oil pressure dropping
 

98 blazer 4WD 122,000 miles
about a month ago my intake gasket was leaking, so i get that replaced even though i've heard from several people that once u do that, things in the bottom start to go wrong. Yesterday I'm driving home and my oil pressure drops to about 5-10psi. Immediately pulled over and turned it off and later drove it home seeing as i was less than a mile away. Replaced the sending unit thinking that might be the problem. Cranked it up, oil pressure is around 30. Drove it long enough for it to get up to about 200 and i lose oil pressure. Tried again this morning, same thing happened. Gets hot, then loses pressure. Out of curiousity, I changed the oil in it and there was a lot of metal on the end of the plug and the oil has a grey, metallic tint to it. So am I completely screwed?? Oh and the engine isn't really making any bad sounds, knocking, ticking etc. so I dont think I've spun a bearing...... yet. Any ideas??

Sounds like the bearings have been trashed... Sad to say. I too would not suspect that you have spun a bearing, just that they have been worn down too much.

The problem that often occurs when an intake manifold leaks is that it leaks into the oil. Water is not a good lubricant given the temperature, pressure, and materials present in the rotating assembly of an engine. As the water displaces the oil, it will wipe out the bearings.

You could try to run a thicker oil to see if it will maintain pressure once warmed up, but you will only be fending off the inevitable. You will need a rebuild soon.

i'm not even gonna try a thicker oil as putting off a bottom end rebuild could cause more bearings to go bad resulting in having to take out the entire motor... oh joy. Any thoughts on which bearings are gone?

You are going to have fun if you are going to attempt a bottom end rebuild without taking the motor out...

Does it really matter which one is bad? You are likely looking at main bearings and when you do that, it would be foolish to not replace the rod bearings.