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TAMD 40 oil pressure drops

G

glen_adolph

Regular Contributor
My port engine runs a short while and the oil pressure drops to zero. No noise or tapping. I ran with a manual gauge with the same results. I pulled the oil cooler and checked the bypasses. Everything looks fine. Before I pull the engine, is there anything else that I am overlooking? Can I access the oil pump through the timing gear cover? Help?
:mad::confused::p
 
Oil pump is in the oil pan, on the front of the motor (its part of the #1 main bearing cap). Not sure what might be going on, but if I remember correctly a guy on here posted his engine had oil pressure drop due to dry/cracked rubber seal in the oil pickup tubing
 
The symptom is funny the way pressure drops. A dry /cracked seal on the pickup tube would explain it. Engines sat up over 10 years before I started tinkering with them.
 
Finally got back to work on boat. I was able to drop the oil pan far enough to remove pickup tube and O-ring. O-ring was hard and flat. I will try to install new O-ring tomorrow.
 
Worked on the boat today and tested the engine. Oil pressure around 40-45 psi 1800 -2000 rpm. The pressure seemed to want to drop when the engine was warm. The engine ran fine except that it would not idle. I suspect the filters. I will change the filters and retry tommorrow.
Also, I suspect the dog bone that couples the raw water pump to the engine may be causing hard starting or lack of idle. Does anyone know the correct way to install the "dogbone"?
 
When engine is warm, oil pressure will be lower (~25-35psi) at idle. However, it should not drop lower than that under any circumstances.

Dog bone only serves to turn the impeller, has nothing to do with idle or hard starting. Is the metal bone still firmly inserted into the rubber circle piece? The raw water pump shaft fits into the dogbone. It only fits in one way.
 
Good news! I figured out that the seawater pumps are not the same(Port and Starboard). It was causing the injector pump to bind or stall at idle. I switched the seawater pumps from starboard to port and problem solved! The little "dogbone" has lost the rubber ends. I think Volvo wants $70 for a new one!?! I may try to fabricate my own by epoxying some HDPE or hard rubber on the ends. I'm cheap that way.
 
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