Originally Posted by LanceA

Where do you get these? Is it a factory part or aftermarket?

Originally Posted by john talle

I have a '99 RX300 that I bought 5 months ago with 113k miles on it to do major highway driving. About 600-800 miles per week. Very quickly, I learned that, I too, had an RX300 that consumed HUGE amounts of oil, but it ran excellent! I read the forums. Called the dealer. Same message from everyone. Junk engine: $8k replacement, $3.5k for a long block. However, I was not convinced I had a bad engine. After much research and discussions with engine rebuilders, here is the long and short of it, Baseline data: '99 RX300 with 113k miles that used 1 qt of oil every 250-500 miles depending on engine load. 20 mpg. No smoke. Cyl compression varied from 145psi per cyl to 180psi per cyl. Again, it ran good. THE FIX: I ran 3 cans of Mopar Combustion Chamber Cleaner,MCCC,($8/can) in the intake with 500 miles between cans. Drove the car hard in between cans of cleaner. Once I ran the cleaner through, I took the valve covers off and replaced them with the updated ones at a cost of $400. No sludge. Cleaned out the intake (it was covered in oil) and omitted the PCV-intake hose and ran a hose to an external cone filter. Checked compression: 220psi per cylinder. Put in new plugs. I have 127k miles on it now and it has NOT used oil for the last 7000 miles. As it turns out, sticking piston rings caused excessive blow by which causes crankcase pressure which forces oil through the PCV and into the intake, which runs down into the cylinders and burns it through the combustion chamber. My research indicated that the MCCC is the best upper cylinder cleaner on the market. Local Chrysler dealer said the Ford dealer buys it from them by the case. The fix worked for me. No guarantees, but it makes sense. I did it all for $500. I'm much happier with my RX now.