Interesting problem..... Last oil change only lasted about 2000 miles before my check gauges light came on in the truck because the oil pressure would drop to zero. I used the GTX high mileage (truck had about 88000miles on it).

So my oil is going somewhere, its not smoking, theres no coolant in the oil, and altho my plugs didn't look great they were def not fouled due to burning oil. It doesn't drip oil, but i noticed a wet spot right at the bellhousing/engine. My guess was that when the oil heats up and thins out its leaking out of the rear main. 10 dollar bottle of bars stop leak and a new oil change and i haven't had any issues until.. THIS MORNING ON MY WAY TO WORK.

This time it lasted about 3000 miles before doing the same thing, oil pressure momentarily drops to zero when i come to a stop and the check gauges light comes on. Once again, it hasn't been dripping in my driveway and there is no visible leak. This time even the bellhousing/engine area seems dry as a bone. Could this be the rear main? I cant think of any other possible cause.

Also, how are the rear mains set up in the 5.2L engine? Are they the split design that can be replaced by simply dropping the pan? Im going to be putting a new clutch in the truck this week and i want to change the rear main just for laughs to see if it fixes the problem. Just need to make sure the crank doesn't need to come out.

THANKS GUYS (sorry for such a lengthy thread)!
Nick

 

If you are talking about the 5.2/5.9 there is a service bulletin for burning oil. If the truck is out of the 3/36,000 warranty as I am sure it is, the repair will cost you. The problem is that underneath the intake is a bolt in runner cover. The gasket on this cover starts to leak and sucks oil into the intake. It causes oil loss and can also cause spark knock, among other things.
I had a truck in the shop at the dealership with the same kind of problem. The customer also actually thought it was the rear main seal leaking. His problem was the rear intake gasket. From the factory, they came with a cork gasket that, over time, beings to soak in oil and starts to leak. The best bet is to pull the intake first and replace the gaskets, including the gasket for the runner cover. The new intake gaskets are a revised version and are made of silicone. Also, replace the oil pressure switch while you have the intake off. It can also cause the leak, and the oil pressure light problem and its much easier to replace with the intake off.

 

I did not see in your post that you checked the oil and found it low. If oil level is where it should be when the oil press. drops, you could have a main bearing, camshaft bearing or oil pump problem.Check oil level when this occurs.

 

its going in the intake plenum. hughes engines has a plenum reinforcement kit that is guaranteed to never blow out the gasket again, my truck was doing the same thing but not that bad.