600 series isx oil leak

[Waterloo]

Sounds like the CM-870 if there is no crank case pressure filter box and a straight hose to the ground...

The UV oil dye worked extremely well to track down my front cover leak, it took around a dozen of those little bottles, NAPA sells them in half dozen boxes. Wash the motor down, I used hot water, Dawn dishwashing detergent and a few ounces of gasoline and a rag. Drove the truck for around 50 or so miles, got her in a dark garage and used the black light and yellow glasses, the leak was easy to discover, took all of a few seconds to track it down.

The rear of the motor could be the rear structure is leaking or cracked. There is an oil galley that runs from the passenger side of the block through that structure back to the block/pan. If there was any transmission work, like a new clutch, many shops skip the installation of the new structure gasket, which 9 times out of 10 leads to a rear oil leak.

Another place to check... There are two plates on the back of the head that cover the rear end of the cam shafts, I wonder if one of those is not loose? Just need to get your hand back there, each plate is held in place with two 10 or 13mm bolts. Should be easy to check.

And that white steam and pressure, sounds like a liner cut loose, not what you want to hear... Go to NAPA and pick up their block test kit, https://www.napaonline.com/en/p/BK_7001006 Get the engine up to operating temps, and run the test, you will know if there is exhaust gas in the coolant in a matter of minutes. I am surprised that the shop did not run this test... Really not.

I wonder what the oil cooler is doing too... Many shops totally skip replacing that, it is located internally on the passenger side of the block behind the EGR cooler. If it is the original, that needs to be replaced.

And that cracked valve cover? WOW, those lids are tough as nails, there is something going on with that head to crack that valve cover unless the parts monkey used a 1/2" rattle gun to install. I just ran an overhead on mine and used the 1/4" Milwaukee M12 ratchet to set mine as it does not over torque the bolts. Almost sounds like the head is expanding to crack the center bolts on that cover. Something seriously wrong and would not be the first time. Many of us have been there, myself included. I am more of a mechanic now than a truck driver.