Help! 502 motor, low oil pressure, Any ideas?
11-03-2006, 10:14 AM
#1
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Help! 502 motor, low oil pressure, Any ideas?
Just unstalled a rebuilt motor in my boat that was done by a local machine shop They put in new rings, main/rod/cam bearings, oil pump, cam, heads redone, roller rockers, etc.
Machine shop tested block and heads and gave them a good bill of health. I made sure I primed the motor with a drill before I started it. Once it started the alarm immediately went off and I noticed the oil pressure gauge was reading very low. I hooked a mechanical guage to it and confirmed my fear of about 5 psi @ 800rpm. At 1500rpm it rose slowly to only 16psi.
Could there be a problem internally that the machine shop did or did not do like a oil plug internally?
Before I go back to them, I wanted to eliminate all possibilities.
Machine shop tested block and heads and gave them a good bill of health. I made sure I primed the motor with a drill before I started it. Once it started the alarm immediately went off and I noticed the oil pressure gauge was reading very low. I hooked a mechanical guage to it and confirmed my fear of about 5 psi @ 800rpm. At 1500rpm it rose slowly to only 16psi.
Could there be a problem internally that the machine shop did or did not do like a oil plug internally?
Before I go back to them, I wanted to eliminate all possibilities.
11-03-2006, 11:01 AM
#2
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Re: Help! 502 motor, low oil pressure, Any ideas?
I just checked the second motor which is still on the engine stand with a drill and a mechanical pressure gauge. That one reads about 5 psi as well.
I'm thinking internal oil leak.......
Anybody else have any ideas or concurr?
I'm thinking internal oil leak.......
Anybody else have any ideas or concurr?
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11-03-2006, 12:26 PM
#4
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Re: Help! 502 motor, low oil pressure, Any ideas?
Are the oil hoses hooked up properly? Oil goes out of the engine on the side of the adapter and back in in the center.
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11-03-2006, 08:57 PM
#8
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Re: Help! 502 motor, low oil pressure, Any ideas?
PatriYatch: Yes, hoses are in the right place. The hose ends and connect points on my gen 6 motors were made to only go in one place from the factory so they took away the possibility of confusing the ends.
11-04-2006, 07:33 AM
#9
Registered
Re: Help! 502 motor, low oil pressure, Any ideas?
It would take huge clearences in the bearings to only make 5psi on cold startup. And on both engines! I agree with the other guys about the galley plugs. Pull an intake and take a look.
11-04-2006, 07:38 AM
#10
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Re: Help! 502 motor, low oil pressure, Any ideas?
Originally Posted by stevesxm
galley plugs times 3
The other option is that they have left out the bypass valves on the oil filter pad in the block. There are pictures on this thread http://www.offshoreonly.com/forums/s...ssure+problems.From what I have seen here repeatedly,
Do not run a new motor without checking oil pressure with a drill and the correct drill adapter. If you can not generate at least 50-60 psi this way then don't bother going any further.
I would also suggest you do this with a screw on oil filter on to the engine before connecting all of your oil cooler rigging. That way you know where you should be when all those lines are attached and where to look if there is a problem.
Good luck
