Turbochargers are becoming increasingly popular in new vehicles, regardless of make and model due to increased emissions standards and the necessity for smaller displacement engines.
Being an integral part of an engine in which they are placed, turbochargers can wear out and fail like any other engine part. Loss of performance, unusual noises, burning oil, and the check engine light are all signs that it has finally happened and a trip to your local mechanic should be on your to-do list.
What Is a Turbocharger or "Turbo"?
A turbocharger is a device fitted to an engine that uses its exhaust gas to spin a turbine, sucking air into the vehicle’s intake. The turbo then sends compressed air into the engine, creating more power. This is called forced induction, and the greater amount of compressed air that is forced into the engine creates more power than the vehicle can produce without the assistance of one of these systems.
Common Signs and Symptoms of a Failing Turbo
As turbochargers become used more as a result of shrinking engine displacement, the possibility of turbocharger failure also increases. There are several prominent signs – and some that are not as prominent – that signal a failing or blown turbocharger.
Not all of these signs and symptoms are specific to turbochargers, but none should be taken lightly. It is important to trace the root of each problem to its source to correct any issue your vehicle might be experiencing.
Loss of Performance or Power
A blown or failing turbocharger can have a prominent effect on acceleration and overall power, though some vehicle performance factors like handling and braking are not affected. This is because one of the two primary jobs of a turbocharger is to provide additional power to an engine that, without a turbocharger, would not be as powerful.
You know your vehicle best, and a loss of power or acceleration should be fairly noticeable. Although a loss of engine power and slower than usual acceleration could be attributed to many other engine-related issues, a failing turbo could be one of them. More than one sign of turbo failure is usually another good sign of a turbo-specific issue.
Excessive oil consumption or the burning of oil is another sign of turbocharger failure that could also be the sign of another unrelated engine issue. Turbos use oil – like most other moving parts of your engine – to operate smoothly and effectively. A cracked seal, gasket, or even when the turbo itself is cracked or damaged, oil could leak from turbo components.
Visible Exhaust Smoke
When oil leaks from the turbo, it can often leak into the exhaust system of your vehicle. As it does, the hot exhaust burns up the oil and creates blue or grey smoke. Vehicle exhaust is normally colorless.
Excess oil consumption and visible exhaust smoke often go hand-in-hand, but again, neither are sure signs of turbo failure. Faulty head gaskets, leaking valve gaskets, and other internal engine issues are some other popular causes for oil burning and thus, the production of colored exhaust.
Increased Fuel Consumption
An engine is designed to run smoothly and efficiently. When components fail or degrade over time, efficiency is lost. The second, lesser-known job of a turbocharger is to help increase engine efficiency by adding power without using direct engine power to make it run.
Air coming into the engine must pass through the turbocharger to get in. If there is an issue with the turbocharger, air will not pass as efficiently as it needs to through the turbo. Additionally, exiting exhaust gas that cannot power the turbo properly because of an issue will not be able to power it. The result is the overall hindrance of the engine to run smoothly, increasing fuel consumption.
Check Engine Light
The illumination of the check engine light is the obligatorily advertised sign of just about any engine-related issue. But, despite its myriad of potential implications and its reputation for being ignored, it is always important to have the cause of the light diagnosed. This can often be done for free at many automotive retail locations.
An error code specific to your turbocharger will display if it is the cause of the fault.
Boost Gauge Indication
Boost gauges are usually installed as aftermarket components and can come from the factory on sportier cars, but they are not common on most normal vehicles. But, they can be a more direct indication of turbo failure if they show that boost is not building or holding at normal levels.
They can be installed on most vehicles, but aftermarket installation is usually reserved for performance reasons rather than practical reasons.
As mentioned before, oil can leak through a cracked turbo or its gaskets. Most of this oil will be burned up before it leaks from the turbo, and many stock vehicle turbos are deep in the engine bay where visible oil dripping may be hard to detect. Even still, oil leaks are cause for concern that should be traced and rectified as soon as possible, even if the source of the leak is non-turbo related.
Change in Turbo Noise
All turbochargers make some sort of noise. Many stock turbos on normal vehicles are hardly noticeable and very faint. Normal turbo sounds include a whooshing or faint whistling. Large turbochargers like those found on diesel pickup trucks and big rigs make a much louder noise. Performance cars with large turbos can also be heard prominently as they rev.
A change in these types of noises can often signify a turbo issue. Noises like rattling or humming are not normal. A sharp decrease or significant increase in normal turbo noise should also be cause for concern.
Another prominent, abnormal turbo noise is the whining of a blown turbo. It sounds very similar to an engine belt being spun too fast, a siren, or even a supercharger. This is the most direct and telling sign that your turbo has had it. If this happens, you should immediately have your vehicle seen by your local mechanic.
What is the Expected Lifetime of a Turbocharger?
There is no hard and fast answer to how long a turbo will last since they are like any other engine component that could fail from several different causes; however, it is expected that most stock turbos will last the lifetime of the car in which they are equipped. Estimates of between 100,000 and 150,000 miles of life with good maintenance practices are common.
Beyond excess wear and tear, several things might cause turbochargers to fail prematurely. The most common of these is the lack of lubrication from oil starvation. This could cause turbos to overheat, ultimately destroying them. Oil starvation could also be caused by leaking turbo seals and gaskets. Because they spin so quickly, a good oil supply is vital to their proper function.
Another common reason for premature turbo failure is debris and foreign objects, particularly, contaminants that come through and from the engine. The air filter is supposed to catch any outside contaminants that may get into the engine and harm it, but carbon buildup especially can exit through the exhaust and get into a turbocharger, eating away at it over time and causing it to fail.
Oiling issues and contaminants are the cause of the vast majority of turbocharger failures, but things like over-revving, hard acceleration when the engine is cold, and excess idling time can also contribute to premature turbo failure.
How Much Does a Turbocharger Cost to Replace?
Turbocharger replacement costs can vary quite a bit depending on location, vehicle make and model, turbo size, turbo location within the engine bay, and the repair location. Smaller vehicles with small, easy to access turbos will cost less to repair than large vehicles with big turbos that require a lot of labor time to access.
Typically, turbocharger replacement can range from $1500 to about $4500 when all of these factors are considered and added to the labor costs, taxes, and shop fees. On average, therefore, a full turbo replacement will cost between $2500 and $3000. Variations in any of these factors can cause the overall cost to fluctuate greatly.
The use of turbochargers is becoming ubiquitous, especially in newer vehicles that require lower engine displacement to offset emissions. That being said, it is important to know the signs and symptoms of a failing turbo so that engine damage can be avoided. Decreased engine performance, excess oil consumption, and unusual turbo noises are all signs that you should not ignore. Make sure to take your vehicle to a mechanic should any of these symptoms occur to avoid a costly problem down the road.