oil pressure
 

oil pressure has always been rite at or around 60psi. I have noticed the last couple times it has been down around 40 and even lower, especially at idle. Oil pump?

Oil pumps seldom ever fail for the life of an engine. Oil pressure for the most part is determined by bearing clearances. What oil weight are you running and do you think it may need changing. Best weight would be a 15-50 or 20-50.

10-30 mobile one. I changed oil in both motors a month ago. I check it before i start it everytime and it seems to be very clean. Is 10-30 not a good weight for boats?

if pressure is down, clearances are opening up some. i would run a straight 40 or 50. if you can't get synthetic in that weight, a PA grade. pennzoil or q-state...

+1

10-30 is not good enough for the heat and load on a marine engine. Most popular oil around here seems to be the Mobile 1 15-50. You can get it in the 5 qt. jugs at Wally World. You could use straight 40 or 50 but personally I prefere the multi-vis to assure good lubrication during starting cold especially if running a larger pan.

Could i have done any damage running the 10-30? Do the clearences open up due to wear?

I ran Mobile 1 15w50 in my Chris Craft Stinger. Not sure if it is rated for marine use or not but we had to pull one engine down as a "pink" rod broke in half in the center (weird, I know). There was no measurable wear on the engine after 300 hours. Currently I use Mercury full synthetic 25w-40 in my Fountain. Oil pressure will fall off at idle especially if you come off of some fast running. I would not recommend running 10-30. Do you have an oil temp gauge?

Yes clearances will become larger with wear but were' talking thousandths here. 40lbs of pressure isn't that low. May just be the oil breaking down when hot. At this point there's nothing you can do except change to good stuff and run it.

Yes i have oil temp gauges. Now that you mention It that engines oil temp always got hotter when running the boat over 4grand. I never understood why but never thought much of it.

I was thinking the same thing but ran the boat all last year and the presure was pretty steady at 60. That engine was rebuilt and had 20 hours on it when I bought the boat (so I was told anyway)

What was the oil temp? both engines running the same oil temp?? if one is running much higher then other you have something to look into...

A BBC will eat bearings if you cant keep the pressure up at idle 15-30 is normal, I personally would not accept less then 55-65 under way hot or cold...

I run HV pumps with shims I get 80 cold running and idle, once I am warmed up, it has 60-70 running and 35-40 at idle, I learned the hard way you need a good oil pressure on BBC ... I went through hell a few years ago and it was all because I didn't have the right pressures/pumps

I am having the same issues in my 454. Pressure is up around 60 when cold after it warms up it's around 40 when cruising, after coming off a hard run it drops low like down to 10 at idle speeds, goes up to 15-20 in neutral but under a load back to 10 until I give it some rpms then back up. Thought the oil was getting hot so I checked my cooler and it's all good. Does anyone know if these motors have a thermostat for the oil?

Gonna change my oil tonight. I use merc 25w-40 or is it 15w-40. Either way I'm switching and gonna try valvoline racing I think its 20w-50. I was told straight 50 is way to heavy I'll post any changes tomorrow since I'll have the boat out.

Good luck with yours.

minimal 10psi per 1000 rpm.... I woukda not accept less... now also make sure senders and gauges are accurate... put on a mechanical gauge to be sure... you could have senders off too...they are electric...

change the oil and go from there . could simply be oil dilution . did you have a hard time starting engine ect . does the oil smell like fuel ?? alot can happen to oil . if you suspect clearence issues open up youre filter . proof is in the pudding

I had trouble in the spring starting it for the first time but that was I believe a battery issue. It starts fine everytime now.

I'm hoping it's something with the oil. Oh and I do have a mechanical gauge in to verify.

the reason i asked about prob starting , if you have access fuel in the oil it will show low oil pressure. flooding of the engine ect . you need to change the oil and see what happens

Oil was black and not much viscosity to it. Wierd for only being out a half a dozen times. No shavings in the filter either. I'm running it on the third so we'll see how it does when hot.

I spun a main bearing last year, But it only rotated about 3/4 inch on number 2 main. When the motor got hot the pressure would drop sometimes to around ten and my alarm would just beep a couple times, But as soon as you gave it just a little throttle it would jump up to 40 lbs. No metal in filter(cut it apart) changed oil, a little better until it warmed up. This was a stock 330 with around 300 hours on it (stock).

Oil stayed up around 20 after a descent run, and I figure thats pretty good with mid 90 temps all week long. I'm thinking oil is getting in the crankcase some how so its either from the carb or fuel pump.