RS4 turbo

[dwlon]

My mechanic says I’ve got an oil leak from one turbo which needs to be fixed, along with another leak from one of the intercoolers. But now blue smoke is also coming from one of the exhaust pipe outlets at intervals, which is worrying.

There is also a high-pitched whining noise which is most apparent when accelerating between 40 and 90 mph, plus I detect less power boost when accelerating.

Are these indications of turbo failure? If so should I get the turbos replaced or refurbished? The current units were only fitted 30,000 miles ago.

I recently had an oil leak fixed, the rocker cover gaskets and oil breather pipe needed replacing. Could this have exposed problems with the oil supply to the turbo?

Any insights or advice welcome.

Thanks

[Adam L]

If you've got an oil leak from the intercooler pipe it means you've got an air leak which isn't good news. If that's been like that for a considerable amount of time that'll be the reason one of the turbo's is on its last legs. When you have an air leak on a turbocharged car the lost pressure is compensated for by the turbo overspinning itself to make up the extra boost. The turbo will most likely have worn the thrust bearing through (in and out play in the shaft assembly), which you'll be leaking oil down the exhaust and inlet from. Also, when a turbo has thrust play in it the wheels get forced into the outer casings and the tip height (pofile) of the wheel is destroyed giving you a loss in boost pressure.

[dwlon]

Thanks for the insight. I had the vehicle examined by a specialist who said both units had to be removed and reconditioned and the forced induction system overhauled. I agreed, and have now discovered that the previous owner of the car had had stage 1 K04s fitted which were not supported by a commensurate remap of the ECU (?). The system was dysfunctional and the turbos failed, with parts worn out, oil leaking and boost pressure massively down. The ECU now requires a custom map to support the performance turbos taking the power output (so I'm told) to 460bhp.