Engine is a 2000 7.4 MPI (Gen Vi). Its raw water cooled and has been running in salt water since late 1999. Prolly got close to 1500 hours. Now I understand that normally there should be no more questions and its time to repower but I just cannot afford it now so I am trying to salvage for another year or two. So far, I know that it is not the oil cooler and there is no water getting into cylinders. It runs well on the hose. I have changed the oil twice and still looks like chocolate milk. I guess the worst case would be that the block is cracked but where else should I start? Could it be any of the manifolds or risers and not cause water in cylinders? Head gasket maybe (i did heads 3 years ago). Just looking for some more insight here before i call it a season.

Thanks guys!

13 years of salt water running? It was a good run, time to repower. Not worth the cheap fix imo

could pull intake and check head to intake water ports for errision.

Possible things could be intake manifold, head gaskets. Alot of hours but not even a year in salt ?


John jr

I know... it was a real good run!!! That motor has taken me to North to Nantuket Island and to the south to Baltimore... all running out of Queens!!! I just thought I could hold it together for another year or two. I guess I will pull it apart and see. Someone mentioned that I should do some sort of leak test before tearing it apart. Can anyone explain this to me. And how will this help me find an internal leak into my crank case??? Been 13 years in salt Fenderjack... 13 years!

Agreed. Also if it was not winterized properly, you'll know when you pull the intake as they always seem to crack in the lifter valley.

Okay so I pulled the intake and sure enough there is all kinds of mess going on. Lots of rust and corrosion... nothing obvious as far as cracks go but I do believe this is my problem (I hope anyway). There was a bunch of white goo around inside of distributor hole... and some beaded water under manifold and sitting on top of the tin pan that covers the lifter valley. What's the move here? Replace the manifold and gaskets? Or shoud I take it to a machine shop and have them check for cracks then replace gaskets?

Your thoughts much appreciated...

Thanks.

If the exhaust manifolds and risers are cast iron, I would check there first.

pull thermostat housing and inside the water port,tap the floor of the water passage.bet its porous there.also,are the water port openings all corroded?might be able to use diesel silicone to seal up the ports,both sides of the gasket.

rotted mani's would put water in the the cylinders.he doesn't have that,,yet.