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671 TI Coolant in oil

bruce_macgregor

New member
"Hi, I just found about 1 Gal

"Hi, I just found about 1 Gal of coolant in my L.O sump after being laid up (Boat) for the winter.
Any ideas as to where to look for leaks before n pulling the head and having it pressure tested??
The engine ran fine last year.
Stewart & Stevenson 6-71 TI, 415 HP
Thank You
Bruce Macgregor"
 
SOUNDS LIKE A INJECTOR TUBE LE

SOUNDS LIKE A INJECTOR TUBE LEAKING UNDER VALVE COVER OR HEAD GSKT. REMOVE THEMOSTAT AND PRESSURE TEST ENGINE.
 
"could be a number of things,

"could be a number of things, pressurize engine cooling system, pull inspection covers from side of block to see if water is falling into a cylinder to eliminate a cracked head or injector tube, also check air box drain tube or collection can for water"
 
"Follow up! Pressure tested co

"Follow up! Pressure tested cooling system to 16 # slowly dropped of to 3# in about 45 min.
Pulled head and found pressure ring on #2 cylinder blown out at about 2 oclock.
near enough to overheat a water seal grommet near it, which is next to the dummy cam oil gallery. I assume the coolant leaked from the grommet into the oil gallery.
Now I need to learn why it failed !
1, Liner hight above deck?
2, Head bolt bottomming out?
3, Head is off for a pressure test & inspection to eliminate cracks, Etc.
Any Advice or Knowledge about any of this is appreciated
Bruce Macgregor"
 
"bruce, could be that the head

"bruce, could be that the head was not installed correctly or the liner height is not right.The liner height can not vary much between ajacent cylinders, it tells you in the service manuel."
 
"Hi, We are in the process of

"Hi, We are in the process of checking liner height, found it hard to measure with a dial indicator because of moving the mag mount from cyl. to cyl. Hours are ~1700, Cylinders look like new.
The head is still @ the machine shop due to long weekend,
Bruce MacGregor"
 
"Bruce you need a depth mic al

"Bruce you need a depth mic also there is a special tool that gose across the top of the liner when checking height, look in the service manuel it explains how to do it,good luck"
 
"liner height measures .050 to

"liner height measures .050 to .052 below deck on all cylinders using dial indicator.I dont have a manual that tells what it should be, But that must be close. The fire ring that failed delaminated then blew through.
No word on head yet!
Bruce MacGregor"
 
"You're right, it's cl

"You're right, it's close. Manual calls for .045-.050, with a maximum of .002 difference between adjacent cylinders."
 
"Hi, Here's the follow up.

"Hi, Here's the follow up.
Head had cracks in 2 places, I replaced it with a new head "Made In China". It looked great & fit perfect. There was also fire ring gasket delaminated on one side on Cyl #2.
Engine is back up & running.
Thank you, to all who took the time to answer my questions.
Bruce MacGregor"
 
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