Thanks guys and gals out here on 4x4wire.com I tried that oil change to the Mobil1 Syn 0w30 and damned if it didn't all but get rid of that signature Rodeo engine noise. Granted it still makes a slight tick at startup, but after a couple of minutes, I couldn't even recognize my engine sound. Has anyone had long term experience with using this oil in our rigs? Does the benefit only get better with continued use? I've been using synthetic for a while now, but have occasionally thrown in a bottle of Syntec or Rislone. Does anyone know if I should still use Syntec or other additive from time to time for my high mileage engine?

I wouldn't think so, unless you feel you need a seal/gasket conditioner to prevent leaks. Mobil One is plenty good on its own otherwise.

Yes, the synthetic is veeerry nice. I just found a case of it at costco (5w-30) for 24 bux. ow, but not too ow.

Ive been using the mobil 1 for a good while- say a year and a half. I dont even hear the tick when I start on really cold days. I used to hear it at startup consistently. I swear that two months after I started using it the whole engine was quieter, not just the absence of any ticking.

As for additives, I just used a bottle of gw44k (I think thats what it's called, some fuel system cleaner)on an unrelated cylinder misfire problem, and even before the tank was finished I noticed better gas mileage. As for other additives... probably dont need anything. <img src="/forums/images/graemlins/cheers.gif" alt="" />

I've had nothing but problems with synthetics. Not only did mobil1 make my engine tick loudly, it caused it to knock several times. Also leaked at an unprecedented rate. I wont touch the stuff ever again.

Same thing for me. I had no leaks before trying synthetic. Soon after switching over, oil was gathering at rear main seal and also coming from valve cover gaskets. I have recently switched back to regular, but still have the leaks. Now I'm kicking myself since I will soon have to go get the seals and gaskets replaced.

94 Trooper with only 51,000 miles by the way.

Hmmm. I've been using 5W-30 Mobil One for nearly 20 years now in at least 5 vehicles, never had an engine seal leak. Never.

Also never had an engine burn much oil, well into the mid 100K mile range. I swear by the stuff...

I don't know about the 'synthetic caused an engine tick' but I know that if you have an oil leak, no matter how small, synthetic will make it worse. Synthetic is so 'slippery' that it flows easily through the smallest of spaces. A minor oil leak can become a major leak overnight with a switch to synthetic.

I'd advise against synthetic in any engine that has existing oil leaks.