Low Oil Pressure Universl 5416, Ericson 30+

[sailorman37]

I didn't like the idiot light set-up on the Universal 5416 when I became the new owner of a 30+ so I took out the sender and fitted in a proper adapter and oil pressure transmitter. To my shock, after fitting up the transmitter, the oil pressure reads about 1 lb or at most 2 lbs, even at high rpms. Not believing the results, since the engine doesn't smoke and it seems to run fine, I took out the transmitter and attached it to a known air pressure to which the transmitter and gauge tested out OK. So, I really have basically zero oil pressure at the end of the oil passage where the transmitter is fitted.

(The idiot light never lit since I found it was burned out.)

My thoughts are the oil pick up is clogged, the oil pump is bad, or the bearings are horribly worn.

Option 1 or 2 seems most reasonable since the engine runs fine without smoking. Also, dumping in high viscosity Lucas Oil didn't increase the pressure. I also fitted in a new relief spring and ball without any change in pressure.

Regarding option 1. Looking at the diagrams, I am not sure if I can easily disassemble the oil pump in place. Does anyone know If that is possible?

Option 2. Is there a way to blow air back down the intake pipe to the sump to clear out any debris?

Any other ideas would be appreciated.

 

[sailorman37]

universal 5416

Or, does anyone have the shop manual for the 5416 that shows details on the oil pump? I have copy of the service manual (in the database)), but it doesn't show details around the pump.

thanks

 

[rwthomas1]

I have a hard time believing that the engine is running, and continues to run, with 1-2psi oil pressure. All my experience says that it would quickly throw a rod with so little pressure. I would find a reliable MECHANICAL oil pressure guage and test with that. RT

 

[sleather]

So, I really have basically zero oil pressure at the end of the oil passage where the transmitter is fitted.

Bet there's a blockage somewhere in the oil gallery Pull the sending unit and stand by with a bucket when it starts.

 

[sailorman37]

Agreed that it is hard to believe that the engine can run with so little oil pressure. Just to double check my earlier calibration of the transmitter i'll hook up a mechanical gauge at the block. I have to get an extension nipple for the for the gauge. Hopefully I can get that tonight and give it a go.

 

[sailorman37]

bought the required fittings for the mechanical gauge, and again checked calibration against a known source. Checked out OK over a normal range. Hooked it up, started the engine and as expected - zero oil pressure. Looking into the valve cover opening, I can see some oil on the pieces as it's running. Took the oil gauge off and found the hose to the gauge is full of oil. So, it proves the pump is moving some oil, but not enough to raise the pressure at the far end of the galley where the gauge or transmitter is located. After removing the gauge, I blew air back through the galley to make sure it was open to the gauge/transmitter.

I think I'm back to the same options:

1.bad oil pump
2. plugged oil sump screen
3. horribly worn bearings

It's hard for me to believe the bearings could be that worn with the engine still running fine. Any ideas on how to clean the screen without pulling the engine to get to the oil pan? Any other ideas would be appreciated.

Brad

 

[mherrcat]

According to the part listing on the Torresen Marine site the pressure "switch" is rated at 6 - 8 psi. That seems like a low pressure to begin with and I wonder if the normal pressure is too low to properly register with the sender you have installed. Even the mechanical gauge you show is probably accurate to +/- "x" psi; maybe the normal pressure is not registering?

I have a 30+ with the M-18 engine and a light/buzzer low oil pressure alarm. I have never had any problems and my engine has over 2,600 hrs on it.

 

[rwthomas1]

The next thing I would try is to run the engine with the mechanical gauge removed and lead some hose from the oil pressure tap point to a bucket, etc. I would want to see how much oil volume is present. No oil pressure is certainly a problem. If pulling the engine is necessary, then do it. Engines are expensive. If its just a pump, screen cleaning, or even bearings, that is cheap compared to what happens when a connecting rod comes loose....

Another idea is to try and find another tap point at some other area of the oil passage system. I still have a very hard time believing that this engine is staying together with no pressure!

RT

 

[sailorman37]

I checked the idiot light sendor against a pressure gauge and it trips at about 14 psi. Not sure if it was the original sender, but 14 psi seems about right. My mechanical gauge was reading OK at the 5 psi range so I trust the 0 reading.

I was thinking about taking off the oil filter and rigging a hose, tee and gauge at that point. That should be the highest pressure immediately after the pump. Its going to take some creative plumbing so it may take a few days for an answer.

 

[Emerald]

Is the oil filter a spin on? Have you replaced it yet if it is? Long shot, but they have a bypass valve in them (typically), and stranger things have happened.

Regarding your three points of failure, if your rod bearings were that trashed, and figure the rods would go before the mains, I'd expect to hear it with even a little RPM. Yes, I know, it sounds like a diesel e.g. on the verge of destruction anyway, but does it sound like it's a diesel that's got the rod bearing knock changing with RPM amongst all the other "music"?....

 

[sailorman37]

I think it sounds pretty good. I don't hear any imminent rod or bearing disaster, but I'm not an expert.

It does have a spin on filter, NAPA Gold FF 3390. Used same brand in last oil change, since that is what the PO had on the engine. (What other brand and model are people using on the 5416?) I'll try replacing at that same time I make up the bypass line and gauge. I have not replaced the oil filter since changing over to the oil transmitter and the beginning of this saga, so the filter could be suspect.