I have a 93 vg30e engine. I wanted to know the flushing procedures because I found a bit of water in my coolant resorvoir. I dont quite know where the drain plug is on the engine, but I do know where it is on the radiator. I have plain water in the system, but its really hot down here, so thats not good. I flushed the radiator before, but not the engine.

 

I recently flushed my engine and I used the drain bolt located on the lower front of the engine. Look for it at the base of the oil dipstick. I was unable to locate the other drain bolt, but I did fine with this one.

 

I also just recently flushed my system but i just unplugged all the hoses at first from the radiator then flushed that out.... then i hooked up the bottem radiator hose and left the top 1 off pointing away from the car.....i started the car while i had cold water running through the radiator and the top hose was still unplugged spewing hot orange water everywhere.....i did this for about 20 mintues...i also unplugged the heater hoses and tried back flushing through my heatercore to get some of that orange crapy sludge out of there... thats why i think i have heat issues.. I then just filled it back up with antifreeze and water....

 

This seems like it may be easier than what I did... I just did what the manual said.