Turbocharger LUBRICATION Maintenance

TURBOCHARGERS AT RISK DUE TO LACK OF LUBRICATION

Turbochargers are durable and very tough equipment. A turbocharger is a technically complex component and delivers top performance even under the most extreme conditions: shaft speeds of over 300,000 rpm, exhaust gas temperatures of over 1000 ° C, and boost pressures of over 2.5 bar are completely normal values. And a modern turbocharger must reliably withstand these stresses over many thousands of kilometers and years. But life with a turbocharger hangs by a thread: the thin oil supply line! Although it is usually only a few millimeters in diameter, it is essential. A bottleneck can have devastating consequences here.

TURBO INFARCTION RISK

Hot Spot - The oil supply line runs directly over the hot exhaust side.

DEPOSITS

Aging and the effects of heat cause carbon deposits to form in the inlet and reduce the throughput to the turbocharger. At some point, this minimal lubrication is no longer sufficient - the bearings start to seize up.

What to do: Always change the turbocharger with the line, replace missing or loosened insulation.

KINKS

Flexible oil lines in particular kink sooner or later. When having plastic deformation, it is impossible to restore to the original shape. Here too, there are supply bottlenecks.

What to do: it is essential to replace bent or kinked lines.

STOP! Do not use sealant. The seal provided for this is entirely sufficient.

SEALS

Liquid sealants are an absolute no-go for turbo repairs. They can clog the inlet and block the fine oil holes in the bearing housing. If you use such means during installation, you are not completely sealed!

What to do: only use the enclosed seals - and nothing else.

PRESSURE DROP IS FATAL TO TURBOCHARGERS

Deposits clog the suction strainer of the oil pump.

Like the crankshaft, pistons, hydraulic valve lifters, etc., the turbocharger requires an absolute oil pressure. The charger only works correctly when the engine oil is under pressure. A lubricating film is created between the shaft and the plain bearings, on which the shaft virtually "floats". There is almost no wear and tear because the two bearing partners do not touch. Disturbances in the oil supply are first noticeable in the turbocharger because it is the weakest link in the oil circuit. Other bearing points are less loaded and, above all, have larger dimensions. If the oil pressure fails under full load, it only takes a fraction of a second, and the turbocharger is over. The most common causes are defective oil pumps and blocked control valves that adjust the oil pressure depending on the speed.

What to do: check the oil pressure and the amount of oil delivered; control the pressure even under different load conditions.

A "SICK" ENVIRONMENT HARMS THE "HEALTHIEST" TURBO

Malefactor: When the particle filter is full, the turbo has a hard time

A lack of lubrication can also arise despite a free oil supply line and perfect oil quality. Namely when there are malfunctions in the engine environment of the turbo: for example, due to a clogged diesel particle filter (DPF). Because the saturated DPF develops such a high back pressure, the exhaust gases can no longer flow unhindered from the engine into the DPF. Consequently, they look for the path of least resistance - and that is through the turbine side of the turbocharger back into the oil pan. In doing so, they pass the radial bearing on the turbine side, displacing the vital oil film. This creates insufficient lubrication, the bearing partners touch, and the shaft begins to seize and, ultimately, jams.

What to do: Always check the particle filter's loading status and regenerate or replace it if necessary

DANGEROUS FOR THE TURBOCHARGER: BAD OIL

The oil quality plays an enormous role nowadays. Special additives are required, especially in modern diesel engines. Without these additives, expensive engine damage can occur. In addition, cleaning additives are added to the oil. These prevent oil carbon and other residues from sticking or loosen them. If savings are made here, the turbocharger suffers first. Inferior or old oil can lead to increased carbon build-up. These residues then act like abrasives on the radial bearings of the turbocharger - wear increases too.

What to do: Always make the customer aware of the importance of high-quality motor oil.

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