After I paid about 600.00 to have the rear engine seal replaced. (Transmissions has to be pulled) I now use Snythetic oil. Later, I changed the front seal and both camshaft seals when I changed the timming belt. It did not cost much, due to these seals being exposed and right out front when the timming belt is replaced.
I would strongly suggest to anyone changing the the timming belt, to also change the front crankshaft seal, and both camshaft seals. I watched the guy do mine and it did not take him even 10 to 15 minutes to change all three seals when doing the timming belt.

Pilot

91 LS400
01 RX300

 

Mine is a 91 with 73000 miles on it. I was thinking if it leaks as much as it does right now (not much), it shouldn't do any harm to the engine. Am I right or it does in fact do harm to engine? Also, does the leak get bigger with time, or it stays the same? Also, regarding the part that fails and subsequently causes the leak, is this part something that will need replacement anyway (just like spark plugs do), or is it never supposed to fail? In other words, have we had bad luck with it, or is it something that everyone will do at some point (like a spark plug replacement).

Thank you in advance.

 

Its just a an oil seal. It will not harm anything other than leak oil.
It may not even show up on the dip stick as being low, but you need to checkyour oil level very few weeks just in case.

Pilot