Disregard.

6 VOLTS/POS. GRD. NW INDIANA

I’ll suggest removing the other head and checking for irregularities around the gasket and machined surfaces.  If you are not getting water in the oil but instead are getting oil into the coolant, this leads me to believe that you have a leak only related to the oil pressure and not the other way around.  Examining the other head gasket may help to identify this.  If no luck there, then a crack in the block or the heads comes to mind.  With the cylinder head off the engine, try pressurizing the oil galley in the head and check for a crack there.  Those cracks in the blocks can be found with the block out of the vehicle and with them fully disassembled by pressuring the oil galleries and using soapy water.  Those internal cracks are difficult to find on an assembled engine and especially when installed in the vehicle.

Lorena, Texas (South of Waco)

I have had 2 blocks (from the southern us that had thin cylinders and required sleeves,this was caused by airiated water as well no antifreeze.this came from the machinest who bored the block.the other clue was front cover was eaten threw on right entrance to block.. pictures show #4 is cleaner than 1 2 3 
I think the 1st place to look is if the  #4 was bored oil will show up if wall  is  thin. pressure in rad would show if upper cycle was cracked. in my case the bore cut showed a hole only at the lower part about 1in up from the end of bore this was on #8as well. hope i am wrong

Were you describing engine re-builder problems on this tuck about a year ago on FTE?

Anyways...

Can you show (photo if possible) of CASTING ID for the block and the cyl heads? What gasket vendor was used on assembly?

Was the block squared and the heads trued during rebuild?

____________________________

Oil pressure will decrease as the engine gets warmed up.  If 60psi is cold and 20psi is the lowest it gets at idle and normal operating temperature, then it is not necessarily an indication of anything being wrong.  On the other hand, 60psi at hot idle would be excessive, indicating some problem.


Lawrenceville, GA

Well a long overdue update. Life has gotten in the way but If anyone is still interested here we go. I ordered a new gasket for the right side. Went to put the head back on last fall, got down to the last torque and I spun out the threads. CRAP!!!!!!! We were in the middle of a move and winter barring down on us so I took it to a local shop. Finally got it back this sprig. Finished putting it back together and crossed my fingers. Long story short......I am still getting oil in the coolant.  Truck runs great. I did notice something strange. As I was flushing the the block (for about the 10th time) my oil pressure was great. I then but the Radiator cap on and the pressure slowing went lower as the engine reached operating temp.  From near 60 psi to 20 psi.. Could this be a clue? Maybe it is the other head gasket? What'ch u'all think?

What was the oil pressure when running?  Do you plan on pulling the left side head?

Lorena, Texas (South of Waco)

It does look like the gasket was not clamped sufficiently between 2, 3, and 4.  The dark spots are the clue.  It looks like it's about 1 1/2" long between 3 and 4 and maybe 1" between 2 and 3.  The relatively clean #1 piston could be a sign that coolant is getting into that cylinder.  It does look like coolant may be making it's way from the passage just above to that cylinder and possibly to the oil drain into the valley.

The block does not look like it had been surfaced.  Clean all of the gasket material off and then check the head and block surfaces with a straight edge




Lawrenceville, GA

Pulled the head off of the right side of the engine today hoping to find an obvious explanation of why I might be getting small amounts of oil in my coolant. I based this decision on the lower compression values in cylinders 2-3-4 that I posted earlier. Unfortunately nothing stood out to me. I took a few pictures. Do you guys see anything that might be suspect? Is it common for the tops of the pistons and heads to be blackened already with less than 50 miles of road time? Other than the lower compression and oil in the coolant the truck has ran great since the rebuild. My rebuilder guy has not had any explanations to this point but I am going to share the pictures with him also. Otherwise I will just put it back together and hope for the best.

according to fel pro all y blocks from 55 up take the same gaskets.i remember gasket sets years ago that had 239 to 312 for 55 up listed on the box.ever the 54 256 takes the later head gasgets.only the 54 239 is different on cars at any rate trucks i dont know as some were suppose to be different