On some vehicles, an engine oil leak from the rear of the engine at the turbocharger drain back tube could be be confused as an oil leak from behind the bell housing. The bolt holes for the drain back tube to the block are drilled through to the inside of the engine and thread sealer was not properly applied to the bolts threads, causing oil to leak past the threads. NOTE: The WSM was updated to show these bolts are a to be replaced if removed. New bolts will have thread sealer already applied.
