Models: BMWs with the 4.4L turbocharged engine
When diagnosing an engine oil leak or a coolant leak on turbocharged V8 engines, it is necessary to use a borescope to identify if the source of the leak is from under the turbochargers. Using this method can avoid costly teardown labor charges to diagnose a leak. Also, this method can confirm if the turbocharger or oil pipes are leaking.
Do not remove the transmission before performing this inspection. Insert the borescope to the inside and outside of the induction pipes.