Toyota Starts Testing Troubled V6 Engines with a Hammer (2 Photos)

The saga surrounding these engines has dragged on for over two years. As part of a recall campaign impacting Toyota and Lexus SUVs equipped with the 3.5-liter twin-turbo V35A engine, Toyota has rolled out an unusual official diagnostic procedure. Service technicians are instructed to use a plastic hammer to check the crankshaft's condition and determine if a full engine replacement is necessary.





The method relies on measuring resonant frequency. Before running the test, technicians change the engine oil, warm the engine up to operating temperature, remove the drive belts, and lock the crankshaft in a specific position. An accelerometer is then attached to the crankshaft bolt and connected to specialized diagnostic software.

The technician delivers a controlled tap with a plastic hammer to the crankshaft pulley at the 3 o'clock position. A computer analyzes the impulse parameters, monitoring impact force and rejecting improper attempts. Once three valid readings are captured, the data is sent to Toyota's cloud platform, which assesses crankshaft bearing wear and automatically determines whether the engine needs to be replaced or is cleared for use.



The massive recall stems from potential metal shavings left behind during factory machining. Debris in the lubrication system leads to accelerated bearing wear, knocking noises, and potential engine seizure. This newly developed acoustic-vibration method allows dealers to identify damaged engines without time-consuming and costly tear-downs.