Diesel engines are notoriously smoky, producing much more blue, white, and black smoke than their gasoline-powered counterparts. The fundamental reasons for this are that diesels operate at higher pressures, with lower-purity fuel, and variable fuel-air ratios. This post covers the different types of smoke, and their (complicated) causes.
Why Diesels Blow Smoke, and What it Means Read More »
Almost every compression testing guide tells you to hold the engine’s throttle wide open during a compression test, but most won’t tell you why it may (or may not) matter.
Why Hold the Throttle Open During a Compression Test? Read More »
Long and short-term fuel trim are very useful indicators of engine performance relative to the manufacturer’s specifications, but before we get into what they tell you, we’ll go over what they are.
Long Term Fuel Trim and Short Trim Fuel Trim Read More »
There are a few different tests for oxygen sensors (also known as lambda sensors), some of which can be run without dedicated tools. The most effective tests tend to be done under normal operating conditions, on a sensor installed on an engine system, though there are some tests which can be done off-vehicle.
Testing Oxygen Sensors Read More »
Glow plugs are installed on many diesel engines to help with cold starts. They usually fail because of corrosion, overheating, mechanical damage, or metal fatigue, and their failure can cause a variety of problems. The easiest way to test a glow plug is by using a clamp-meter, though digital multimeters can also do the job, and glow-plug testers also work.
How to Test Glow Plugs Read More »
One of the questions we hear most often is ‘what is a wasted spark?’. Wasted sparks are also known by many other names, including ‘waste sparks’, ‘exhaust sparks’, which adds to the confusion.
What are Wasted Sparks? Read More »
Most battery testers have two clips (or test leads), you first attach these to the battery’s terminals (connectors), then you press a button (or switch), and a few seconds later, the tester displays or prints a result indicating the battery’s condition. The details of how you use a battery tester depends on what kind of battery you have, the electrical system it is connected to, and which tester you plan to use. Some battery testers require disconnecting the battery from the vehicle, while others have different limitations. Most battery testers only work on one, or a few different types of batteries. We describe how to use five different battery testers below:
How to Use a Battery Tester Read More »
