The correct operation of the lubrication and sealing systems relies not only on the components inside the turbo, but also on many systems on the engine or vehicle.

The turbo has simple requirements: clean, filtered oil of the correct type specified for the engine, clean, filtered air and clean exhaust gas. None of these are exclusive, they rely on each other.

The job of the oil is primarily to lubricate all the internal moving parts of both the engine and the turbo, but it also carries any debris or wear particles from the engine, which should be removed by the filter. If oil and filter change intervals have not been respected on the engine, then the concentration of contaminants being carried around by the oil can reach excessive levels and under these conditions, it can be expected that damage will occur to the bearing system of the high-speed turbocharger.

An excessive concentration of fine particles, which may be typically carbon particles from the combustion process, turns the lubricant into a very effective polishing or lapping medium, which will polish and erode the material of the bearings, increasing critical clearances until the oil can no longer effectively control the complex motion of the shaft and wheels.

This leads to excessive shaft motion which is often accompanied by a sharp increase in noise level and a reduction in performance. The excessive shaft motion can cause metal to metal contact within the bearings, rubbing of the shaft on the piston rings, causing rapid wear. This is often followed by oil leaking from the turbine or compressor end or both and then total failure.

If you want to learn more about oil drain system restrictions, change in the pressure balance and dry start-up and oil leakage stay tuned for the upcoming Level 4 training on Installer Connect starting with July 15th, 2020.