While they’ve never really been out of style, it’s no secret that turbos are “in” right now. You can literally find one on everything. But with so many different types of vehicles benefiting from this form of forced induction, there are bound to be failures. And in some extreme operating environments, not even items such as wastegates, blow-off valves, ball bearing cartridges, or 360-degree thrust bearing assemblies can keep a turbo from reaching its breaking point.

So if you’re using a turbocharged car, truck, SUV or anything else turbocharged, we’ll show you these breaking points so you can avoid them.

1. Lack of Oil Issues
   Lack of proper lubrication/oil supply will damage the journal and thrust bearings in a turbocharger very quickly. When subjected to a lack of oil supply, the journal bearings will eventually begin to allow shaft play, followed by the compressor and/or turbine wheel making contact with its respective housing. Inadequate/contaminated oil supply can also score the bearing system, as well as cause excessive heat inside the cartridge.

Oil contamination — be it from lack of maintenance, coolant or fuel in the engine oil or debris from an internal engine component breaking down — can badly damage a turbocharger as well. Contaminated oil can lead to all of the problems mentioned above (worn journal bearings, a damaged thrust bearing, or scoring of the shaft),

SOLUTION:

Ensure your engine oil is changed regularly and is always free of contaminants.

2. Foreign Object Damage
   Anytime a turbocharger ingests something — be it dirt, dust, a bolt left in the intake — it can spell disaster. Unfortunately, outside debris making its way across the blades of a compressor wheel (the intake side) accounts for many turbo failures. When this failure occurs, the leading edge of the compressor wheel’s blades will indicate any impact from the object(s), and the inducer bore (what the compressor wheel sits in) may show signs of contact or scarring.
   The most common cause of debris infiltrating a turbo? A dirty air filter. That’s right, lack of maintenance on one of the most basic components on your vehicle can cost you.

SOLUTION:

Use a quality air filter and keep it clean if it’s reusable or fit a new one at the proper service interval if it’s replaceable.

3. Overspeeding
   Once a turbo is forced out of its limits on the compressor map, it may not always produce more boost, but it will almost always create excess pressure, causing the shaft to rotate faster than it was designed to handle. When over-speeding occurs, the turbine (exhaust) wheel is usually the first component to give way, and the compressor wheel backface takes on a whole new dimension. In particular, over-speed scenarios are somewhat common on high performance diesels. Even in completely standard form, a modern diesel pickup can see 30 psi of boost or more. Common causes of overspeeding are mainly due to the tuning fraternity and “upgrades” not performed correctly.

SOLUTION:

Keep your turbo’s boost-to-drive pressure ratio as close to 1:1 as possible (1:1.5 is OK in most cases), which may entail running a wastegate to bleed off excess drive pressure or opening up the exhaust flow via a larger turbine housing.

4. Oil Leaks
   Most modern turbochargers make use of dynamic seals (vs. carbon seals), which help keep the oil being supplied to the bearing housing from making its way into the intake (compressor) or exhaust side (turbine) of the turbo. However, things like excessive crankcase pressure in high horsepower engines, operational wear on the seals or an improperly routed (or undersized) oil drain pipe can lead to oil leaks. Once the cartridge becomes overly pressurized, it can push oil into the intake and/or exhaust side of the turbo.

SOLUTION:

If you have excessive crankcase or oil pressure due to a high horsepower application or breather filters blocked, a better crankcase ventilation system or a dry sump oiling system should be looked into. If you have leakage of oil from an old turbocharger, it could be time for an overhaul.

5. Extreme Heat
   Extreme heat can kill anything, right? Well, the same goes for turbochargers. Prolonged exposure to over 1,000 degrees Celsius will eventually take its toll on the turbine (exhaust) side of the turbo. Common failure points due to heat are: stress cracks in the turbine inlet flange, eroded edges of the turbine inlet volutes and deformation of the tips of the turbine wheel blades.

Common causes of excess heat being generated include: high performance, a restricted exhaust system, cracked intercooler, or even a clogged air filter.

SOLUTION:

Monitor exhaust gas temperature and stay within the recommended heat limits for your particular engine/application.