My mother inlaw just purchased a 99 caddy deville with 85k miles on it.It has the north,star engine in it and after driving it approximately90 miles staight its runs hot and starts steaming.The on board comp. then tells them to shut off the engine.This happened once before when they were driving to the mountains after stopping and at a mechanic shop they were on their way with no problems untill tonight when they were driving down from their home,After 90 miles the car did the same thing at about the same place on the interstate.anybody Know whats happening here?shes dead in the water right now and my inlaws are here at my house untill it gets fixed.HELP PLEASE!!!!!!!!

Dear Redbird,

The problem with the northstar engine, their are so many different reasons this car could be overheating
1) With 86,000 miles it could need a rediator flush due to the radiator being clogged
2) Possiblly the clutch fans aren't kicking in the cool the engine to the right tempature
3) Waterpump
4) Thermostat
5) Head gasket
As you'll notice I only scratched the surface your best bet would be to take it to a Cadillac dealer for diagnosis it will probably more expensive but they'll pin point the problem and fix it the first time I hope this helps a little