Cary Auto Repair

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You would think that most drivers, if a check engine light came on, would take their car into be serviced right away, because it says “Check Engine”. But as you know, if you’ve been driving awhile and owned a few cars in your lifetime, that doesn’t always happen. People are busy. Sometimes money is tight. And if the car is still driving and seems okay, it’s easy to justify not taking your vehicle in. And the more days, weeks or even months that go by, the easier it becomes to rationalize.

Understand that the “Check Engine” light has two urgency levels. The first is a constant message light. This indicates something is wrong and requires attention, but you can safely make it to your destination. The more urgent light is a flashing “Check Engine” message light. If your check engine light is on and is flashing this must not be ignored. It is indicating a severe issue with your vehicle and continued driving may cause serious damage to the engine, transmission or other components of your vehicle.


You may be thinking…“The car is running fine.” I don’t want to complicate my life with a big car repair bill. I have this money in the bank, and if it ain’t broke, don’t fix it.” But the problem with that thinking is it probably is broken! So, yes, fix it. And taking your car in now may save you from a far, far bigger car repair bill in the future.

At Milex Complete Auto Care/Mr. Transmission, we get passionate about every car repair because we really do want to save people money, and we’re bringing up the check engine light dilemma because of the annual CarMD Vehicle Health Index that came out last year. It confirmed what we’ve always said – if you ignore the check engine light, the best-case scenario is that you drive getting less miles per gallon. The worst case? A lot of expensive car repairs.

The Car MD Vehicle Health Index offered the top 10 reasons a check engine light may come on. If that dreaded light comes on, you may need to…

  1. Replace O2 sensor(s)                        
  2. Replace ignition coil(s) and spark plug(s)
  3. Replace the catalytic converter
  4. Inspect the fuel cap and tighten or replace as necessary
  5. Replace the evaporative emissions (EVAP) purge control valve
  6. Replace the mass airflow (MAF) sensor
  7. Replace the ignition coil(s) – but not the spark plugs.
  8. Replace the evaporative emissions (EVAP) purge solenoid
  9. Replace the fuel injector(s)
  10. Replace the thermostat


There is a lot of good news in this list. As you’ll notice, one of the top 10 reasons a “check engine” light comes on isn’t because you need to replace your transmission or four tires. The reasons for a check engine light coming on often involve pretty simple, inexpensive fixes, or even free – if you, for instance, just need to tighten your fuel cap.

But the bad news is that if you don’t take your car into be looked at, you may be soon facing  bigger problems. For instance, take replacing your car thermostat, which came in at number 10. With most cars, you are likely to never have a problem with your thermostat. It won’t ever need replacing. But if it does need replacing, and you don’t get a new one, you might as well just go to your favorite car dealership’s website and start researching new cars.

That’s because your car’s thermostat regulates the amount of coolant that is recirculated back into the engine and determines how much is cooled by the radiator before being recirculated. In other words, your thermostat insures that your engine operate at an appropriate temperature for safety and efficiency. Having a thermostat that sticks open will cause the engine to take a long time to warm up. If it is in the winter, you may not be able to get then coolant hot enough to provide heat inside the vehicle. The engine will also run cooler than is recommended and will hurt your fuel economy and overtime your catalytic converters. If the thermostat sticks closed, your engine will quickly overheat. If your car overheats, you have a major problem on your hands.

An ignition coil is another good example of something that is a straight forward and, in most cases, simple repair. Generally, a few hundred dollars, though it depends on the car.  While that isn’t cheap, it is compared to the alternative of a misfire from a faulty ignition coil severely harming your engine and or transmission. You can see how not replacing the ignition coil could be a very expensive decision.

So, look at and listen to your car. If that check engine light comes on, please don’t put off bringing in your car to Milex Complete Auto Care / Mr. Transmission to have our folks take a look. As always, our initial inspection is FREE. We know taking your car in when you weren’t planning to and facing a potential bill isn’t anyone’s idea of fun – we don’t like doing it either – but it’s better than one day realizing your car has left you stranded. You can only ignore that check engine light until there’s no ignoring it.


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