Boat not picking up water for cooling...HELP!!!

[aaron]

Hi Guys
MY 2003 SANTE was used for the recent AsianProtour in Phuket Thailand.
On the first day, Friday, everything worked fine til the afternoon when boat overheated and was in limp mode.
On checking this out Sat morning, found out no water in the water filter whose metal strainer had a greenish algae covering it ...hence the restriction of water flow.Boat not picking up water? surely it was an impeller problem and on opening the raw water pump, true enough impeller was burned out.Managed to recover 4 or 5 of the blades and i know there are 4 or 5 still in the engine's cooling system.Installed a new impeller and boat ran great all day Sat and Sunday until the final event and ....overheat and limp modeyet again.

On checking this again, noticed water filter not properly screwed back on, hence air intake, hence problem.

Funny thing is, now the boat is not picking up water when it is sitting on water, even with a new impeller.I have checked all hoses for leakages and restrictions.

When the boat is on the trailer, engine runs fine when garden hose with running water was stuffed into the water filter.Guess so since there is water pressure.

Does the engines water pump have an effect on all this???

[skinautique]

RE: Boat not picking up water for cooling...HELP!!!

open up your thermostat housing to check it for impeller chunks and then flush the lines out. I bet your extra blades are plugging things up. Also, check with your dealer. There were some bad water pumps on the 2003 models. This could be the case. There is a date code but I don't remember how to read it.

[aaron]

RE: Boat not picking up water for cooling...HELP!!!

Thanks skinautique for your reply. Since posting my subject above, i had proceeded to read thru other "cooling" posts here in this forum and checking thermostat for impeller chunks seem to be to first thing to sort out.However, there is no dealer here so everyhting is DIY and there are not parts.So, i had remove the 3 bolts holding down the thermo housing but one question, how to remove the housing? by prying open? cos its really stuck to the block!Also, i guess once the housing is removed, i shd cut some gasket material to shape for reinstallation, or can liquid gasket sealant be sufficient?

[wrollema]

This may sound dumb but did you check your water in-take shut off valve?

[83sn2001]

The thermostat housing will probably have to be pryed off with a screwdriver or similar tool. Since you ran it dry again, you may want to check the impeller again. As far as gasket material, you can use liquid gasket,just don't use to much as it may squeeze into the thermostat and cause problems.

[skinautique]

I would contact someone at a CC dealer or the factory and ask them how to check the code on your water pump. I think that is the real culprit but do proceed to check the thermostat housing and flush your lines out.

[NautiqueJeff]

I believe THIS is what skinautique is referring to.

[aaron]

My RW pump has a ZID code, so it isnt one of those referred to in the recall bulletin.
I will proceed to pry open the thermo housing have have a look.

[aaron]

Just opened up the thermo housing, and next to the thermostat there is a small rectangular/oval waterbypass hole , and it is clogged with 4 small impeller bits!
Thanks guys.
Next question, how do i check if the thermostat is working? just dump it in boiling water to see if it opens up???does anyone have the temp spec for this thermo?
Bought a tube of USA made RTV silicone gasket maker...instructions on it say it will work on many things...including thermostat housings

[NautiqueJeff]

Your thermostat should either be a 140* or 160*. Most likely it is a 160*.

[Brownie]

how many hours are on your boat Aaron?

I had a similar problem with my 2003. It has actually worn a groove in the housing, leaving a small void. This little bit of air stopped the pump from priming.

Just last week I left the seacock valve on the flush point open just a little bit and it sent the motor into limp mode after heating up. Once it was closed it ran normal again.

[aaron]

Thanks Brownie.Boat hrs 575( and not a impeller change prior to this episode) There is little wear on the RW pump plate but i decided anyway to put some liquid gasket to make it more "airtight".Running tap water thru the engine shows no leak....so i think it shd work fine when the boat gets back into the water.We shall see.

[Brownie]

Aaron maybe turn that plate around, use the liquid gasket stuff as well. Worked for me. It may still leak as the water coming through the pick up will be at a greater pressure than the tap water. But yeah a water test is your next step.

Aaron, I think I have seen some pics of your boat. Adam Bruce had them.

[nautique4life]

I went through this last summer. I went through everything and came to find out the 3way valve at the front of the engine compartment was stuck. Check that. The plunger has a notch that keeps it in line. Mine somehow moved. I would check that, then your impeller. Good luck

[aaron]

hey guys thanks alot for the support and assistance.
just got back from a wakeboard demo with Adam, Kim ( Korea#1) and "A" ( Asian Pro Tour #1)
Boat sucked up water fine....kept at 161 and 162 at idle when hot.
We did a demo for the MONSOON CUP ( www.monsooncup.com.my)which was a pro tour sailing event here in my country. What i may do, and suggest to you all, is to put in-line after the raw water pump a strainer so that bits of broken impeller wouldn't clog up the rest of the cooling system.In a Mercruiser 350MAG Gen+ engine, the trans oil cooler is placed directly behind the water pump so its really easy to get those broken impeller bits out.