Horseshoes and Hand Grenades 

       Sometimes accuracy isn’t all that important, such as in a game
 of horseshoes or tossing a hand grenade. But the same can’t be 
said for diagnosing today’s cars. Close isn’t good enough. Today’s 
professional mechanic doesn’t just grab a component hanging from 
a branch of the proverbial parts tree and see if that will fix the 
problem. It requires a diligent effort of testing and diagnostic 
time to analyze the maze of electronic data. That’s not to say a 
consumer won’t stumble across a repair shop that still uses the
 hand grenade method in diagnosing their car. Believe me, they're 
still out there.

      Basically, there are two types of mechanics a consumer will 
run into. One that will test and retest before condemning a 
component and the other that will swap parts until they’ve solved 
the problem, or they give up and send the customer to the other type 
of mechanic. The worst part about it all, is the customer has more than 
likely paid for loading that parts cannon and has paid for those failed efforts to hit
the target. 

  To avoid the typical slinging of the horseshoe, a good shop will listen to the customer’s complaint, follow the diagnostic procedures and base their findings on the test results. Just to be sure, when faced with those problems that don't arise very often, a professional mechanic may even perform two completely different testing methods and compare the results. It’s a far better way of solving a problem than firing the old parts cannon at a job. 

  For example,  if you take a look at an instructional video or go to any training class, they’ll show you how a component or system functions and then how to test for failures. They might use a scanner, perhaps a scope, or even a basic multi-meter. But, every situation the concept is to show the technician the various ways of testing. These methods may vary but the results are the same. Be precise with your testing methods, and the results will follow. The thing that always was hard for me to understand was that I've never watched a training video that told you to fire up the parts cannon and take a wild shot at problem rather than testing for the failure. So why are there so many parts swapping repair shops in the automotive repair business? 

  In my opinion, it’s the lack of training, they don't want to make time for advanced classes, or they believe they can get by without staying up with the ever changing technology. Most of these shops are all about how fast they can get a customer in and out the door, and use hearsay and grapevine information to solve these problems.  They’ll spend as little time as possible diagnosing, while spending the majority of their time calling the parts store or asking someone else(via internet most likely) what they believe the solution would be. The sad part is, eventually, they’ll hit the target. Usually resulting in affecting the consumers pocket book and their confidence in the automotive industry. But, that's changing... with the advent of the advanced electronic systems these days, all this parts swapping may be coming to an end. 

  Today's vehicles have the capability to 'learn' the degradation and slight variations in worn parts by making small adjustments through the on board computer systems. By the time a service code has been set the problem may actually be compounded by failures in other systems. Basically, swapping one part for another may actual throw the entire computer logic into a tail spin. Because the computer now will make adjustments based on those swapped out parts and will either have to relearn a new strategy (misfires, high idles, shift points erratic, etc...) or fail to operate until the mechanic finds that actual root cause.

  As far as these 'parts-swapper' shops thought process in regards to running their business, they don't want to take the time to hire qualified technicians. They would rather hire someone with a tool box that can still walk upright and fog a mirror. Then take their chances with their new tool box delinquent. Training isn’t cheap, and a trained technician isn't cheap either. Proper testing and well educated technicians takes time, which invariably costs money.  

  Then to top it all off, most of these places will use second rate components from the local discount auto parts store and not a mechanics grade or OEM level component. The average consumer doesn’t know which part or brand is better than the other. They’re relying on the mechanic and the shop to sort that out for them, and at these shops, you can bet the quality of the part is going to be in question. They just want it as cheap as possible and as quick as possible. But when the parts merry go round doesn’t do the trick, they’ll send the customer on to one of those other guys. You know, the ones that will test things first. 

  Of course, by the time the customer has reached a shop that will correctly test the problem they’re already out of cash and have little to no confidence that anyone can fix their car. Now the problem isn’t so much about the cost of the parts or components, but the diagnostic fees. Of course, all the customer has to base their evaluation on is the last guy who threw all these parts at their car, and obviously (to them) you (the trained mechanic) are no different than 'Parts Swapping Pete'. 

  I’ve got to hand it to these stab in the dark parts shops, and those parts stores offering free code checks. They’ve got the market cornered on convincing the consumer that all it takes to fix today’s cars is a quick glance at some off shore generic code reader and a couple of cheap components from a third world country. Never mind that there are pages and pages of diagnostic procedures that go along with those service codes. Which leads to the usual angry customer and the typical conversation at the service counter, “I’ve already had it tested, so I don’t need to pay you to test it again.” Now that’s funny. Getting it tested and diagnosed correctly is exactly why they are here in the first place. So why am I the bad guy in all of this? 

  A good example of this was a rather heated customer whose car had a miss after a tune up at another shop. The other shop had already tossed a parts grenade under the hood. They tried sensors, computer, the tune up, and just about every other part they could think of. The tech at the new shop looked it over with his scanner, and to back up the scanner results he pulled out his scope and checked it in a completely different way than what the scanner could. 

  Looking at the secondary ignition trace, this trained technician could clearly see a problem directly associated with a spark plug. The entire problem turned out to be a brand new spark plug that had a slight crack in the porcelain. 

  Now how long did it take to make the actual repair? You know, replacing one easy to reach spark plug that the original shop had already replaced? Not long at all. But, how long did it take to set up the scope,do the testing, and verify the results? Probably twice as long as it took to change the plug. Just goes to prove that diagnosing is a bigger part of the repair procedure than ever before and shouldn’t be overlooked just to cheapen the job.

  Parts swapping without testing, or simply going off a code as a solution to today’s car problems, is like playing with horseshoes or hand grenades. You’re going to get it right some of the time, but that’s just sheer luck, and with these new designs and engine configurations, swapping parts maybe more time consuming than performing the actual tests. In the long run, the trained technician is not only a must in the industry, but a must for the consumer... it's just good business.