Recently the check-engine light on my 2000 Lexus ES300 lit and began flashing. My car also began to run sluggishly and felt like it was going to stall. I took it to a mechanic who told me one of the ignition coils was bad. He then told me that as they are randomly fired, there was no way to determine which coil was bad. He said I needed to replace all 6, as well as recommending I replace the spark plugs too.
Was he right, or did I replace 5 good, functioning coils and plugs (total cost of 800.00) unneccesarily?
Randomly fired was a great one. Nobody would believe that, yet he said it. The code he read should have given a hint, or more than likely, pinpointed the problem. You probably got cheated $550.
Well, this mechanic was listed (or at least the service station) on Car Talk’s website under “find a great mechanic.” So I was more trusting than usual. Does anyone else have any specific knowledge of the ignition coils on a 2000 Lexus ES 300?
wires i can see for sale for $50 to $120.
Coils come either 6/engine or 3/engine depending on engine type, for $80-100 per set.
While it does sounds like an ignition problem, unless there was some misunderstand coils don’t randomly fire, they are very ordered and very precisely timed.
Assuming you are no longer having problems, at least it was fixed, but it sure sounds like he did more than needed.The mechanic should have been able to determine which was misfiring. The OBD-II codes should have told him. And, while each plug now has its own individual coil (called a “distributorless ignition” or a “coil-on-plug ignition”, which one is firing can be ascertained. And, as others have pointed out, the timing is precise…the complete opposite of random.
If these were the original sparkplugs they were overdue anyway. And it’s possible that the problem was a plug. Normaslly I wouldn’t second guess this kind of thing, but because of what he said about the coils I find myself wondering.
I guess if the car is now running well all you can do is write it off to experience and find another shop for future use.
Perhaps you misunderstood? Or maybe the mech is a goof. The condition is typically called a random misfire. It should be fairly easy to pinpoint the affected cylinder(s) versus the shotgun approach used.
You can provide comments about the shop in question. There are comments from customers in the Find a Mechanic section, so you should be able to describe your experience, too.