5.7 crusader help

I have a pair 2004 5.7 crusader closed cooling. I let them freeze in the driveway i t got down to 20 degrees .I tried to start engines to put antifreeze in them and engines crank but wont run ,it seams like there is a lot of back pressure on them. One engine blow off the 4 in 'exhaust I now put boat in my heated garage , and the starboard engine started and I put in anti freeze , but the port wont stay running and seams like its pluged . any ideas

If it is a closed system you should not have had a problem with the engines freezing unless you did not have the antifreeze right. If it did freeze then check your oil for coolant.

Daleinohio said:

I have a pair 2004 5.7 crusader closed cooling.
I let them freeze in the driveway i t got down to 20 degrees . I tried to start engines to put antifreeze in them and engines crank but wont run ,it seams like there is a lot of back pressure on them. One engine blow off the 4 in 'exhaust I now put boat in my heated garage , and the starboard engine started and I put in anti freeze , but the port wont stay running and seams like its pluged . any ideas

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I first need to ask a question;

If these are truly fitted with a Closed Cooling System (either Half or Full), and if you properly drained down the seawater side of the system, why are you adding antifreeze to anything?

RicardoMarine said:

I first need to ask a question;

If these are truly fitted with a Closed Cooling System (either Half or Full), and if you properly drained down the seawater side of the system, why are you adding antifreeze to anything?

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yes it has a recovery tank on back of engine with pink antifreeze. and a heat exchanger ,I did not drain the sea water side I usually run engines to operating temp and pour in 3 gallons antifreeze in the intake hoses run boat till I see purple antifreeze at outside of boat each which is how I winterize them , then I put boat in my heated garage about 45 degrees . But fall came early this year and I think the sea water side froze The boat is in the garage now at 50 degrees and the starboard side starts and run fine ,but the port side seams like there is a lot of back pressure or blockage and it will not run any ideas/

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Daleinohio said:

yes it has a recovery tank on back of engine with pink antifreeze. and a heat exchanger ,
Just so we're clear......
The Heat Exchanger (via ethylene glycol) is what transfers engine heat into the seawater.
A recovery reservoir catches any expanding coolant, then returns it to the heat exchanger upon the engine cooling back down.

I did not drain the sea water side I usually run engines to operating temp and pour in 3 gallons antifreeze in the intake hoses run boat till I see purple antifreeze at outside of boat each which is how I winterize them ,
You'll do better if you simply drain all seawater from the seawater side of the system.

But fall came early this year and I think the sea water side froze
Case in point!
Just plain ole AIR will not freeze expand and crack our expensive cast iron components!
Residual seawater diluted antifreeze could cause a problem!

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