Overheating problem

[Cggx2051]

I have a 2001 glastron gx 205 with a Volvo penta sx gl 5.0 and I went to start it for the first time this year and it started right up but no water was running through the motor on the muffs. I called a mobile mechanic who changed the impeller which was fine but found a loose hose clamp on the oil cooler. Connected the muffs and started it and no luck, mechanic thought it was possible that I wasn't getting enough pressure from the hose at my new house which is on well water not city water. Took it to the lake and still no luck. I appreciate any suggestions. Don't know what else to do. Thanks, Chris

 

[alldodge]

Remove the intake hose from the raw water pump, then connect the muffs to the drive an turn the hose on.
Does any water come out?

 

[Cggx2051]

The boat is in the water now but I did try this last weekend and no water at the intake hose with the muffs and the hose on.

 

[alldodge]

The boat is in the water now but I did try this last weekend and no water at the intake hose with the muffs and the hose on.

Then I would pull the drive, back flush from the pump hose out the stern and also flush the drive. Might be the intake fitting Scott Danforth talks about needing to be replaced every so often

 

[Cggx2051]

I haven't pulled the drive but I did hook up the hose to the intake water line at the impeller and water flowed out the outdrive well.

 

[alldodge]

I haven't pulled the drive but I did hook up the hose to the intake water line at the impeller and water flowed out the outdrive well.

Now that's just really weird. water flows backwards but not forward.
Is this open or closed cooling?
And its a GL what A, B ...etc

 

[Cggx2051]

It's the GL-A and it's the raw water cooling system. No heat exchanger.

 

[alldodge]

Lets look at things from scratch.
Water comes in from the drive and thru the power steering cooler (check cooler for obstruction)

The intake water hose is the one on top of the raw water pump, and the one which goes to the thermostat housing is on the bottom

If all good there, turn water on with muffs and remove the hose going to the thermostat housing (look for obstruction, then water after motor is started)

If you get water, then obstruction is between thermostat housing and exhaust

 

[Cggx2051]

I may go down to the lake in a bit and check for blockages between the impeller(bottom hose) and the thermostat for a blockage but I am still fearing it isn't getting water at the (top hose) intake on the raw water pump. Other than that I need to check the oil cooler for a blockage. Seems unlikely because water flowed out the drive. I'll keep you posted.

 

[Scott Danforth]

from the drive pickup grates, water flows up, thru the pivot pin, thru the problematic fitting thru the hose to the power steering cooler. from the power steering cooler thru an oil cooler if you have it.

from there it goes to the inlet of the raw water pump on the motor. from the raw water pump it goes to the thermostat casting.

from there it splits.....some is always going thru the exhaust to cool, the remainder fills the block, cools the block and heads and when the thermostat opens, exit thru the exhaust

if the mechanic pulled the pump and installed the hoses backward, it would try to spit water back out the drive

if the problematic fitting is corroded, the pump sucks air and doesnt cool

if critters built a nest in the drive, water cant flow

if you sucked up small rocks and gravel, thus plugging the power steering cooler, water cant flow.

 

[Cggx2051]

I went down to the lake and checked to make sure all the hoses were tight and there was no blockage on the hose between the impeller and the thermostat housing and no luck. I'm going to have my mechanic pull the oil cooler and check for a blockage if no luck than maybe the drive needs to come off.

 

[Scott Danforth]

plan on a new impeller too.... the one you just installed is most likely melted now

 

[Cggx2051]

I was on vacation last week and had the mechanic stop by the lake and he said he revved the motor once and it started pumping. He let it warm up to operating temps and everything was fine. I took it out today for a few hours at idle and at different throttle levels and everything worked fine. Can't explain it but it worked! Thanks for all the help!

 

[vwbugman69]

You have a small air leak somewhere. You shouldn't have to rev the engine in order to prime the pump.

 

[Cggx2051]

But it's working great as I've driven it multiple times, what are you suggesting I do?

 

[vwbugman69]

When you say you have driven it multiple times, has the boat stayed in the water or been back on the trailer?