ive got a 93 v6 pickup with 178 some thousand miles on it. My first problem is an oil leak coming from what i can tell either from the rear driverside corner of the intake manifold or the rear of the valve cover. It leaks out roughly a quart of oil every 500 miles and seams to be geting worse. The other problem is posibly a weak oil pump, it builds pressure fairly quickly but when it gets real hot from either mudding or pulling real steep hills in 3rd gear i drops down to about halfway between the first mark and zero and when idling it goes to almost nothing and if its just a little low on oil (1/2 a quart or less)it will rattle the valves a bit. Mabey this is just normal operating range and i sould be keeping a better watch on the oil level till i fix the leak, so let me know what you guys think. Anyhow my plan is to just pull the motor at least replace the intake valve cover and oil pan gaskets, inspect the timing belt and replace the oil pump if nessisary. Im also assuming the toyota dealership would be the best place to get all the gaskets and what not. thanks in advance

 

ouch. Sounds like there is some serious top-end seal issues... I'd sure replace the oil pump anyway, but find the source of that oil leak! Could there be a top-end oil drainage problem? Do you have nasty smokey blow-by? Any white or blue/black smoke in your exhaust? How often do you have to add oil, and how much do you add? Keep an eye on that sucker...

NOW THAT'S THINKIN WITH YOUR DIPSTICK, JIMMY!

 

I love how that guy's hair is noticeably different that his beard hair. You can tell better in the comercial than that picture.

 

Just a suggestion,but while you got 'er all ripped apart. Change the water pump as well.
I replaced my oil pump(which was bordeline a nightmare),but I figured the water pump had just as many miles on it and replaced it as well.
I got my gasket set from the dealership. Not sure what it cost me. This was about 3-4 years ago.
*tip*...their is a very small oil line,going from the pump,to the pan...becareful not to crush or kink that line. I did,but didn't notice it until everything was together and wasn't getting proper oil pressure. thus forcing me to rip it all apart to find that little problem.

 

I had a similar leak on mine. It could be coming from the cam seals on the back of the block right below the valve covers. There is a company called Mizumo automotive on the internet I bought a complete gasket/rebuild kit from and it came with an oil pump for only $260. I would highly suggest you check them out and give the lady a call there. While I had my motor out I replaced every single oil seal there was.