Why turbos start smoking?

Turbochargers can start smoking due to several reasons:

Oil Leakage: If the seals or gaskets within the turbocharger wear out or become damaged, oil can leak into the hot exhaust housing. This oil can then burn off, producing white or blue smoke.

Oil Supply Issues: If the turbocharger is not receiving an adequate supply of oil, it can cause the bearings and other internal components to overheat and start failing. This can lead to oil leaks and smoke production.

Damaged Compressor Wheel: Damage to the compressor wheel, such as cracks or nicks, can affect its ability to compress air efficiently. This can cause higher temperatures and excessive pressure, leading to oil leaks and smoke.

Failed Bearing(s): Worn or damaged bearings within the turbocharger can cause excessive play or vibration, resulting in oil leaks and smoking.

Excess Exhaust Pressure: If the turbocharger is subjected to excessive exhaust pressure due to a clogged or restricted exhaust system, it can cause the turbine wheel to overheat, potentially leading to oil leakage and smoke.

Engine Problems: In some cases, smoking from a turbocharger can also indicate underlying engine issues, such as piston ring wear or blow-by, which can allow oil to enter the exhaust system.

It's important to note that smoking from a turbocharger is usually a symptom of an underlying problem and should be investigated by a qualified mechanic. Ignoring the issue and continuing to drive with a smoking turbocharger can cause further damage to the turbocharger and potentially other engine components.