Final answer:
When oil is leaking from the crankshaft rear main bearing seal on an engine, there could be a couple of possible causes. It could be due to a faulty oil seal or a malfunctioning PCV system. Both Tech A and Tech B could be correct in this situation.
Step-by-step explanation:
When oil is leaking from the crankshaft rear main bearing seal on an engine, there could be a couple of possible causes. Tech A suggests that a faulty oil seal could be the problem. This is a common issue because the rear main bearing seal can wear out over time, causing oil leaks. Tech B proposes that the PCV (Positive Crankcase Ventilation) system may not be functioning properly. The PCV system helps to regulate the pressure and flow of gases in the engine, including oil vapors. If the PCV system is not working correctly, it can lead to excessive pressure and oil leaks. In this case, both Tech A and Tech B could be correct, as either a faulty oil seal or a malfunctioning PCV system can result in oil leakage.