Diesel Tuner's Blog

Boost Testing your diesel is essential!  Common symptoms of a boost leak include Increased Smoke, Higher EGTs, Excessive Lag, and Loss of Power.  Every truck that comes in our shop here at Calibrated Power, gets a boost test.   It seems about 85% of them have a boost leak when they show up.  Most of the time customers report still seeing peak boost on their gauges despite a boost leak. 

If you work with diesel trucks long enough, you’ll see leaks just about everywhere in the charged air system at one time or another. Remember, the charged air system includes anywhere from the turbocharger to the intake manifold. Your Intercooler system, Exhaust Gas Recirculation components, and even the Turbocharger compressor cover can all develop boost leaks.

Does your diesel have High EGTs, Excessive SMOKE, Increased Turbo Lag, and Less Power than it used to? Let’s talk about boost leaks.

Your truck needs air! Not a little bit of air. Your diesel engine needs all the incoming air it can get. Increasing air in the combustion process will help manager your Exhaust Gas Temperatures, Limit your smoke output, and increase your power.

This is why boost leaks kill diesel engines. Boost leaks can result in a smokey, laggy, dog-of-a-truck, which runs hot and burns fuel. Basically, the exact opposite of what you want from your diesel.

Boost leaks commonly occur in boots and clamps throughout the charged air system. That’s anywhere from the turbocharger to the combustion cylinder. Your intercooler system, Exhaust Gas Recirculation components, and even the turbocharger compressor cover can all develop boost leaks over time.

Too often trucks come into our shop experincing high EGT's, turbo lag, excessive smoke output, and bad fuel mileage which are all symptoms of a boost leak. It is so common to develop a boost leak that we now require all trucks to have a leak down test done prior to strapping them down on the dyno. What's funny is, most truck owners that we do identify boost leaks on never even knew they had one. The reality is that even if you can hit peak boost, you may have a leak, especially if you have a variable vane turbo. Variable vane turbos will change vane position and other operations to try to compensate for the reduced level of boost pressure in the intake system. Leaving you driving around without an idea that your turbo efficiency has taken a hit.