, turns off after about ½ mile. Several days later, message comes on and stays on until engine is turned off. After that, it comes on and goes back on each time car is started stays on throughout the drive.
Now I'm told it may be the head gaskets. But there are no indications that the head gaskets are involved. Car does not overheat, no coolant is leaking out, no evidence of coolant on passenger side under hood or on ground. There's no mixing of coolant and oil when checking oil level with dipstick, no white exhaust from tailpipe. What could it be?
Car is 1997 Eldorado.
Coolant level low alarm - leak at top hose. Replace hose in parking lot, but not the problem. Radiator itself had crack in the plastic side tank. Partially unscrewed radiator cap to relieve pressure, filled with water and drove 90 miles home without stops. Replaced radiator. Alarm saved the motor
Bought the car new and have had minimal problems. Still has the original water pump. I've had two coolant leaks. Was fortunate to have both of them at home. Both were identical problems. The upper coolant hose clamp is a "squeeze" type metal clamp (a special tool makes it easy to remove but you can use channel locks). It rusted at the bottom, broke and thus under coolant pressure, we had a leak. A simple installation of a stainless steel screw clamp was the fix (replaced lost coolant). Several years later, same identical problem at the other end of those connection. Replaced broken steel clamp with screw clamp. Problem solved. This spring I am replacing all the rubber hoses (including heaters) and these metal clamps with stainless screw clamps. If you bring this into the garage for a repair only and honest, reputable dealer would change out the clamp (Labor and clamp probably less than 25 bucks). The skies the limit otherwise. I trust the dealers even less!
Year ago replaced my water pump. Only went back and forth to work for the year (50 miles a day), but did one small trip (400 miles total)where I experience car message Check coolant level and than overheating, refilled reservior and went on my way. Now about to go on second long trip when experience the same issue (check coolant level car overheating, drove 134 miles and back same miles with coolant top off. Took into shop and was told water pump is leaking and the radiator was shooting out coolant at the top on the passenger side of the radiator. Shop (non cadillac shop,Goodyear)says they'll replace the water pump again (part will be free, $200 labor) and they will replace the radiator ($250 for the radiator and $300 labor).