What is a Turbocharger Assembly?
Naturally aspirated engines suck air directly from the atmosphere by means of vacuum. This vacuum exists because the pistons in the engine pull air in when they move down, just like a very large syringe. This is effective, but in order to gain greater power and efficiency from a small engine, a turbocharger is used to force air into the engine, so instead of the engine pulling in air by vacuum, the engine is receiving pressurized air from what could be considered a powerful turbine.
How does a Turbocharger Assembly work?
As the engine runs normally, the exhaust from the engine does not go directly to the exhaust pipe as normal, instead, it is forced through the hot side of the turbocharger. On this side of the turbocharger, there is an impeller that is blocking the passage of the exhaust gas. Once pressure build, the impeller is forced to spin, allowing the gas to escape into the exhaust system, and out of the tail pipe. This hot side of the turbocharger is sealed from the cold side (compression side), but the impeller is connected by a shaft to the compression wheel on the cold side. As the exhaust gas forces the impeller to turn the shaft on the hot side, the compressor wheel begins spinning extremely quickly. When the compressor wheel begins spinning, air is sucked in from atmosphere, through the air filter, and crammed into the intake manifold at high pressure. This creates a situation in the engine that allows far more air to enter the cylinders, which in turn allows far more fuel to enter the engine on each combustion cycle. This allows more power and engine speed to be made with less application of the throttle, and actually has been used extensively to either make large power, increase fuel economy, or both.
What are the symptoms of a bad Turbocharger Assembly?
Turbochargers need oil from the engine to continue running at the extremely high speeds they are designed for, so when the oil seal breaks, they spit blue-black smoke from the exhaust pipe at an alarming rate. Also, a rattling and scraping noise may be heard from a turbocharger if the bearings fail as the turbines (impeller and compressor wheels) are able to rub against the inner housing of the turbocharger. Finally, turbochargers use a wastegate to vent excess exhaust gas, preventing overpressure to the engine. When the wastegate fails, it is notorious for rattling at a certain RPM range. Other than these symptoms, power loss and oil consumption are by far the most common symptoms. A turbocharged vehicle with a completely failed turbo may not be able to start or idle, and the check engine light will certainly be displayed if the engine runs at all. Lastly, in the early stages of failure, the fuel economy of the vehicle will fall, and the catalytic converter could become ruined from excess fuel in the exhaust.