Another thing you could do to see what the problem is would be to bring it to a car repair shop. Some places will plug the car into a computer for free to see whats causing the light to come on. However, the light has to be on to tell them anything.
I finally did take the car into a mechanic. He said that the idle was way off. He corrected it. The check engine light stopped coming on after that. (knock on wood) We replace the thermostat and the radiator cap. It is still overheating at times. We're going to replace the water pump. It also needs a new valve gasket and oil pan gasket.
Are Ford Crown Victoria 1989 good cars, cause I need to know before I buy this one?
Where is the power steering at on a Crown Victoria 1989, cause I need to know? Can someone please help me out?
In regards to the heating problem mentioned in the comment from 7th Mar 2005, 13:48, I've had my '90 Crown Vic since May of '94. It was my former company car and I bought it from my employer when it reached the mileage limit where the company put its cars out to pasture.
I was the second person the car was assigned to, and from the moment it was assigned to me, I noticed it had a run hot problem, especially with the air on and pulling a grade. It would never get out of the normal range, but would get to the temperature where the A/C compressor would kick out. I chased that problem across 30k miles, replacing water pumps, thermostats, a radiator and fan clutch before I finally found out what it was. I even installed the police/taxi air dam option (a Ford part) across the front of the super structure under the front bumper. It helped quite a bit, but didn't solve the problem.
What it turned out to be was the coolant mixture was too strong on the ethylene glycol mixture. Apparently, Ford had a problem with those era Crown Vics & Merc Gran Marquis if they didn't run a 50/50 mixture in the cooling system. In doing some research, apparently Ford issued a service bulletin to their dealers back when the cars were new outlining the problem on how to fix it. When I found that out, I took a hydrometer reading on the coolant in the radiator and it was almost straight coolant, installed by the last place that serviced the cooling system and not a Ford dealer.
I looked up the cooling system capacity, which is 14 quarts total, drained out the radiator, which took 1 gallon & one quart. That left 9 quarts left in the engine block and heater core, so I filled up the radiator with straight water, fired the engine up and let it run until the thermostat opened and mixed the water and remaining coolant and then took another hydrometer reading, which showed the protection level right where it should be both for hot and cold. So seeing this, I capped the radiator and drove the car under the same conditions and up the same grades where the problem had been happening and the problem was gone!
So you might look into that. It worked in my case.