donmaccapecod

I own a 2009 RX350 and have the diesel sound until the engine warms up. I have looked in the internet sites and found the following explanations from various sources: PISTON SLAP-some say the shorter height of modern pistons are the cause and others say the pistons are oval shaped for a reason and after heatup fit the cylinder better. HYDRAULIC LIFTERS- heatup give better oil flow. INJECTORS-Fuel injectors make noise until warm. CAM SHAFT ASSEMBLY-There is a TSB relative to the cam shaft assemly. Heatup causes the parts to expand and quiet down. TIMING CHAIN- Maybe it hits the surrounding cover ? Take your pick from the internet experts. I pick the hydraulic lifters. donmaccapecod