I've got a EJ25 DOHC motor that is burning on the order of 1 quart every 100-150 miles. When driving it you do not really notice any smoke out the back, until you coast down a hill. If you are up to speed (40-50 mph) and you coast down a long or hill for something like 1/8 mile, and get back on the gas a big cloud of smoke erupts from the tailpipe. Now everything I know tells me that this is valve guide seals, but I wanted some other input before I go tearing apart the motor.
I have since done a compression test both dry and wet and found no problems. AND I've since replaced the PCV valve, with no change in the burning rate. THIS IS IMPORTANT.
So, I decided it must be a mix-up in the valve guide seals by the machine shop that rebuilt the heads for the person I bought the engine from, and started today to swap on my known good heads.
Here is the good stuff:
I pulled the intake manifold off to find oil running down the inside of the intake runners, and oil pooled up on the intake valves!!! Now I'm baffled. I replaced the PCV valve with a brand new one from the dealer, all the hoses were clear, and everything is hooked up correctly. What could be the problem? I did notice that as I was taking the intake tube off with the breather hoses for the valve covers, that what seemed like water ran out of the one. Could there be something wrong in that breather mechanism of the valve cover that is letting the oil through?
Oh, and thanks for all the input.