5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

[RangerDude]

hi im new here and hoping to get some help, awesome site by the way.
i'll try to break down this problem the best i could..

2002 glasstron, carburated 5.0 volvo penta ORIGINALLY, just replaced with a carburated 5.7 long block, SX-M outdrive.

problem:
-had starter issues and while repeatedly starting the motor trying to see if it was resolved after replacing the starter the boat overheated (temp shot to 225) so i immidiately shut it off.
-realized the water muffs slipped down when water was turned on.
-boat ran for probably 5-6 min w/o water.
-impeller was obviously done for so i replaced it. the old one had 1 vane left.
-now heres the problem.. its not sucking up water! the motor was started but no water was coming out of the exhaust. idled for about 30sec and i shut off the motor in fear of ruining the new impeller running it w/o water.

things ive tried checking:
-pulled the inlet hose off the impeller and checked water flow in the hose. water will come out of the outdrive when the garden hose is stuck into the end of the inlet hose, but not out of the inlet hose when the muffs are on the outdrive.
-pulled the hose that goes from the impeller unit to the thermostat. there is no water reaching the thermostat.
-checked if maybe i switched the hoses on the impeller unit on accident by taking the water inlet hose and switching it between the 2 ends of the impeller unit w/ the one of the ends open. neither pumped water.
-flushed out both hoses that go to the impeller unit with water to get any of the remaining broken vanes out of them.
-flushed out the thermostat housing as well the best i could w/o taking it off.
-flushed out the water pump the best i could as well through the inlet hose.

other things and questions:
-the water pump is new
-the new impeller seems to be the exact one as the original but it came with 4 or 5 gaskets which did not match the bolt pattern. i took one of them and used it anyways by stretching it over the bolts. i did some research online and found that i dont need the gasket, just the impeller and oring. could that be a problem by possibly spacing the housing and not sealing the system?
-does the water pump aid the impeller in sucking up water or just circulate it in the block? is there supposed to be like a vacuume in the system requireing it to be completely sealed (all hoses on) to pull water up from the outdrive?
-im pretty sure there is no impeller in this outdrive.
-the impeller vanes were spun in the correct direction during install.
-just to double check, where does the water inlet hose from the outdrive go? top or bottom? the engine turns clockwise.
-is there anything that could be clogged which i missed?
-i used almost the full tube of the supplied glycerin on the impeller but after a few quick starts trying to diagnose the problem i can hear that the glycerin starting to wear out because the impeller squeeks to a stop when the engine is shut off. i read somewhere here that i can use dishsoap to lube it up, is that safe? i am afraid of ruining the impeller again while trying to diagonse the problem if its not getting water.
-the inside of the impeller housing was slightly grooved up but not terribly bad.
-the inside of the plastic ends of the impeller housing were bubbled up, most likely from the original engine which overheated and commited suicide. i dont think it would restrict the water flow much but should i silicone the space between the plastic and brass housing to prevent air from entering? i think the plastic might have warped because the ends arent very tight in the housing.
-is it possible that i need to wait longer for it to pump water? i would assume 30 sec is long enough..
-how long will it take to destroy a new impeller without water flow w/ the engine just idling? about a min?
-is there anything else that might be damaged from the short overheat that caused the initial problem?
-is there anything in the outdrive preventing water from being pumped in?
-do i need to get air out of the system somehow maybe?
-the outdrive is going in for probably an overdue service on tuesday since i know nothing about it and would rather not risk messing something up.

sorry for this novel of a first post.. im just hoping to narrow it down the best i can! thanks for any help!!

 

[Don S]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

All those missing vanes is your problem. You have to find them. I would pull the pump off and check it carefully.
Pull the thermostat housing and check all the passages for impeller vanes.

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

a hand full came out of the impeller housing hoses. i stuck a garden hose into both openings of the thermostat housing and the water pump water inlet, nothing really came out that i noticed. you think i should still pull the thermostat and water pump off to double check?

if i hook up the water inlet hose on the impeller housing up but leave the outlet hose off, turn the water on, and start the motor.. shouldnt the impeller pump water through it regardless? because right now it is not..

 

[Don S]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

Your question

if i hook up the water inlet hose on the impeller housing up but leave the outlet hose off, turn the water on, and start the motor.. shouldnt the impeller pump water through it regardless? because right now it is not..

My previous answer.

