View Full Version : Oil Pressure???

05-05-2008, 09:10 PM
I changed the oil for the first time myself, and finally got the level right (I did the whole drain it completely and then put in 1 gallon like the Indmar guy suggested...it ended up being too much so I had to pump some out). Anyway, on the first trip out, the oil pressure was almost 60. In my memory, last couple of years it was running 45 or so. I used Rotella instead of Penzoil, although its still 15W-40...could this cause the difference, and should I be worried?

05-06-2008, 12:23 AM
Don't take this the wrong way but i always question why some guys insist on running diesel oil in all their non-diesel vehicles. Just because it's cheap or works in your diesel doesn't make it right for all applications. Rotella was and is designated as a diesel oil, multi grade or not and not even Shell recommends it out of context. If it had all of the API ratings of regular motor oil as specified by the marine mfgrs then they would recommend it, but they don't.

As an example a few ago the mfgrs of aftermarket Harley motors started specifying that the use of Rotella would void any engine warrenties as it was becoming increasingly popular for some to use it in their motors and they prematurely failed due to the fact that the API rating were different as were the viscosity ratings. Too high of oil pressure can also cause seals to prematurely fail as well. So to answer your question as the viscosity properties are probably different than regular motor oils, yes it could be the cause and i wouldn't do it, but that's just my opinion and two cents worth.

05-06-2008, 08:49 AM
Thanks for the reply. I guess I used Rotella based on the responses I read here on 'oil change' threads, the fact that the criteria fit the 'or another oil that has the specifications blah blah blah', and that I can buy Rotella locally without driving all over creation looking for Penzoil Marine. I am a chemist, so I assumed, maybe mistakenly, that a 15W-40 oil with the same specifications would have similar/same properties, including the pressure that it would run at under load...because manufacturers can't sit around all day and list every single oil that would work. I guess I'm not a big believer in 'brand names', and I extended this to my oil change. Hopefully it doesn't turn around and bite me in the @$$.

05-06-2008, 09:00 AM
Helix, you really don't have to use the Penzoil specifically. My dealer uses Mercruiser Marine oil. I used Mobil1 in my last boat without any issues at all and it actually ran quieter, smoother and cooler it seemed. I'm just not a big fan of Rotella in a non-diesel application. You may be able to use it fine but like i said i do know and have heard instances where it definately wasn't the right oil for the application.

05-06-2008, 10:56 AM
I just did my first oil change on my lsv last week...b4 i bought oil i called skiers choice and talked to one of there guys he told me to buy penn. 15w40 he said if it says diesel on it (it does) don't worry its the same thing.. what makes me a little nervous is i couldnt find a penn. pz3 filter so i bought what is supposed to be a match but its about a .5-1" shorter than the penn... filter.
launch box vaporizer (http://mflbvaporizer.com)

05-06-2008, 12:08 PM
Any oil that meets the SJI specs for your engine is fine. Indmar has an oil supplier, Penzoil, so they have a sticker that says use that brand oil. If you do regular oil changes as per the manual and use the right visocity oil, then your engine will be fine. Most problems occur by not doing any maintenance at all. Oil pressure under load should be around 60, and at idle it should be in the low 40s. Every guage will read slightly different, but those numbers are ballpark for a GM 5.7L.
I can't think of any oils that Walmart or Parts shops (Autozone, Pep Boyz, etc.) sell that will void your warranty or cause your engine problems. Proper level is assumed. There are so many opinions about oils, opinions don't make any difference to your engine.

05-06-2008, 12:27 PM
I wouldn't worry about the filter as long as your using a quality one. The real issue with filters is what you can't see, total filtered area and the filter media itself. Check the links below for some good filter info. Turns out that the Penzoil filter is nothing more than a re-badged Fram! I know i won't be using that one!



05-08-2008, 10:10 PM
Funny, if you buy Amsoil 15w40 on the jug it calls it a diesel/marine oil. FOr whatever reason fresh oil always runs at higher PSI, then after some use you will notice the PSI drop to what you consider normal.

05-09-2008, 11:10 AM
Thanks for the info guys. Everything seems to be working fine, but you've reduced my stress levels :) Get on the water...it is warming up!

05-09-2008, 10:20 PM
I have not changed my oil yet, but plan too this season. I do change my oil in my Tahoe and my wife's Silverado, and I have a question about removing the filter on the boat motor.

How do you keep the oil from spilling into the bilge ?

When I remove the filter from the truck engine, I put a bucket under it to catch the oil, but there is no room in the boat. I thought about a bag or something but fear the tempearture of the oil might melt the bag.

05-09-2008, 10:28 PM
I wrap the filter with a rag as I'm spinning it off. I also lay some rags and paper towels in the bilge to catch any oil that does get buy, but as every one knows I have one of those easy to work on DD's. Low Tech but works

05-09-2008, 10:38 PM

I don't change the oil in my Moomba..............I let the dealer take care of it. But in my pre_Moomba days I used to change the oil in my boats. The best way I found to keep the oil filter from dripping into the bilge was to double or triple layer plastic shopping bags and have someone help hold them around the filter as I loosened it. It works nice and you won't have an oil slick when your bilge pump kicks on.

05-14-2008, 04:53 AM
Even Larry (aka EngineNut from Indmar) says Rotella is just fine.
I put a zip lok bag around my oil filter as I spin it off. Very minimal spillage
Hope this helps

05-15-2008, 10:27 AM
I put a sherbet (2 qt?) ice cream bucket under the filter last time. It went in easy and came out the front easy on the DD. Love Buttafew's idea about the freezer bag. Course I'm not as smart as he is-- but then who is?

05-15-2008, 10:53 PM
Break the filter loose so you can spin it by hand. Then put one of the large ziplock freezer bags over it. The bags are fairly thick so you don't have to worry as much about tearing it. When the filter comes off, zip it up so you don't have to worry about any spills while removing it from the boat.

05-17-2008, 08:36 PM
Butta! great idea, ( zip lock) thanks, keep me from trashing so many towels...

05-30-2008, 10:39 AM

I use an old "dry bag" from my canoe days. They are a lot stronger than a zip lock regarding oil temperature, and allow me to take off the filter without the oil mess in my bilge. I picked up an extra one at a garage sale the other day. Typically made of strong vinyl with threads so allows for much higher temperatures with no stress of having it melt. Hope this helps.

05-30-2008, 05:37 PM
Last weekend I used the zip lock bag method and found it to work rather well. I was disappointed in the torque settings that they used at the factory on the stock oil filter. I wound up crushing the oil filter in order to get enough grip to get it off. I took about 15 mins for the the oil to drain, replace the filter, and add the oil.