How To Test for Boost Leaks the Easy Way!
Experiencing Power Loss? You May Have a Boost Leak!
So you're crusing down the freeway and go to pass a car who's travelling under the speed limit. You lay the hammer down, but notice the car doesn't have what it used to. You start to panic, afraid that something terrible is wrong the car. Fret not, as you could be experiencing something that most turbocharged car owners will experience at least once in their lifetime: a Boost Leak!
Symptoms of a Boost Leak
- Slow Spool
- Loss of Power
- Poor Idle (MAF cars only)
- Erratic Timing / Injector Pulse (MAP cars only)
A boost leak is simply weak coupler, cut vacuum line, or loose clamp that cannot support the amount of boost you're running, therefore causing a leak in the charged system. While typically remaining harmless aside from loss of power, a boost leak that goes ignored can cause stress on the turbo which will drastically reduce the life of the turbo.
Fortunately, it's not the end of the world. There are many methods you can use to make finding a boost leak much easier including a handy boost leak tester, and we'll cover them all below to ensure you find that pesky boost leak, and get back on the road in no time!
Visually Inspect All Couplers and Clamps
This is the most common source for boost leaks, and usually happens after installing bolt-ons or other modifications that require the removal of the charge piping. Sometimes we forget to tighten the clamps down after finishing the project. It's nothing to worry about, you're most likely excited to test out the car so we'll excuse this mistake.
Starting at the compressor housing, work your way towards the intercooler and up towards the throttle body. Check all couplers for holes and all clamps in between to see if they're on good and tight. A good method of insurance is to replace all ring-worm clamps with t-bolt clamps for ultimate clamping power and to reduce the risk of the clamp chaffing a hole in the coupler. If all of these are in good condition, head to the next step!
Visually Inspect All Vacuum Lines
This is another area that commonly goes un-noticed until a boost leak is discovered. Some gauges and aftermarket bolt-ons require removal and relocation of important vacuum lines. If left unplugged, these vacuum lines will most likely cause annoying boost leaks. If you've installed an aftermarket boost gauge, boost controller, or wideband, and have boost leak symptoms, these will be the first places you should check.
Starting at the compressor housing, check the vacuum line that leads to the wastegate controller. Make sure you have clamps on all fittings, and ensure that the vacuum line is of the correct size (this is important for a tight seal). If you have any vacuum T's, check for leaks here and to be safe, replace with a steel T. Trace all lines from the turbo to their ends, looking for cuts or kinks in the line.
Use a Boost Leak Tester to Test the System
A boost leak tester is a great little tool for testing if you think you have a boost leak. It will do everything mentioned in the past two steps all at once, so it's a great idea to purchase one as it will save tons of time.
A boost leak tester allows you to pressurize the system without having to start the car or bring it up to load. Simply remove the turbo inlet, attach the boost leak tester, hook the tester up to an air compressor, and allow the system to pressurize. From there, you can listen for leaks, or spray windshield washer fluid on your couplers/vacuum lines and look for bubbles that would indicate leaks.