2020 Editions Archives - UnderhoodService
Domestic Gasoline Engine Oil Specifications

If it’s been more than a year since last oil change, the IOLM will display a reminder message, regardless of mileage.

Tech Tip: No Start in Cold Weather Due to No Weep Hole

This condition can be caused by condensation freezing in the muffler assembly. Follow this procedure for correction.

Engineering Better Belt Systems

You might not be able to see it, but an accessory drive belt is always both speeding up and slowing down.

Do Oxygen Sensors Generate Electricity?

They are made of zirconium oxide, a chemical compound used to form the sensor’s thermal-driven electrochemical fuel cell.

Inspecting Oil Filters

Cartridge oil filters are easy to inspect, but canister oil filters only give you a limited view.

EGR, Secondary Air Injection And Emissions Management

EGR systems put a small amount of inert gas into the combustion chamber to control the temperatures.

Mini Cooper Water Pump Service

The water pump is turned by a metal wheel driven by the crankshaft pulley.

How To Diagnose Slow or Sluggish Oxygen Sensors

When oxygen sensors are tested, manufacturers will introduce small amounts of oil to measure sensitivity.

Detecting Misfire And Knock Conditions

Knock sensors are mounted on the block near the base of the cylinder head.

Balancing Combustion Forces

Visual inspection is critical. Any sign of movement laterally is grounds for replacement.

Caring For AGM And Flooded Car Batteries

Loose, corroded or damaged battery cables make poor electrical contact and can cause a battery to run down.

Fuel Injector Waveform Diagnostics

On the majority of injectors, an electromagnetic coil is energized by a driver in the engine control module.