We have a 98 Windstar that has never run better (you read that correctly). We bring it in regularly for maintenance. A few days ago the engine light came on. I checked the engine oil and the transmission fluid and both are fine. A engine continues to run very well. What could be wrong? Should I bring it in or wait till my next scheduled check in the fall?
The “Check Engine” light is a sort of catchall, which indicates a trouble code was generated by the computer. This can be anything from a bad sensor to something considerably more serious. You need to find out exactly which trouble code(s) have been generated in order to begin to fix the problem. If everything seems to be running fine, it’s probably nothing imminently serious, but bringing it to a competent mechanic to find out what triggered the light is only prudent.
Many auto parts stores have a code reader they can plug into your car under the dash, for no charge. It will tell you what allegedly went wrong. Sometimes, it’s as small a thing as a fouled spark plug, a dirty filter, or even a loose fuel cap! That’s right, if you didn’t tighten your cap until it clicked, you’ll get a check-engine light. Anyway, these are things you can fix yourself.
You can ask the parts shop guy to cancel the code and see if it comes back, too.
Did you recently pass some significant number on the odometer?
I had a truck where the check engine light was programmed to come on every 60,000 miles, regardless of whether anything was wrong.
Disconnecting the battery cable then reconnecting it can reset it for you. Of course then you’ll have to reset your clock and radio presets.
I would first make sure the gas cap is on properly – this is the most common cause of the check engine light being on. All modern cars do a pressure test of the fuel system on startup when the tank is between 3/4 and 1/4 full. The light comes on if a leak is detected three times in a row.
Remove the cap and check the sealing surface. There is a chance the cap needs replacing. If it looks fine, put it back carefully. If this was the problem, the light will go out after three restarts when the tank is between 3/4 and 1/4 full. You have to allow the car to run for at least several minutes so the pressure test can be completed.
That was on older cars that had a maintence reminder light at 30.000 miles to replace the oxygen sensor. Modern cars no longer have these lights. Wha the OP is describing is more properly known as a Malfunction Indicator Light (MIL) AKA the check engine light.
The first sentence is completly correct. Delete the word pressure and the references to 1/4 and 3/4 and the second is also correct. Some car makers use vacuum, not pressure, and some test at levels above 3/4 and below 1/4. The third sentence is incorrect. Some cars will flip the light after one failed test, some two and there probably are some that go to three before they flip the MIL on.
Whle there is a chance the cap has failed, it usually is a poor installation that causes the MIL to light. As far as the three restarts goes, this is not a true statement for all cars. It can be next to impossible on some cars to get the @!%&%^*$ MIL off after a loose gas cap. You cannot make a blanket statement that three restarts will do it.