One of the most difficult tuning problems to overcome is the seemingly ever-present engine vacuum leak. Vacuum is an important component of the internal-combustion process because it controls basic ...

In my 35-plus years of working on cars, I have encountered nearly every frustrating troubleshooting problem in the book. Part of the issue stems from my affinity for old Jeeps and classic cars, which ...

The pumping of an engine’s pistons creates a vacuum in the cylinders, and that vacuum is filled by air drawn in through the intake system. If leaks develop in hoses or engine parts downstream from the ...

When we think of a vacuum leak we generally think of a car that just doesn’t want to run quite right. Most normally aspirated internal combustion engines rely on the vacuum created by the pistons to ...

Your car’s performance depends on precise control of air, fuel, and spark, and vacuum leaks quietly disrupt that balance. When unmetered air slips into the intake system, the engine computer receives ...

Q: I have a 2013 Hyundai Elantra with 84,624 miles. The dealer recently replaced the engine under warranty. When I picked up the completed car, the check-engine light came on within a couple of miles.

Hot rods are meant to be enjoyed. So when it comes to driving your street dream, it must run properly. Few things are more aggravating than an engine that hunts, sags, and generally runs poorly at ...