In a nutshell, a turbocharger uses exhaust gases produced by the engine, which are pushed out of the engine at a velocity that corresponds with the speed of the engine’s rotation to push fresh air into the engine. The faster the engine “revs” the higher the volume and speed of the exhaust that escapes it is. Exhaust consists of air and the by products of fuel combustion (carbon monoxide, and a lot of other chemicals).
In a normally aspirated engine, air is taken in at atmospheric pressure. In a turbocharged engine, air is pushed in to the combustion chamber under pressure. Because the air is compressed, more fuel can be introduced into the engine while still maintaining the ideal mixture ratio between air and fuel. Simply put, being able to put more fuel into the engine results in more power.
Because the exhaust gases would be emitted anyway, harnessing them to increase performance also increases efficiency. The turbocharger plays a big role in making diesel engines the powerhouses that they are.
Unfortunately, the high temperatures and speeds involved in a turbocharger can be hard on it. The turbine is the component that hot exhaust gases push against to drive the unit. It’s subject to extremely high temperatures, and speeds up to 150,000 rpm. The compressor wheel “squeezes” air into the compression chamber. When air is compressed, it gets hot. Even at the “cool” end of the turbocharger temperatures can exceed 200 degrees Celsius.
The turbocharger needs a healthy supply of engine oil to lubricate its moving parts, and to help cool it. Often, an impediment to oil circulation and/or dirty oil, can cause the turbocharger to fail. In fact, short of component failure in the turbocharger, nearly every turbocharger failure is caused by something else in the engine not working correctly. Air and gas leaks, worn piston rings, clogged exhaust, carbon build-up and a hundred other things can cause turbocharger failure. When this is the case, simply replacing your turbocharger may appear to solve the problem, but it will likely reoccur in a relatively short time.
IAmDIESEL is the Diesel Service Centre at Western Turbo and Fuel Injection in Winnipeg. We’re the area’s premiere diesel service centre. If you’ve experienced a turbocharger problem, bring it to us. Because we understand diesel engines better than anyone else, we will diagnose and repair the root cause of your problem, not just the symptom.