I Changed the oil in both 454 mags today ..( 89 311) these are reman. Jasper Motors ...both with less than 50 hours.. the port motor got hot this spring from a bad sea pump ..pulled the motor never found a blown gasket but asumed water ingestion was from riser or exhaust gasket ...put it all back together and has been fine ...when I check oil before draining ..the port motor showed NONE ...there has been oil in the bilge but I knew I was changing oil soon so havent cleaned it out ...anyway got prob less than 2 quarts iof oil out of the port motor ...changed both motors ... then ran them afterwards with the motor cover up I could here a knock ..slight ...I shut down Starboard motor and sure enough its from Port Motor and Starboard motor sounds fine ...I have been watching Temps and oil pressure very close siince the episode this spring and temps are fine 150-160 and oil press runs 60lbs while running ..I did notice port motor would drop down to 30-40 lbs at idle and when hot ..but thought it might just be characterisic of that motor .. ANYWAY ..now what ?? Pull the motor ? Run it ? We had planed about a 150 mile trip this weekend ... sure would be bad to be 80 miles up River with only one motor ....

port motor was essentially out of oil,it now has a slight knock,your hot oil pressure is lower than usual(thats what i'm garnering from what your saying). In my opinion your going to see some really ugly rod bearings (first layer of babbitt is probably gone)and scoring on the crank,you may have scuffed the pistons and stuck the rings when you over heated it so it's probably also burning some oil. If it holds 9 qts and you only got 2 out if the other 7 were in the bilge it would look like the valdez,so you probably lost most of it out exhaust. the last time you ran it the oil must have been super hot,i'm surprised you didn't see the gauge twitching to zero too. I would pull it so you don't finish it off completely,Smitty

I agree, it should be pulled and checked before it explodes. It will only hurt itself more.

the compression was fine when we pulled the motor last ime ...I got a buddy to listen tonite ...and he had to really work to hear it ...I need to get an experienced ear to listen to it ....

60 lb running and 30/40 hot at idle are not really out of line. Whats the other engine run?

Cal .. I agree ...starboard motor runs about 60lbs at speed and would drop down to about 40 at idle .. the 20-30 lbs prob was because of low oil ..I ran them lat nite in the cradle and at 900-1000 rpm both motors at 60 ...need someone else with experience to listen ...AND find that leak ...

You have a spun bearing my freind and if you dont have a knock meter I suggest you get one because your friend will only guess. The motors go under alot of load not like a car and for sure by this time you have spun bearings and it is only a matter of time before your rod makes a hole in your oil pan. The person whom put your motor togehter might have put the two piece seals backwards or not enough silicone in the four corners. If you dont have breathers in your motor oil will be forced out too.

Good luck

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Pull it out now.....and save some money....

Save your self some dough....pull the motor or you'll be buying a new block,crank ect...

could be a cracked piston. But I would check the bearing. better safe than sorry.