I knew you were kidding, cause nobody knows what's in MMO. I quess that's why they call it Mystery Oil . For some reason, the gasket seeped coolant up near the very front, right edge of the block near the t-stat housing. The mechanic said there was nothing wrong with the head or block, the gasket just didn't get a proper seal when it was assembled and prematurely failed. I had heard at one time that around 92 Cummins did have a run of faulty head gaskets. So I could have gotten one with a bad gasket or the previous owner overheated the engine at some point. But all is well and torquey now.

 

i burn my old engine oil. so far, so good.

 

That area is a pretty common place to leak coolant. I have replaced several head gaskets on these trucks, and the majority of them leaked right there on the right front corner. My own truck seems to have started too. If you look at the gasket, there is a coolant passage right there in the corner, with not much of a sealing bead around it.

 

This is what I do with the waste oil from my CTD https://www.dieseltruckresource.com/...sort/1/cat/500

 

that ain't a bad way to go either

 

What do you guys think about Lucas upper end addative. I either run lucas or marvel no problems