Oldsmobile/Buick: What is wrong with my Coolant system?, oldsmobile cutlass supreme, oldsmobile cutlass

Question
I have a 1989 Oldsmobile Cutlass Supreme.  It has 385,000 miles on it.  It is in fair condition with a good engine in it which is the Original.  The other day I poured anti-freeze in it and the next day it all leaked out into the garage.  Is the problem a worn our hose or the radiator.  And how much will it cost to be repaired?  A rough estimate? It has never been in any accidents and the tranny slips when the car is floored.  This is the Oldsmobile that had a Cradle bolt recall.
But I never had the time to bring it in yet.

Thanks,
JaY

Answer
Well Jay,
With 385,000 miles, you've been doing some serious driving! There are a few areas you should check before diagnosing a bad radiator. Though with it's age, most likely is the culprit. First you'll need to let the car sit over night to perform the initial check of the transmission lines going to the radiator, there are two. You should see obvious signs of leakage around where the line screws in. If that checks out ok, the upper and lower hoses come next. To do this the car needs to run a while. Pull off the radiator cap and watch for the flow of water in the radiator to stop. Put the cap back on. Now that the thermostat is closed, you can squeeze both the upper and lower radiator hoses. If there is a leak you'll see it. Radiators that have slow leaks are hard to locate. The reason is the water evaporates on the hot surface before you can see it, and turns to steam. The only way to be for sure is have it pressure tested at a radiator shop who has the tools to do it correctly. Having a radiator re-cored is less expensive than a new one. Though given the age of it, I'd go for a new one. Reason being that stress areas like the hose outlets are sometimes bypassed by shops and the metal may already be fatigued. A factory repalcement is the way to go. Don't let a sales guy talk you into some high capacity multi flue aluminum $300.00 piece which would do absolutely nothing for your car. These are for high performance applications. A repalcement radiator should run around $125.00-$185.00. You can install yourself. Just be sure you handle the radiator gently, they're easily damaged. Hope this helps! Ray