no oil pressure

[offshore24]

Ran the boat easy all day, maybe 3500 RPM's all day. When coming in I noticed maybe 5 lbs oil pressure. If I revved it maybe 8 lbs. No knocking, banging, clunking, just valves tapping. Pull the pan hoping to find the oil pump pickup off, rebuilt the motor 2 seasons ago and put a new pump in and welded the pick up on. It's still on. Pull #2 main bearing looks OK. Pull #1 rod cap, bearing looks OK. Any ideas as to where to go from here. Engine has maybe 40 - 50 hours.

 

[PatriYacht]

More info would help. What was your oil temp when you slowed down to idle?
Are you sure the oil pressure gauge is accurate? Has it ever been checked against a mechanical gauge? Have you opened up the oil filter and looked for bearing material? It sounds like the engine is out of the boat and the oil pan is off. At this point, I would take all of the caps off and look at all of the bearings. I would also check the cam and lifters if it is already torn down this far.

 

[OldSchool]

I think that I would have ruled out the gauge before pulling the engine!!!

Hope it all works out for you!

 

[Airpacker]

Relief on pump stuck is my guess

 

[Chris]

Run it with a drill is a good idea too- you can tell by the torque needed. Also check for bllock plug problems. Where is your pressure sender? I don't care for them anywhere but in the block.

 

[jeffswav]

Ran the boat easy all day, maybe 3500 RPM's all day. When coming in I noticed maybe 5 lbs oil pressure. If I revved it maybe 8 lbs. No knocking, banging, clunking, just valves tapping. Pull the pan hoping to find the oil pump pickup off, rebuilt the motor 2 seasons ago and put a new pump in and welded the pick up on. It's still on. Pull #2 main bearing looks OK. Pull #1 rod cap, bearing looks OK. Any ideas as to where to go from here. Engine has maybe 40 - 50 hours.

If you want good answers you will need to give a little more detail. Is the engine modified to make more power than stock? Did you upgrade the oiling system, fittings, lines and oil cooler? Do you have the correct bypass valves installed? How did the oil look? If the engine is modified do you have stock exhaust? These are all things I did not know about and caused me a lot of problems.

 

[offshore24]

Trying to answer all your questions. Engine is out, not the guage plus valves where tapping like crazy( definitely no oil up top), sender in block, mild upgrades(cam,carb,intake,exhaust) oil temp around 220, no metal in oil. Keep in mind the engine has been the same for several years and rebuilt 2 years ago, so it's run 2 seasons since the rebuild with no trouble. If I use a drill to pump the oil with all components still in the block will oil get to the top without the engine turning.

 

[Chris]

If you use an engine pre-oiler. It blocks the oil gallery in the back where the distributor goes. If it's not stiff, you probably have a bypass issue. Pull the plugs and rotate the engine to feed the lifters.

You can do the same thing with the pump off and in a bucket of oil- to test the pump bypass. Get a helper or it's messy. Or you can pull the pump endplate and see if the plunger is open.

Bottom line- something changed. And if it isn't bearing clearance, it's in the oiling circuit. I'm going to assume that you don't have anything external that could be causing issues, like an oil thermostat.

 

[offshore24]

correct, no thermostat. I guess I'll check the pump next.

 

[Nordic95]

Did you change the oil filter. I had a few of the frams collaps internally and did the same thing. Changed the filter and all was back to normal.

Nordic95

 

[Pismo10]

Did you change the oil filter. I had a few of the frams collaps internally and did the same thing. Changed the filter and all was back to normal.

Nordic95

Wouldn't that be a nice easy fix..

 

[offshore24]

Sure would. Guess I should have done that before pulling the motor.

 

[DAREDEVIL]

Did you change the oil filter. I had a few of the frams collaps internally and did the same thing. Changed the filter and all was back to normal.

Nordic95

I second that,,,thats why most use WIX Filters in racing.

Fram are not really the best and they do collapse some times.

 

[MERPerformance]

I would inspect all rod bearings before installing the pan back on, just because you inspected #1 rod & main doesn't mean any of the others are not damaged. You really don't need to check the mains, since that oil is coming from the mains. I had a customer collasp a filter and see the oil pressure was low and the warning buzzer was sounding. He thought the two were tied together and kept going, needless to say he had a big lock-up!