December 2019 Archives - UnderhoodService
Check Out The December Issue Of Underhood Service Magazine

Access the interactive and easy-to-view digital edition featuring articles on Fuel-Related Misfires, Secondary Waveforms, Understanding A Data Bus, Diesel Exhaust Fluid, Subaru Stretch Belts, Diesel Oil Filtration, a host of tech tips and more!

History Of Air Power

The air spins up the exhaust turbine and increases boost on the compressor side. The tank pressurizes up to 175psi and has enough volume for two hard acceleration events.

Tech Tip: Alternator And Battery Testing Diagnostic Tips

For some vehicles, it’s normal to see as high as 16 volts for long periods at a time. For others, it’s ­normal to see as low as 13 volts. For some, a constant 13.6 volts is an indication of a problem.

Tech Tip: Replace A Failed Water Pump And Timing Belt At Once

Here are three main reasons why you should have a conversation with your customer to replace multiple parts simultaneously.

Tech Tip: How A Turbocharger Can Be Damaged

A turbocharger is a complex unit with precisely matched components.

Tech Tip: Fuel Delivery System ElectroStatic Charge Problems

Fuel delivery system components concentrate on the use of specific plastics and nylons to reduce conductivity.

Installing Subaru Stretch Belts

When a stretch belt exceeds wear specifications, it’s no longer able to grip the pulleys and will start slipping.

Clearing The Air About Diesel Exhaust Fluid (DEF)

Reducing emissions to acceptable levels is achieved through a four-stage process.

Understanding The Function Of Serial Data Buses

Serial data buses help to eliminate multiple sensors and wiring. One sensor can share information with multiple modules without having to connect directly to the multiple modules.

Scoping Ignition Waveforms

The secret to being able to capture and analyze secondary ignition waveforms is understanding what is happening in the coil and at the spark plug and how the scope measures and graphs the voltages and ignition event.

Understanding Diesel Oil Filtration

Approximately 75% of the contaminants trapped by the oil filter are combustion byproducts, like soot and sludge.

Understanding Misfire Events And Causes

Pre-ignition is very damaging because of two dynamics inside the cylinder.