Replacing a turbo

RECONDITIONED WASTEGATE turbos are available, but not the variable vane type. Variable vane units require to be calibrated with their control unit, an extremely precise job requiring sophisticated equipment. I understand suppliers usually require the old variable vane turbo, not for remanufacture, but for scrapping to keep it out of the reconditioning market. Aim for an OEM (original equipment manufacturer) unit and be wary of fakes. Only the exact type for the engine should be fitted.

Never attempt DIY service. Parts are difficult to obtain, special tools are needed and the assembly needs to be precisely balanced at speed, and maximum speed and boost needs to be set under test.

DIY REPLACEMENT OF WASTEGATE TURBOS: Before fitting a replacement turbo it’s essential to establish why the original failed. Ignoring existing oil supply problems, or just failing to prime the turbo’s oil system before starting the engine for the first time, can quickly damage the precision shaft bearings of the replacement. Ensure oil inlet and outlet pipes to the turbo are clean and clear internally, and are refitted with new seals or gaskets. Ensure any debris from the previous failure is removed from the engine. Use new engine oil and a filter of the correct specification and quality, and continue doing so at service intervals. Confirm air intake and exhaust manifolds and oil feed and return pipes are clean internally.

The new turbo should fit comfortably to the exhaust manifold and pipe without straining any part into alignment. Prime the oil inlet of the new turbo with new engine oil to ensure lubrication immediately on start up, then idle the engine for at least half a minute, checking for leakage from oil, exhaust and air connections. Boost pressure will need to be set by a garage, unless a pressure gauge can be connected.