Help with a 5.0 EFI impeller water flow

[rothfm]

Posting for a Friend..I'm an outboard guy and his first boat....Here goes.

New to him 2003 5.0 Efi with Alpha Gen2. It has a heat exchanger(fresh water cooled), and fuel cooler from what I can gather. Outdrive was on bench all winter getting some new seals, bearings, impeller kit etc.. all that seems fine. Transom got the full Bellows treatment and related parts. I was there and all seems in place, connected, tight etc.

Time for 1st start...Connected Muffs, water on, started up, idled...But got no water flowing out the transom ports. Temp rose slowly past 160 toward 180+ and we shut down. Took off the out drive, and the new seal on top of the impeller housing had torn. It was new and in-place when the outdrive went on. Water never looked like it circulated. The exchanger has good antifreeze mix in it. I opened starboard and port Drains under the risers, and Pink winterizer started to come out both. The prior owner was very meticulous with pre-post season work and maintenance. The water tube and its orings and seals are good, and had mated up too.

Been all over the manuals looking for shutoff's.

Questions are:

1) If water wasnt flowing, could the excessive pressure from the impeller forcing hose water, have affected that Seal?

2) Cant find any Shutoff Valves for the Raw water side from Impeller-THERE IS ONE FOR THE THRU HULL RAW WATER PICKUP AND
IT IS OPEN.

3) We put air, Then hose water into the transom/braket water opening...and still no flow.

Its interesting, as we watched it run, we noticed water working its way out of the top plate seal of the outdrive(top gear housing). It did get some water into that oil chamber. Its been drained again.

HOPING THIS DESCRIPTION WILL TRIGGER SOME THINGS WE ARE MISSING OR CAN LOOK AT.


Thanks

 

[dubs283]

is this an alpha or bravo drive??

edit: re-read and see that is is an alpha drive

is there an engine mounted sea water pump?? you mentioned a thru - hull and if so you need to connect a fake-a-lake to the thru-hull fitting to supply cooling water to the engine

 

[rothfm]

Yes, there is an engine mounted Water pump, belt driven...I believe that sucks from the thru-hull. What is a Fake-the-lake setup?. Isnt the muff's and hose supposed to also provide adequate "raw" or outside water via the outdrive impeller as well? Wondering why we dont have circulation via the muffs.

Thanks for the reply.

 

[dubs283]

you need to supply water to both the drive AND the thru-hull fitting, the drive sea water pump does not provide any cooling water for the engine - it only cools the drive and then dumps water at the transom assy, check and you will see there is no water passage hose between the bell housing and the gimble housing

the sea water pump on the engine gets water from the thru-hull and NOT the drive - chances are you now need a new impeller in the engine mounted pump

the alpha drive pump does not provide ample cooling water for the whole closed cooling system, this is why there is a pump on the motor

 

[rothfm]

Hmm Thanks all. Learned a little more from a boat shop today also. brings up a new round of questions. Appreciate the help.

I get it now-sort of. But the lower unit pickup, isnt going anywhere. Yes, it appears to be blocked from going thru the hull apparantly--but at the same time, I doesn't appear to come out anywhere. When on the muffs, just water leaks out normal places, after starting the motor, nothing changes, like we are not flowing water to anyplace, via the lower pickup.

Looking closely at the outdrive lower pickup water path, it seems to just come up the inside tube to the top, into the bell housing hose, and then there is that plastic thru hull thing. I'm guessing we are plated off inside the boat at the transom bracket. Everything is still connected in back like an original setup. nothing has been disconnected. It also doesnt appear that there is any water Jacket in that loop at all--IF thats the case, hows that cooling the outdrive exactly as its a straight shot up? Should we be removing the rubber hose behind the Bell, and letting it just dump out to initiate flow???

Am I understanding correctly that some thur-hull setups do not use a lower unit impeller at all? Ive read where people have taken them out....and besides, at speed isnt water forced in by speed/force anyway??? But in my case it would have to exit somewhere to provide any flow benefit-which it doesnt seem to.

Ive seen talk about outdrive showers, Is that way? Because they dont bring in lower unit water at all via the impeller?

 

[rothfm]

Hmm Thanks all. Learned a little more from a boat shop today also. brings up a new round of questions. Appreciate the help.

I get it now-sort of. But the lower unit pickup, isnt going anywhere. Yes, it appears to be blocked from going thru the hull apparantly--but at the same time, I doesn't appear to come out anywhere. When on the muffs, just water leaks out normal places, after starting the motor, nothing changes, like we are not flowing water to anyplace, via the lower pickup.

Looking closely at the outdrive lower pickup water path, it seems to just come up the inside tube to the top, into the bell housing hose, and then there is that plastic thru hull thing. I'm guessing we are plated off inside the boat at the transom bracket. Everything is still connected in back like an original setup. nothing has been disconnected. It also doesnt appear that there is any water Jacket in that loop at all--IF thats the case, hows that cooling the outdrive exactly as its a straight shot up? Should we be removing the rubber hose behind the Bell, and letting it just dump out to initiate flow???

Am I understanding correctly that some thur-hull setups do not use a lower unit impeller at all? Ive read where people have taken them out....and besides, at speed isnt water forced in by speed/force anyway??? But in my case it would have to exit somewhere to provide any flow benefit-which it doesnt seem to.

Ive seen talk about outdrive showers, Is that way? Because they dont bring in lower unit water at all via the impeller?

 

[thumpar]

If you have a thru-hull pickup the drive is not what provides water to cool the engine. You need the device that provides water to the thru-hull pickup to test on land.

 

[rothfm]

Thanks all. Was at friends house today....Confirmed the white Thru-hull Tube is capped. We bought a plunger type flusher. Helped him replace the belt driven raw water impeller(it was toast). Started it up and presto--water out the back. Nice. Temps settled about 160-175 or so.

Had an issue when testing the steering wheel power steering, it stalls the motor for some reason? Maybe Idle rpms too low? But it sounded appropriate. Kinda wierd.

Thanks again

 

[dubs283]

keep in mind the sea water pump in the drive still needs water when you run the engine, otherwise it will burn up

the reason there are two pumps is the drive needs cooling water going through it too, it just dumps the water at the bell housing

you should start a new thread concerning the power steering

 

[rothfm]

Yep, apparantl the Prior owner just capped the drive water, there is no flow. We will open that Bell housing hose and let it run free, or maybe redirect it. But there will be flow.