2004 Volvo Penta 3.0L engine knocking

[spunkyman]

Hiya
2004 Glastron 17ft with a 3.0L original engine (red). Ran fine then the knocking started. Not sure if it threw a rod or 2 but there’s no compression on 1+2 and not really sure what else is going on. Shut her down and took it out of the water.

I have 2 questions. #1 Might this be fixed without just getting a new block installed and spend $5k ? (maybe just replace with a new piston kit and hope cylinder walls aren’t scored and crankshaft isn’t damaged) or #2 - Something catastrophic happened and it’s best to just save the headache and spend the money for a rebuild ?

Ok .. another question. What causes engines to do this out of the blue ? Throw a rod, knock, whatever. I’d really like to know the cause before going further. I know it’s not just a loud valve. There are problems here !

 

[alldodge]

A motor knocks when a rod bearing spins of is damaged. In many cases its because the the journal was not machined correctly.

I'm working on a Merc Reman 454 that has less then 100 hours.

The motor needs to be rebuilt and in most cases (depends on motor hours) it just take the crank to be turned, rods checked for out of round and new bearings. As with any rebuild, clean the block and replace the oil pump

 

[Scott06]

You need to tear it doen to see what is damaged.

Low road take it local machine shop , as outlined quite likely turn the crank and resize the rods do a valve job , may need new pistons if bores are out of round and require boring.

high road, get a reman or new base engine swap the components off your donor long block on to new long block and go boating. Saves some time but costs more…

 

[Scott Danforth]

$5k is $3500 more than taking the motor to a local machine shop

 

[spunkyman]

$5k is $3500 more than taking the motor to a local machine shop

Up here in , nothing is $1500 at the local machine shop !!

 

[Scott Danforth]

Up here in , nothing is $1500 at the local machine shop !!

so drive across the boarder with your busted longblock in the back of the truck, drive back across the boarder with freshly machined longblock in the back of the truck

 

[spunkyman]

so drive across the boarder with your busted longblock in the back of the truck, drive back across the boarder with freshly machined longblock in the back of the truck

Not a terrible idea !!!

 

[spunkyman]

Not a terrible idea !!!

Is @Bondo still in 1000 islands ? Maybe he can suggest a machine shop or a place that has short or long blocks ?

 

[Bondo]

Is @Bondo still in 1000 islands ? Maybe he can suggest a machine shop or a place that has short or long blocks ?

Nope,..... I'm not,..... As far as I know, the 2 automotive machine shops in Watertown, are still Best Machine on Water St. 'n the machine shop next to the Napa store on Mill St,...