dropped oil pressure!!!!!!

[wca_tim]

Re: dropped oil pressure!!!!!!

I would be VERY careful making assumptions aobut what went wrong and whether or not melling takes the hit for the repair, be absolutely certain you know what caused the problem. it would REALLY suck to do this again, eh?

 

[alilley]

Re: dropped oil pressure!!!!!!

yes it would suck to go through it again.

no the pick up was not installed when pump was purchase

how woul you "wrincle" the pick up
how could it have been installed incoprrectly when it was put in the proper place and bolted in?

and right now if it is not a defective pump then what else could it be? that is why the pumo is going back to melling for them to test it and verify weather or not it is the pump that failed. but if it didnt then fail once again i ask what else could it be?

the block was hot tanked decked and everything before it was assembled
we are trying to figure out what caused the issue so we dont have to go through it again

i have asked this before...when the boww raises is it possible for the 3.0 140 horse to suck air in the oil pick up? shoukld we add some baffles to the oil pan to prevent this from happening

 

[picklenjim]

Re: dropped oil pressure!!!!!!

i have asked this before...when the boww raises is it possible for the 3.0 140 horse to suck air in the oil pick up? shoukld we add some baffles to the oil pan to prevent this from happening

Is the pick up more to the front or the rear in the pan? Even if it did suck air momentarily it should have returned to normal when you got on plane. Mercury would have put baffles in the pan if they thought it was necessary. There's tens of thousands of those engines out there.The only possible thing I could figure is if the gear in the pump which is on the pump drive shaft is slipping on the shaft. You could remove the cover on the pump and take that out and see if it will turn on the shaft. That would be a bad pump and I would think they would be liable. Very doubtful though.

 

[alilley]

Re: dropped oil pressure!!!!!!

I would be VERY careful making assumptions aobut what went wrong and whether or not melling takes the hit for the repair, be absolutely certain you know what caused the problem. it would REALLY suck to do this again, eh?

i am questioning howi am assuming here.???

 

[alilley]

Re: dropped oil pressure!!!!!!

Is the pick up more to the front or the rear in the pan? Even if it did suck air momentarily it should have returned to normal when you got on plane. Mercury would have put baffles in the pan if they thought it was necessary. There's tens of thousands of those engines out there.The only possible thing I could figure is if the gear in the pump which is on the pump drive shaft is slipping on the shaft. You could remove the cover on the pump and take that out and see if it will turn on the shaft. That would be a bad pump and I would think they would be liable. Very doubtful though.

the pick up is in the front of the motor. i too agree that mercruiser would have put a baffle in it if they felt that it needed it since they do use that motor so much. we was either just got on plane or was on plane when i heard the motor pull down, i checked the guages and noticed no oil pressure and shut it down...in all honestly i feel that by me hearing a 200 rpm drop that i didnt do is what saved this motor from locking up and be a lot worse then it is.

now when we pulled it off the motor we did take the cover off just to inspect things and for some reason we tilted the pump and one of the gears did fall out littlerally. i do not recall if it was the drive gear or which one it was and did think it was kind of odd that happened.

now back to the 2000$ question........if it is not a falty pump what could have caused it/what could it be?

 

[OldNBold51]

Re: dropped oil pressure!!!!!!

Having rebuilt my engine myself and installing it last summer only to get 55 hrs from it when it developed a knock and redoing it again this year (25 hrs and counting) all I can tell you is I beat my head against the wall wondering what i did wrong initially. It was 1 of 2 things I possibly did and I paid particular attention to those things this time. The thing I think i did was knick the crank when installing the rods. I was too lazy to go into town (45 min round trip) and get some rubber hose to cover the rod bolts. I thought I was being very careful and not knick them inititally. I guess not as I knicked it the second time but saw it immediatley and fixed it right away and made the 45 min trip to get the hose to cover the bolts. It was at this time the dim bulb known as my brain made the connection as to what went wrong the 1st time.

 

[RogersJetboat454]

Re: dropped oil pressure!!!!!!

Just out of curiosity (maybe I missed this while reading through the posts) did anybody take a look at the pressure relief valve/spring while looking over the pump? If the spring is damaged or the valve hung open, this would certainly drop the oil pressure.

I respectfully disagree about the pump not being able to pump solvent. Considering the viscosity of some of the newer style oils (0W-20 or 0W-30 comes to mind), those pumps seem to have no issues pumping those thin oils. In my experience, you can actually blow (with your mouth) into a tight new pump and make the pump act like an air motor similar to a air tool, that gives you some idea as to how tight the tolerances are.

I guess it comes down to a wait and see what Melling has to say about your pump.

 

[alilley]

Re: dropped oil pressure!!!!!!

i did look at where the sprin is to be and the pin is still in there but i thought it looked bent side ways.......i will also add that this is the first time i have EVER had an issue with one of their pumps and i have used plenty

 

[alilley]

Re: dropped oil pressure!!!!!!

up date. . . . . . .got to looking the pump over and noticed that the pressure relief valve was open reached in there with a small screwdriver and barley touched it and it snapped shut. so i am assuming that is what caused the hole issue was that it stuck open. i have yet to send the pump back in but will do it and let you know the results.

in attempts to get the boat back on the water we went ahead and tore the motor down again and in the process #1 connecting rod had changed collors by the crank jernal due to heat. so with me having a 3.o sitting there with a busted block and good rotating assembly we pulled teh crank out of it new bearings switched the rod out (put old piston on "new" rod and in the process of reassembling. the block did get washed out and will be flushed out before it gets fired up.

once i get it to were i feel comfertable fireing it up and get it all worked out running like a top again. what sould i do to "break it in" or in other workds how should i run this motor in?

 

[paultjohnson]

Re: dropped oil pressure!!!!!!

up date. . . . . . .got to looking the pump over and noticed that the pressure relief valve was open reached in there with a small screwdriver and barley touched it and it snapped shut. so i am assuming that is what caused the hole issue was that it stuck open. i have yet to send the pump back in but will do it and let you know the results.

OMG ! All this potentially caused by such a tiny thing...wow:facepalm:

 

[alilley]

Re: dropped oil pressure!!!!!!

ya i know something so small can cause such major issues......o wait a sec we are talking about the boat here not the kids right

 

[alilley]

Re: dropped oil pressure!!!!!!...update....it's alive

Re: dropped oil pressure!!!!!!...update....it's alive

ok so to bring all uf us to speed here on what i have done. some of this was due to finical restrictions....new gasket, new bearings, took oil pump from old motor and crank from old motor (old motor being the one that ran but took on water due to previous owner letting it freeze bust, but ran good and good oil pressure) put all new gaskets on it again, me and dad went through and cleaned the block internally as best we could (i know taking a chance here but due to $$$$ cost involved just could not do it any other way) got every thing reassembledand stuck back in the barge saturday. sunday morning went out tinkered with it a little and got her fired up timing, well close, dad wants to due final set on the water. cant say i dont blame him there. so that will be done next weekend. when we got her fired up she jumped strait to 40 psi on oil at idle and would bump up to 50 above idle (this is with a mechanical guage that we mounted on the motor) we did not have the mechanical guage before issue took place but the electric guage showed a solid 50 psi all the time (i think it is time for a new electric sending unit)

so next set of questions...
since it is only new bearings how long should i hold off before going wot?
how should i "break it in"?
any advise on tuning it or any other advise you all can give will be appreciated and many thanks for the support and help any of you have given as you will never know how greatful i am for it

i am just hoping that i have takin enough asprin to cure this head ach figuratively speaking, the better half asid that if it is a no go this time around, then it is put on the back burner for a wile till we do a complete turn key unit