Low Oil Pressure?

Hey all...quick question, I just changed my oil last week and after the oil change, when im running high RPM's my oil pressure is close to 0. I have never had an oil pressure problem before. I put 7 quarts of 15w40 in the engine and a new filter and have had this issue ever since. The boat is a 97 Sunsetter, so I think it has the Monsoon 350...?

Anyhow, could it be just my sending unit? The different type of oil? Should I be worried? Any way to trouble shoot? Thanks in advance all.

I know on mine oil pressure should never go below 20psi @ idle and on higher RPM is will be around 50-60 psi, so running near 0 could mean engine damage if the unit is reading correctly.

Hows the oil on the dipstick?
Any blockages in the oil filter?
Does the presure increase at lower RPM? or is it close to 0 always?

The pressure does increase in lower RPM's and when i put in in neutral and rev the engine, it does make it to 40, which only makes me wonder whats going on and almost makes me think its the oil i put in it.

The oil on the dipstick is just a tad above the normal level and is as clear as oil can be.

The oil filter is brand new so i dont know why there would be a blockage in the oil filter. Obviously the last thing i would want is engine damage, so before i run it any longer i want to find out whats up.

Correct me if im wrong, but somewhere i read that the type of oil you use could affect the pressure...? Im no gear head, but i do know my way around engines, just not to any extremes.

Yes Synthetic oils will cause lower oil pressure, as well when oil is heated it will lower the oil pressure a bit as well.

I am not running synthetic, but i think i had like 10w50 before or something like that, and my dealer told me to use 15w40 instead....did i use the right weight? Is that why my pressure is low? Like i said before...any way to troubleshoot it so i know its just the oil, so i can still run the engine and not be worried? thanks man!

I honestly would be worried until I found out for sure what was wrong. 15w40 is fine and pretty much no matter what oil you put in (synthetic, strieght 40w ect.....) it you should never see 0 psi. Just because an oil filter is new doesnt me it cant fail. What oil filter did you use? Also, just a long shot as "a tad over the normal level" shouldnt make a differance but theres allways the chance you have too much oil in your motor and its flinging around and aereating(SP?) your oil? If you do take the boat out again run it for a minute then check the dipstick for bubbles, this would be a good indication. Could be somthing simple as a bad sender also. Just a couple of thing to think about.

When we do the steering cable on your rig, we will investigate it further. I wish you would have called me about this, but I think it is something we can get resolved pretty easily.

FWIW there is no such thing as a full flow oil system. All systems are bypass oiling. What that means is when an engine is cold or at higher RPM's the oil is redirected back into the oil pan. It is supposed to be pressure dependent. The bypass valve can be at the oil pump, in the block, and a good quality oil filter has one built in. That keeps the oil filter from blowing the seal.

What I would do is replace the filter with a brand new Ford FL1A filter or A/C Delco filter depending on the mount. Then recheck it. If it is still low then you need to put a gauge on it and confirm what the pressure actually is.

DO NOT RUN IT WITH NO OIL PRESSURE!!!

http://www.themalibucrew.com/forums/index.php?showtopic=14830&hl=pressure

Check this thread on The Malibu Crew.. It sound like the sending unit may be your problem but I would check the Canon Plug as well...
Good Luck

Don, thanks man, ill holla at you later man!

Thanks all, good info, ill check on some of this stuff!

Install a manual pressure gauge as a test, the oil actually moves the gauge so pressure is accurate.