I would pull the pump off and check it carefully.

Where else could the problem be?

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

well the impeller isnt pulling any water up to it, let alone up to the thermostat housing. even if the thermostat and water pump are clogged shouldnt water still be flowing past the impeller? or does the water pump assist the impeller in drawing the water up to the motor, at which point id have to have all the hoses on and inspect the thermostat and water pump carefully like you said twice?

thanks for the help thus far..

 

[Don S]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

If you can disconnect both hoses from the pump, then hook the garden hose to the inlet side of the pump, turn the hose on and start the engine and nothing comes out the outlet hose, then the problem is your pump.

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

thanks for the diagrams don!

i hooked the garden hose to the impeller inlet and it pumps out fine from the outlet end. the boat also has through-hull exhaust and the water comes out of the tailpipes with the garden hose hooked up to both the impeller inlet and the water pump inlet, so the impeller pump and water pump seem to be working the way they should. i also took off the thermostat housing like you said and pulled out 3 full impeller vanes which were blocking the first passage! i also inspected the water pump the best i could w/ a flashlight from the inlet hose and the big allen bolt hole and it looks to be all good.
now, i think the problem lies somewhere in the outdrive because when i backflush it the water comes out fine out of the outdrive.. yet when i have the muffs on, the water does not go up through the hull into the engine compartment.

basically, the impeller seems to work fine.. the water pump seems to work fine.. but i think something in the outdrive is blocking the water from coming up freely. what do you think it could be? i checked the hoses and theyre clear all the way to the outdrive/hull..

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

basically, if i hook up the garden hose to the impeller inlet it cycles water through and everything works the way it should. yet when the muffs are on the outdrive, it wont pull the water from the outdrive through to the impeller... therefore i think the problem lies somewhere in the outdrive.. what do you think it could be??

by the way, i hope they pay you for this because you respond fast w/ good knowledgable answers!!

 

[Don S]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

with the garden hose hooked up to both the impeller inlet and the water pump inlet,

This is confusing, what is this impeller inlet AND water pump inlet. there is only one raw water pump on your engine that you hook water to, the other pump (I assume you are talking about) is the circulation pump. (Item 14 in the center drawing in my previcious post.) All the circ pump does is circulate water in the engine, has nothing what so ever to do with the water going out the exhaust.

basically, if i hook up the garden hose to the impeller inlet it cycles water through and everything works the way it should. yet when the muffs are on the outdrive, it wont pull the water from the outdrive through to the impeller...

NOW, I finally understand your question.
Have you tried putting the boat in the water to see if it will pull water up then? I have seen many times that people try to run them without enough water pressure and volume from the hose and it just doesn't work.
The other thing is there is an air leak somewhere on the intake line to the pump.

Read this link, it should help you locate the problem.
http://www.4shared.com/account/file..._Overheat_Diagnosis.html?sId=CZg1wQh4utZ7R42S

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

sorry for the confusion, i meant i tried hooking up the garden hose at 2 different locations at separate times, once at the raw water pump inlet and another at the circulation pump inlet. both seemed to work fine.

now i think ive narrowed down the problem.. with the garden hose hooked up to the inlet side of raw water pump everything cycles throught the way it should.. BUT, there is a pretty big water leak (squirts water out of the boat, haha) at the outlet end of the raw water pump. so im assuming that there is probably a big air leak at the inlet side as well. the 2 plastic ends that go into the brass housing are both really loose (probably warped) and dont seem to seal well, most likely due to the previous engines massive overheat-to-destruction, the insides of the plastic tubes are bubbled up as well from heat. i am assuming this is the cause of my problem..? what can i do now, replace the whole cover or are new ends available by themselves which just press in?

im also going to pull off the clean out cover on the SX-M outdrive and check it for any debris that could be clogging the water passage like that pdf says. thanks for that file, its really helpful..

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

i know its a little hack, but what if i took some jb-weld and sealed up the raw water pump housing at the plastic inserts..?

either way it will be replaced but i would love to fix this asap to get out on the lake!!

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

PROBLEM SOLVED!!

got a new pump cover, threw it in, and started it up to find a properly working boat again! thanks for all the help don..

 

[RangerDude]

Re: 5.7L/SX-M.. New Impeller Not Pumping Water.. please help!!

ya thanks, the new cover is all brass too.. so no more stupid plastic inserts either that warp and leak!