Prius Gen 2 2008 Transmission Malfunction with Noise

Hi Everyone, (This is my first Post)


I own a 2008 Toyota Prius and recently replaced its engine. However, after the engine swap, I encountered several issues with the transmission system:

1. Transmission Not Engaging: Both Drive (D) and Reverse (R) gears fail to engage properly. When I shift to either D or R and attempt to accelerate, the car doesn’t respond as expected.

2. Rattling Noise: A noticeable rattling noise occurs when I try to accelerate after shifting into D or R. This noise seems to originate from the transmission or engine area.

3. Parking Mode Malfunction: The Parking (P) mode is also not functioning correctly. The car can roll freely even when placed in P, which is a serious safety concern.


These issues started immediately after the engine swap, suggesting that the problem may be related to the installation process or components affected during the swap. Could you provide guidance on diagnosing and resolving these problems effectively? Any insights into common mistakes or checks specific to the Prius’s hybrid system and transmission after an engine swap would be greatly appreciated.