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Today I changed my antifreeze. I pull the block plugs to get all the old antifreeze out. Not thinking or thinking of something else I pulled the little plug on the block up by the oil pan inbetween the oil filter and motor mount. Nothing came out? I looked at the plug closer and it had engine oil on it. I then went duh, there's the plug I want back by the trans to drain the antifreeze. My question is, what is this little plug for? Is it a pressure line or a drain back to the oil pan hole?
Ian, I'll get a picture today. Tim, no, that's not the plug because I have my bypass running to that port. Its a little tiny square head plug that a 8mm open socket on it was loose. I couldn't find my 7mm so I took it off with my 8mm.
Glenn is it on the boss that comes out from the block closer to where the trans mounts? If so that is another oil pressure port. not sure what its purpose is
This is laying on the ground looking up. Oil pan on top, oil filter head on left (I used this to run oil to my cooler is why you can see past where there is usually a filter) on the right is the motor mount and of course the freeze plug below it.
Tim, I didn't see the one your refering to, I'll have to look again.
Why would they drill the oil passage ways? Is this something done during a rebuild? Interesting!
He is talking about when they drill the oil port in the block to the bearings from the factory when they are producing the block. That plug should just be an oil pressure port like shown in Jim's post above. It's hard to see in that pic, but it's there.
probably could put a gauge there along with other places in the block, but most people put the gauge sender in the HPOP rez, in place of the fill plug.
As far as I know there are only 2 oil pressure ports on the driver's side: One as shown in the pics and the other all the way upfront near the front cover.
There are, however, several plugs (I think several) on the side that would work as drains since they are open to the pan. And I believe it's suggested looking in one of these to see if you have PMR in the newer trucks.