Overheating Volvo SX, Where is my water

[Superwhitey]

I'm having a overheating problem on my 2000 Larson 5.0 with Volvo SX outdrive. I have taken off all hoses and had it on the muffs. Shouldn't the water pressure force water through the drive and through the transom. I have a seawater pump on the front of engine, but I have disconnected the hose coming through the transom before it gets there. Is there something that will stop water through the outdrive. The pickup ports look clean and clear where the muffs go. Im baffeled, and would really appreciate some help

 

[Chad Flaugher]

If your thermostat is stuck in the motor, it will not circulate water within the motor. It's usually a cheap, easy, DIY, fix. If that doesn't fix the problem, you'll still have a brand new thermostat, which is something that usually goes out once or twice during the lifetime of a engine.

 

[Dave-R]

So you have taken the hose off the outdrive back behind the engine, and can't get any water thru the muffs? Try running water backwards thru the same pickup tube, to see if you have sucked up a rag or something. If you can't get any flow that way I would pull the drive,and check out the pickup hose and flush down from there also. If you finally get flow check each hose as you go. Dave R.

 

[Superwhitey]

Thanks Dave-R, I'll try that as soon as the weather warms a little.

 

[Silverton34c]

Depending where you live, down south we have muddobbers that will make a mud nest in your hose blocking water passage.

 

[HorizonblueDK]

Inside the outdrive, between the upper and lower unit, there is a cupper pipe, in which the cooling water flows. This can leak due to corrosion. I purchased a secondhand SX drive some years ago, and just for safety measure, I took it apart. The pipe was not corroded, but for some reason, it was not seated correctly. If I had just installed the outdrive on my boat, it could not have drawn much water into the engine.