80% of all problems
Customers and Questions
One of the most frequent questions I am asked pertains to the Diagnostic fee. For example:
Customer: “My check engine light is on, it is running kind of rough and I want to know how much it will cost to have it fixed.”
In an attempt to find out where and when the problem occurs, I generally respond with several questions of my own.
Tony: Is the engine light blinking? If the answer is “yes” my first thought is that it must have a miss which is causing the converter to overheat and make the check engine light blink. If the answer is “no”, I can assume it’s a sensor of some sort anywhere from the back of the car to the front. The only way to confirm the location is to plug the scanner in and take a look as to the area of the problem. The car doesn’t tell you what is wrong with it, it just tells you what the computer sees as a problem and sets a code. I notify the customer that the estimated Diagnostic fee can range anywhere from $85.00 to $170.00. If more in-depth study is needed, I call the customer for approval before proceeding. The Diagnostic fee includes a scan of the system/wiring diagrams and a competent man evaluating the car’s problems. Some people understand that today’s car may resemble the car their grandfather drove, but it is very much different. Depending on the car, there are more than 100 sensors and control modules doing everything for you to insure the quickest starts and to obtain the best fuel mileage. Others don’t and this can sometimes present a problem.
I understand that people want to know up front how much their problem will cost but until the diagnostic work has been completed I won’t know for sure. If money is tight but you have $200-$300 to spend at this time, I would advise that you get the diagnostic work done. From this information I can provide you with an accurate estimate. Otherwise it’s just a ‘guess-ta-ment’ and I hate making those. I’m either too high or too low and I’d rather be as upfront and honest with the customer as I can be.
In order for your problem to be rectified the systems need to be checked and this is where the diagnostic fee comes in. Once the problem area is defined the cure is simple!
A customer, we will call Steve, comes in with an oxygen sensor code. He told me that he had (a chain store) diagnose it as a 02 Sensor and he replaced it himself. Now the light is on again. I told him that I understood he previously had it diagnosed but I would have to diagnose the problem myself. He agreed and sure enough he had a 02 code on one side of the engine. The car had four 02 sensors and only two were lean at Idle. Once you increased the speed of the engine they both worked a little. An under hood inspection revealed a vacuum leak on that side so the leak was repaired and guess what, the problem went away. The computer flagged a code for an 02 sensor being lean but the real problem was a vacuum leak making the 02 sensor lean.
Sometimes it is like looking for a needle in a haystack to find the problem. There is only one check engine light that is on but there could be many codes to be reviewed and I will clear them and ask them to come back later to verify the problem, as illustrated in the next example.
A 2003 Minivan comes in with a string of codes that would choke a horse. Codes were cleared and the vehicle was test driven. Once the check engine light came on and codes were pulled only 2 were left Po304 misfire #4 cyl & 204 #4 injector circuit. Compression test was done on #4 and was ok as well as spark. The intake was pulled and the injector was tested 13.5 ohms like the others. Power and grounds were tested - we had power but why was the ground was missing? We checked the injector ground @ PCM and none was found. The PCM driver in the PCM was bad but what knocked it out??? I split the wiring harness to the injectors which revealed a melted (Cooked) wire harness right where it sits above the exhaust manifold (Smart Design). The computer was sent out to be repaired, new wiring harness was purchased and installed and down the road it went. If I had quit looking for what caused the driver to go out, the repaired computer wouldn’t have lasted very long. Sometimes the root problem can’t be found and sometimes stuff just happens, but you have to look.
One of the worldliest men I’ve met, we will call him Harry, dropped of his 2007 Mercury Milan because of a miss on acceleration and @ cruise. I scanned the codes and he had a PO303 #3 cylinder with a miss & PO316 Code 303 #3 Miss @ start-up. The intake was pulled and the burn time was .8 on #3 and 1.9 all others. # 3 spark plug and coil was replaced and all was well.
I hope this explains why I have no immediate answer when asked “how much will it cost?” Until I locate the problem it is difficult for me to answer. Example #1 cost him $85.00, Example #2 cost $1300.00 and Example #3 was less than $500.00.
Today we have a PCM that controls almost everything under the hood from idle speed, the timing of the fuel injectors to the spark advance of the ignition and everything in-between.
A BCM that controls lighting, starting, power seats & windows heater/AC controls or just about everything inside the car. Cars of yester year went in for semi-annual tune-ups where the mechanic would replace the points and condenser/spark plugs and make sure the carburetor choke pull offs were working and the coolant was up to snuff.
Things have changed, today’s cars don’t require the annual tune-ups anymore and they start easier than they ever did. The computer recognizes the outside temperature and PCM adjusts accordingly (no more pumping the accelerator to start or setting the choke,etc). When today’s cars start up your seats move, radio stations change, your idle speed adjusts and your heat comes on. All you have to do is turn the key or push the button.
I pride myself on being able to fix problems with less money than about anyone. Your car has more computer capabilities that the space shuttle and that is why 100° or -20° it always starts the same way, and runs great most of the time.
I hope this helped you to understand why I may seem so evasive on the phone when asked
“How much it will cost?”
P.S. I wonder how much it will cost someone when they loose the transponder to the push button start cars.
Tony Presley / Presleys Garage