the death of the shade tree mechanic

 

A shade tree mechanic is any mechanically inclined individual (and it was not always guys) who could repair any automobile just about any place – and it could be outside under a tree.

Today’s cars have gotten both more expensive and more complicated.

 When I was a young man, I did a lot of mechanical repairs on my cars, in addition to regular washing and waxing

The mechanical part consisted of doing my own oil changes, rotating the tires, and replacing exhaust systems and brake pads. It also included the “tune up”, which meant changing the plugs and the points, and setting the timing and dwell angle, which entailed using something called a “timing light”.

(The owner’s manual for my 1972 Opel recommended a tune-up every 6000 miles. Today, platinum tipped spark plugs last 100,000 miles.)

Recommended intervals for oil changes were every 3000 miles, but a few people I know did the task every 1000 miles.

(Most cars today use synthetic oil, which means oil change intervals can be 6000 miles or more).

At some time in the ‘80’s, car companies added “diagnostic panels” to the firewall that allowed mechanics to use a computer to help diagnose mechanical problems.

Things are much different today, which I learned yesterday.

Our car has been roughly idling for the last couple of weeks, and today, the “check engine light” came on, so I took it to my local repair shop today.

If you are keeping score at home, consider this:

Cars first got rudimentary "idiot lights" (warning lights) in the 1930s from Hudson, but the modern, diagnostic-linked Check Engine Light (CEL) emerged with early computerized systems in the 1980s, becoming standardized and mandated for all cars in the U.S. with the OBD-II system in 1996 to meet emissions regulations. 

Computers today do a lot more than simply aiding diagnostics. 

Modern cars contain a vast number of computer chips, typically ranging from 1,000 to over 3,000 semiconductors, with electric vehicles (EVs) and high-end models often having more. These chips control everything from engine timing and safety systems (like airbags, ABS, ADAS) to infotainment, climate control, and battery management in EVs, making cars complex "computers on wheels". 

Key Numbers & Trends:

• Average Car: Over 100 microchips, often 1,000 to 3,000+.
• Electric Vehicles (EVs): Require even more chips for battery and motor management.
• Luxury/High-Tech Cars: Can easily exceed 3,000 chips and have dozens of computers (ECUs).
• Growing Demand: Chip content increases with features like advanced driver-assistance systems (ADAS) and connectivity. 

What They Control:

• Engine & Transmission
• Safety Systems (Airbags, ABS, Stability Control)
• Infotainment & Connectivity
• Climate Control
• Battery & Motor (in EVs)
• Sensors for ADAS (Lane Keep Assist, Adaptive Cruise Control)

Taiwan makes the most computer chips, especially the most advanced ones, thanks to Taiwan Semiconductor Manufacturing Company (TSMC), which produces over 90% of the world's leading-edge chips for companies like Apple and NVIDIA. While the U.S. leads in design, and China is a major producer of less advanced chips, Taiwan's foundry model and robust supply chain make it the dominant manufacturing hub, with South Korea also a significant player. 

Evolution of the Check Engine Light:

• 1930s: The "Idiot Light": The Hudson Motor Car Company introduced simple warning lights for critical issues like low oil pressure or overheating, but they offered no specific details, just a binary warning.
• 1980s: Early Computerization: As cars became more electronic, early versions of the CEL appeared, linked to proprietary manufacturer diagnostic systems that could flash fault codes, though they weren't standardized.
• 1996: OBD-II Standardization: The U.S. government mandated On-Board Diagnostics II (OBD-II) for all vehicles, creating a universal connector and standardizing Diagnostic Trouble Codes (DTCs), making the CEL more informative and diagnostic tools universally applicable. 

What I learned today is that repair shops have also started to use artificial intelligence to simplify the diagnostic process, which makes it faster and cheaper than prior methods.

Naturally, the costs of maintenance are a lot more than they used to be.

To get our car running smoothly again, the repair garage replaced 4 spark plugs and one of the 4 ignition coils. The spark plugs were $31.36 each, but that single coil was $463.48. which brought the total bill (including labor) to a little more than $1100.

“What is a coil?”, you might ask.

Ignition coils act as high-voltage transformers, converting your car's low battery voltage into the thousands of volts needed by the spark plugs to ignite the air-fuel mixture in the engine's cylinders, powering your vehicle. By creating a strong electrical spark, they initiate combustion, and without them, the engine can't run, leading to misfires, poor performance, or a no-start condition. 

 

An ignition coil is used in the ignition system of a spark-ignition engine to transform the battery voltage to the much higher voltages required to operate the spark plug(s). The spark plugs then use this burst of high-voltage electricity to ignite the air-fuel mixture.

The ignition coil is constructed of two sets of coils wound around an iron core. Older engines often use a single ignition coil which has its output directed to each cylinder by a distributor, a design which is still used by various small engines (such as lawnmower engines). Modern car engines often use a distributor-less system (such as coil-on-plug), whereby every cylinder has its own ignition coil.

 I still wash our car on a regular base, and I wax it 4 times a year to protect the paint from Tucson’s summer heat – but my days as a shade tree mechanic are now a thing of the past.