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John Deere Powertech 6068 low hour engine, coolant in oil.

Curtis T

Member
Joined
Jan 27, 2022
Messages
7
Location
Winnipeg,Canada
Have a 6068 has been getting coolant in the oil, pressure tested the oil cooler it was fine, pressure tested the cooling system very slow to drop pressure. Then pulled oil pan to pressure test and get a visual if the liners are leaking, found the coolant to be leaking out from the oil pump pick up tube, likely coming thru the oil pump outlet tube, thinking maybe an issue with the oil cooler housing, casting flaw, or wonder if its possible that a coolant passage is leaking into a head oil supply passage thru a head gasket leak that isn't affecting the combustion chamber?
Just wondering if anyone has come across this one before, might cut down some time on site.
Thanks in advance for input.
 

mg2361

Senior Member
Joined
Jul 5, 2016
Messages
5,390
Location
Pennsylvania
Occupation
Equipment Mechanic
Please post the complete engine serial number.

Those engines, depending on the serial, had oil cooler housing issues where the two O-rings that seal to the cooler had rough machining in their grooves. Is the oil cooler housing cast aluminum or cast iron?
 

Curtis T

Member
Joined
Jan 27, 2022
Messages
7
Location
Winnipeg,Canada
Yes it had an aluminum housing, I will take it off and have a closer look for machining defects or cracks. Will update later, thanks for the tip
 

MasseyAgco

New Member
Joined
May 4, 2024
Messages
1
Location
South Dakota
I have this same engine in a Patriot Sprayer doing exactly the same thing. Were the O-rings difficult to change on the cooler? I am guessing one large o-ring on top side and same on the bottom?IMG_3241.jpeg
 
Last edited:

Diesel Dave

Senior Member
Joined
Sep 29, 2022
Messages
1,220
Location
Ontario Canada
I have this same engine in a Patriot Sprayer doing exactly the same thing. Were the O-rings difficult to change on the cooler? I am guessing one large o-ring on top side and same on the bottom?
@MasseyAgco , I don’t believe you have the same style oil cooler as the original poster.
Orings #17 and #18 are the most critical when dealing with oil / coolant cross contamination. See screenshot below.
.
1714864444807.jpeg
 
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