I just picked up a really well maintained Lexus RX300 with the standard issue 3.0L Toyota engine. I've been reading a lot and see that these engines have been prone to sludging issues (or gelling as some call it). Apparently it has to do with an inadequate PCV system design: http://www.toyoland.com/sludge.html
While mine hasn't exhibited any of the symptoms (yet) I was wondering if there's any proactive measures one could take to minimize the risk. I understand running full synthetic virtually eliminates the risk but my concern is if the engine has some sludge in it won't going to full synthetic with its high detergent properties possibly loosen the sludge and block oil passages, oil pickup tube, etc? On my older, normally aspirated engines I used to run a qurt of kerosene thru it for a 15 minute parked idle prior to changing oil and filter to "clean" the inside of the engine. I hesitate to do that with newer engines though.
Do you think one solution would be to run a valve cover breather filter in lieu of the oil fill cap? What effect (good or bad) could that have? Would it screw up any electronically monitored signals (MAP, etc)?
Thanks for any thoughts.