Blown Head Gasket?

[wakeboarddude]

My friends 2004 malibu, 340 monsoon Gm V8... a little history... the boat was running fine last season, however today I find out it wasnt winterized properly. The boat has been out probably 6 times or so this season with no real problems. After my buddies almost sunk it (first day out), i have now replaced the starter and alternator, and some new plugs. Today we took it for a cruise and within about 10 mins, it was overheating, reaching almost 180 degrees. Boat was blowing white smoke/steam out of the exhaust. I checked everything I could on the water, the intake was not blocked by debris( havent pulled apart the entire coolant system to look for a blockage yet), and I pulled the thermostat (it was open when i pulled it out, and then it closed up.) Checked for water in the oil, doesn't appear to be the case. The serpentine belt running betweeen the oil pump, water pump, and alternator has good tension. From what I can tell the water pump is turning fine.
It seemed like there was no water being sucked through the coolant system. When we were running it on the hose on dry land, there were no problems. The boat seemed to be running great before it overheated, lots of power, runnin smooth.

I have come to my own conclussions, but would love some expert advice.
does this sound like....

1. A cracked manifold due to improper winterization...
2. A blown head gasket...
3. something simple like the water pump failing or?...

Sorry for the long post, just want all the info out there. Thanks in advance, I just want to get this boat fixed cause the sooner that happens the sooner I'm going to go for a rip!

Nigel

 

[wakeboarddude]

Re: Blown Head Gasket?

Oh yah and does anyone know where I could maybe find an online.. or even paper repair manual for this thing. Sure would make life easier to know all the specifics/ fluids/ levels.

 

[Bondo]

Re: Blown Head Gasket?

You've got to tell us Who's Motor,+ Drive it has before we can Help...........

2004 malibu, 340 monsoon Gm V8

That is Not enough..........

 

[wakeboarddude]

Re: Blown Head Gasket?

The engine is an Indmar marine engine, with a V-drive in it.

 

[Don S]

Re: Blown Head Gasket?

Contact Indmar.

 

[Robj]

Re: Blown Head Gasket?

I would first check the simple stuff like the water pump and find out what caused the cooling problem. Once that is resolved, try it again and go from there.

Have a great day

Rob.

 

[180shabah]

Re: Blown Head Gasket?

My first thought is the raw water impeller. you have two water pumps, one that draws water from the lake into the cooling system, the other circulates it through the engine. If the impeller is bad you wont be able to get water into the system for cooling. Did you use one of those "fake-a-lake" things when you ran it at home? Hose probably had enough pressure to keep the engine suplied with cool water.

 

[wakeboarddude]

Re: Blown Head Gasket?

My thoughts were also something wrong with the water pump. I'm a little unfamiliar with this engine. The raw water intake is in the bottom of the boat, i can follow the water hose to the front of the engine, then i get a little confused. It looks like there may be two water pumps, both running on the serpentine belt. I know on my own boat, the water pump is behind the pulley, on the front of the engine, and the impeller is in the leg. However as this boat doesnt have a leg, perhaps what i am seeing is the impeller that is just a unit by itself. I will start there and see what i can find, gotta love the quick learning curve when figuring things out. I am hoping for my friends sake, that this may be a simple problem.....
Still wish i could find a proper manual.

 

[Coors]

Re: Blown Head Gasket?

Trace the hose to the transom, then unhook it at a pump, start it on muffs, and see if you get water.

 

[Bondo]

Re: Blown Head Gasket?

The raw water intake is in the bottom of the boat, i can follow the water hose to the front of the engine, then i get a little confused. It looks like there may be two water pumps, both running on the serpentine belt.

Ayuh,.......
Follow that Hose to the 1st Pump,.... That's the 1 that needs a new Impeller,......
The other 1 is in the center of the motor like Your's.........

 

[180shabah]

Re: Blown Head Gasket?

Trace the hose to the transom, then unhook it at a pump, start it on muffs, and see if you get water.

V-Drive