conventinal or synthetic????

[Gunner83]

I just got a 1997 toyota Avalon and bought it from my parents who have had it almost new and when it had 130,000 miles on it, the cam bearings took a shit and toyota replaced the top end, due to their sluge problems (do not know the real problem that caused the failure, just know that no lube=big problem) The car now has about 230,000 miles with no problems but I want to keep it that way, so I was thinking of switching to synthetic to keep this from happening again. I have looked over the deal of putting synthetic in a high milage engine and ending up with leaks, so I am at a lose... Should I keep running regular and hope for the best or shopuld I try the syn and gamble????

[MagicRat]

IMO stick with conventional oil and change it fairly often, maybe every 3000 miles.

IMO, synthetic oil is great for newer engines, where the rings seal tightly. But engines with tons of miles like yours probably have more blow-by gases (partially-burned hydrocarbons getting past the rings). This blow-by contaminates the oil and shortens its life, regardless of whether its conventional or synthetic.

So, unless you have tons of money to spend on frequent synthetic changes, just stick to the conventional stuff.

[RahX]

If you get your oil changed every 3k miles, there is no need for synthetic. They say you can go longer on it but from what I've experienced, it isn't worth the extra cost and you can't go on it long enough to recoup the amount. So, it is much more economical and just as good to use conventional oil and change it every 3k miles. If you have a car that calls for synthetic, then go for it. As for it 'causing' leaks, it doesn't cause leaks. Synthetic just tends to squeeze out of smaller holes so it is leaking out of a spot that was going to leak already. I am not at liberty to speak on the Toyota sludging problem, but I can tell you it PROBABLY is a Toyota problem. Just run some seafoam in the oil every 15-20k miles to break up the sludge.