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.
My 350 Sounds Like A Diesel!
in 04 - 09 Lexus RX330 / RX350 / RX400h
Posted
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