Greetings! I added the air filter and oil separator kit on my 1984 300d. It works fine.It draws outside air which can't hurt. Gets rid of the OEM air cleaner, oil separator etc. which makes me happy.It seems to require oiling and frequent checking.No problem there. Yes,the turbo spools up quickly with no lag.The turbo intake stays very clean.I think I'll keep it.
The last couple of posts are interesting in that they refer to blowback gases and pressure changes inside the valve cover. After my installation I noticed an oily area around the elbow connection to the valve cover.Gases were escaping.I removed the 1/2" "kit" hose,from the elbow to the new oil separator and replaced it with four feet of 3/4" heater hose.Since then no more oily signs of gas escaping under pressure.
What do you think would be the long term effects of excessive back pressure inside the valve cover? Not enough pressure to stall the motor.Would it damage the head gasket?Thanks