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 »
