(I wish to again thank all the customers that have expressed appreciation  for my recent articles.  It has proven to be a conduit for me to voice and share my personal thoughts on automotive and other issues).
 
   
 Recently, one of our Vocational students was assisting a technician performing a tune-up on a customer's late 80's GM car. The student was comparing the three spark plugs that came out of the front three cylinders to the three spark plugs that came out of the back three cylinders. The student found it strange that the electrodes on the three rear spark plugs had worn clean off, yet the front three plugs still had some visible electrode remaining. In addition, the rear plugs seemed older than the plugs in the front. Our technician knew the cause since he had seen it before. It was one of those unfortunate things about this industry that you have to explain from time to time. The customer had another shop, or person, tune the car up in the past. But what they didn't know was that they actually got ½ a tune up. The rear spark plugs on this type of front wheel drive vehicle are extremely difficult to change. Since the car is front wheel drive, the engine is mounted transversely instead of front to back. The front plugs are facing the radiator. The rear plugs face up against the firewall. You literally have to contort your arm and hand into painful positions to access those rear plugs. Think we're kidding? Ask anyone that has done them, they will show you the scar tissue. Even though the customer had paid for a tune-up in the past, the rear plugs were never changed. We'd like to see the old invoices on some of these blundered jobs. Bet there are six plugs billed out on the slip! Since the rear plugs had not been changed in more than 70,000 miles, the electrodes were worn off. Not only is this a shoddy tune-up job, it also has the potential to be very costly to the owner. This can cause premature ignition coil and module failure. Since the spark has to bridge such a large gap, the vehicle's ignition coil and module have to work at constant full output. This is not something they are designed to do. Some of these coil/module combos are more than $500.00. It is cheap insurance to replace spark plugs at the proper intervals and make sure the person doing the job can be trusted to do it correctly. 
 

 .