Engine Knock ...
 

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 ....

Re: Engine Knock ...
 

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

Re: Engine Knock ...
 

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

Re: Engine Knock ...
 

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 ....

Re: Engine Knock ...
 

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

Re: Engine Knock ...
 

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 ...

Re: Engine Knock ...
 

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

www.mesabalancing.com

Re: Engine Knock ...
 

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

Re: Engine Knock ...
 

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

Re: Engine Knock ...
 

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

Re: Engine Knock ...
 

keep em comming guys ...I am going to let someone else listen ....(knowledgable) and also get on of those listening devices ...

Re: Engine Knock ...
 

Mike -

An old mechanics trick is to use a piece of broom stick handle, about two feet long. Press it against the heads, the block, where ever and put your ear on the other end. (Okay, okay - watch for moving parts.) You can ususally narrow down where the noise is coming from. Just like a stethoscope the doctor uses only alot cheaper.

Re: Engine Knock ...
 

Mike, I've used the same concept as "wantsa/hasa" except I use a 3/4 inch hardwood dowel.

If you were running on only two quarts of oil and didn't damage anything you are one LUCKY boater. The key word there being "boater" which translates to "worst luck possible". If you can't determine that the noise is definitely a sticky/stuck valve, I would not run it until you pull it and fix it, otherwise you are just "lighting the fuse". What might cost 2K now might save 6K later. This is something you really don't want to guess at.

Oh yeah, welcome to boating.

My motors run about 45/50psi running and drop to about 35 at idle when hot.

Like you said, get somebody who KNOWS listen to it and go from there. Good luck. Russ

Re: Engine Knock ...
 

Suprised I read through this whole thread and no one has yet stated the obvious. You need to cut the old oil filter open (chisel that is). It will tell the whole story. Flakes of death, pull engine. No flakes, more fact finding.

BT

Re: Engine Knock ...
 

The same thought hit me today ....Yesterday I went to the Land fill and took all my old oil and the suspect oil filters ...so stupid ..

maybe I need a canoe ...

Re: Engine Knock ...
 

"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"
What were problems with this motor after overheating and before you pulled it first time. Where were you getting water that made you look at hd gasket and exhaust??
Sorry if I missed answers to that already, just thought more info might give more answers.?
good luck!

Re: Engine Knock ...
 

When the motor got hot it sucked a bunch of water ..cylinders and in the oil. ... This boat was new to me at the time and my motor guy wanted to pull the motor ....Hindsight shows it wasnt necessary but I did what he suggested.. we pulled heads and had them checked .. never found anything ..new gasket set ..put it back together and been fine since I think it was prob a riser gasket ..( as I was told on OSO) ...now let me restate this is NOT a huge knock ..you got to really listen to hear it..even if it does exist .to me there is a def. differeance when you listen to each motor by itself ...I di ahve a guy that knows what he is doing going to listen/look at it Monday ..

Re: Engine Knock ...
 

Too bad no one was ever able to check out the exhaust, on my boat I had a riser leak and caused a whole lot of **** but before it broke (and while leaking..) it didn't run hot or get water in the oil. Hoping since it is barely a knock it is nothing major and hope it is nothing major. Sure it is actually in the motor and not the drive or something else...either way hopefully it works out..
Rick the rookie...

Re: Engine Knock ...
 

Took the boat to merc dealer and they seem to think its ok ..does seem to have quieted down ...might have been a dry lifter from the low oil ....we did find a leak around the takeoff for remote oil filter ....:)

oh and thanks for all the post .... a lot of good info here ....Mike

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or valve hanging up since they only put gaskets on it, Either way Best of luck!

Re: Engine Knock ...
 

At this point I would take it out and run it like I stole it....if got worried about it just look back at headaches from going through this.. Well maybe run easy for 15-20 mins then check all temps and see what oil looks like. Then hammer down for a few minutes and recheck after short cool down. JMSO

Re: Engine Knock ...
 

I had the heads reworked when we had it out ..even though it only had about 20 hours on it ..

Re: Engine Knock ...
 

with water getting in there hours don't matter much, Thank goodness you don't belong to my cheap ass club. Of oneee.lol

Re: Engine Knock ...
 

with water getting in there hours don't matter much, Thank goodness you don't belong to my cheap ass club. Of oneee.lol

Re: Engine Knock ...
 

The motor got hot - how hot.
It might be that you had a piston start to melt and the eyebrow of the piston is hittting the intake valve.