You switched at 115k? how many miles have you used synthetic for? It took me about 6 to 8k miles before I saw it leak.

 

only about 4 months

 

If you don't want to go syn, get the Mobil 1 Clean 5K...a good conv, IMO...and $11 for 5 qts.

 

Mobil Clean 5000 is a synthetic blend, right? I use that in my mowers and that stff is great for being so cheap! It is cheaper than AutoZone convential!

 

My valve covers were the first to start leaking, then my rear main and front seal soon followed. I hope this doesn't happen to you but I honestly think its right around the corner. Seeing as how you just switched. I have since switched from royal purple to straight conventional oil. Keep a close eye on those leaks.

 

Just an update, the plenum gasket was the problem. I replaced it with a Hughes kit, 1000 miles later no leaking or burning oil.

 

well, when i switched, i was changin my bent rod, so i got new valve cover gaskets and oil pan gasket, dont think i changed rear seal tho

 

Glad to hear you got your plenum fixed.

On another note I switched over to amsoil with about a 100,000 miles on the motor and have not have not leaked a drop in the 20,000 miles I've put on it since. It's kind of expensive but it's totally worth it. They started using it in the vans where I use to work (Because you only have to change it every 25,000 miles, although I personally never go past 10,000) and some of those motors had 180,000 miles on them so we figured it'd leak right through the seals. No problems though. Really great stuff

 

just got my 98 dodge 1500 5.9 back from my sis not running at moment but was told they had to fill it with oil every 100 miles.....plenum gasket?

 

I would think that a plenum sucking that much oil would be creating a hallacious smoke screen behind you. Sounds more like a bad oil leak.