Port engine oil pressure has been rock solid this season until the last couple of times we've taken her out. At low / mid RPM (up to say, 1900 - 2000 RPM) the pressure stays steady at about 60+ PSI. The 2nd last trip out I pushed the engines some (about 2400 - 2600 RPM and noticed the port engine's oil pressure gauge was swinging back and forth (down to maybe 30 psi and the back to normal point). If I back down on the RPM's to our normal range (about 1700 to 1900) the oil pressure returns to its normal point and stays there - no fluctuation.
I thought possibly the level was low but after shutting down the engine and waiting about 15 minutes, the dip stick reading is right at Full.
Anyone have any ideas on what to check next or possible cause? Also, with a steady oil pressure in the range I stated, would running the engine NOT be advisable. She gets pulled out of the water in 2 weeks and we have a yearly trip we've been prepping for.
Thx,
Bill
318 oil pressure fluctuation
318 oil pressure fluctuation
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge to be sold (updtd 1-1-22)
"Sunset Seeker Too" (SS2)
'88 41' Marquis hardtop. (as of 1/1/22)
Located in Aurora, In.
Always fresh water.
"Sunset Seeker"
'88 32' Sedan Bridge to be sold (updtd 1-1-22)
"Sunset Seeker Too" (SS2)
'88 41' Marquis hardtop. (as of 1/1/22)
Located in Aurora, In.
Always fresh water.
Re: 318 oil pressure fluctuation
Probably just a sender. I would connect a mechanical gauge and operate the boat under the same conditions. If the mechanical gauge does the same thing, then you have a problem. It doesn't sound like an engine problem the way you describe it.
Chris Hamann
Lakeland Auto & Marine
Port Clinton, Ohio
Lakeland Auto & Marine
Port Clinton, Ohio
Re: 318 oil pressure fluctuation
It could also be a bad connection (ground or sensed wire). That said, you definitively want to put a mechanical gage on it to be sure!
Of course, the electrical gage will behave itself when you do but...
Jeff
Of course, the electrical gage will behave itself when you do but...
Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
-
- Site Admin
- Posts: 410
- Joined: Sat Jul 12, 2014 6:18 am
- Location: Kentucky
Re: 318 oil pressure fluctuation
I had a similar issue a few years ago. Jeff is right on sensors go bad and grounds wires etc. In this case my sensor was leaking. Make a heck of a mess... Was normal at low RPMs but like yours the pressure was forcing oil out of the sensor and well a mess ... this is the second sensor I have had go bad. Quality is an issue. I now check mine often for leaks !
safe harbors,
dave
safe harbors,
dave
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain
Re: 318 oil pressure fluctuation
jUST CHIMING IN TO ADD PERSONAL EXPERIENCE, concurring with the above. 1 - sensors leak, 2- wires loosen or corrode
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD
Re: 318 oil pressure fluctuation
I had bad luck with the oil pressure switches--had to replace one a year for a while. Not sure why.
Note: Everyone with a Chrysler small block needs to keep an eye on that tiny tube going from the motor to the block with the oil switch and sensor. They tend to leak, and in a place where you can easily miss it. I replaced them both (twin engines) with fuel pressure gage stuff.
Jeff
Note: Everyone with a Chrysler small block needs to keep an eye on that tiny tube going from the motor to the block with the oil switch and sensor. They tend to leak, and in a place where you can easily miss it. I replaced them both (twin engines) with fuel pressure gage stuff.
Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington