seriously need some experts help on this one, no water exits manifolds

[stang32]

ok, so i had a post earlier about this but i want to consolidate. this is a 2004 5.7 MPI. bravo set up. the boat came to me overheating. previous owner replaced impeller thermostst (aledgedly) and inspected the manifolds. (yeah right). While running and testing the system ,the feed hose from the RWP to the distributor assembly blew off with lots of water pressure behind it, the diagnoses, clogged manifolds/risers (original) changed them out and the boat ran fine, water exiting as designed.
boat was sold and i was called with concern that the temp does not go up., infrared thermometer confirmed, engine running below 100 deg.
further inspection found the thermostat was missing. i installed one and thats when the fun began.
hose clamp broke on the lower hose going to the manifold from the feed hose and the hose blew off causing the engine bay to fill up with water. .
boat was bailed out and hose reinstalled. once it was back on i ran it and found the tubes before and after the elbows had melted and shutters were cooked. i replaced all these and tested the system. engine stayed under 175 and the manifolds were baking. once out of the water and on muffs i found that again, no water was coming out of the gimbal exhaust.
i replaced the impeller, same issue. i then removed the thermostat and the water would flow once again and all components remained cool.

my conclusion was that the check ball in the tee fitting under the manifold was bad and not allowing water to flow into the manifolds while the boat was heating up(closed thermostat)
i replaced both fittings and i have the same results.
no water coming out of the manifolds when thermostat is installed.
HELP . i have ruled out everything i can think of.

 

[alldodge]

Serial number

 

[stang32]

1a305748

 

[alldodge]

Thank you
You can have anything from 3 to 7 point drain, closed and open cooling and may also have Axius

 

[stang32]

ok, i really didnt look at the block but from what i have seen, there is only 1 drain plug, and that on the thermostat housing. there is actually not even a distribution assembly, only an elbow connecting the hoses. standard cooling. im not certain if the water jackets in the block have drain plugs or they are connected to hoses going to the water system.

 

[alldodge]

Saying check balls I'm assuming this is you system.


Do you have just exhaust mans and elbows, or is there also risers?

 

[Bt Doctur]

standard cooling system with no upper hoses
Looking at the diagram your missing the hoses to the riser, not allowing water to exit and cool untill the Tstat is open

 

[Scott06]

standard cooling system with no upper hoses
Looking at the diagram your missing the hoses to the riser, not allowing water to exit and cool untill the Tstat is open

Right would think something is wrong as the check balls feed risers constantly, someone must have mixed and matched parts .

Is there any advantage to warm manifolds vs cold ones with constant flow ?

 

[alldodge]

standard cooling system with no upper hoses
Looking at the diagram your missing the hoses to the riser, not allowing water to exit and cool untill the Tstat is open

There is no upper hoses but has a Tee with check balls?

 

[stang32]

There is no upper hoses but has a Tee with check balls?

yes, the tee allows water from the feed hose to enter the bottom of the manifold and the thermostat housing feeds the expelled warter from the engine once the tstat opens.
there are only elbows, no risers, and the gasket is restricted and it is in correctly.

 

[alldodge]

yes, the tee allows water from the feed hose to enter the bottom of the manifold and the thermostat housing feeds the expelled warter from the engine once the tstat opens.

Guess I'm missing something. The Tee I'm discussing has the check balls which are on top of thermostat and the hoses go the the elbows on each side

Is your cooling system arranged like the one in pic post 6 ?

 

[stang32]

Saying check balls I'm assuming this is you system.
View attachment 365004

Do you have just exhaust mans and elbows, or is there also risers?

no, this is not what i have, the system i have is most like the diagram below, except it does not have 19,20,22,23 and as i said earlier, no water distribution assy, only an elbow which attaches hose 7 and 11 it has a tee fitting, which goes on the bottom ofthe manifolds

 

[stang32]

Guess I'm missing something. The Tee I'm discussing has the check balls which are on top of thermostat and the hoses go the the elbows on each side

Is your cooling system arranged like the one in pic post 6 ?

no dodge, this is a bravo t'stat housing, the check balls are in the tee on the bottom of the manifolds

 

[alldodge]

The piece above is a check ball assembly used on easy drain (3 point) system. Its also used with additional hoses going into the upper elbows. The bottom connections are only used to drain the system, they are not used to flow water thru for cooling.

Your motor came this way from the factory




Someone has gone in and removed some of the items more then likely because the water distribution housing broke. Talked to a boater at my dock yesterday saying he has broken 3 of them.

So that said, it either needs to be changed back to what it was, or change the gaskets to full flow type.



This one is one on one end and restrictor on the other. Water coming up from the Man's the one full flow may be enough. This would help keep both Mans full and elbows with discharge

If you have riser extensions then will need to use full flow type between Mans and risers
https://www.mercruiserparts.com/864547a02-gasket-elbow

 

[QBhoy]

You’ll definitely have a few drain plugs for sure. But anyway…are we sure the impeller hasn’t suffered again and the flappers aren’t missing down the exhaust?
I’d also take the plug out the circ pump housing to see if it’s blowing air and water out there. That would tell you it’s not getting a prime to the impeller raw pump and maybe drawing air somewhere

 

[alldodge]

Have done some more thinking on subject and have to add

You can't get there from here

Reason;
The current thermostat is designed to only allow water thru the Man's when the thermostat opens. Any other time there is very little water going thru. Changing the gaskets will be necessary if the Stat allowed more flow but it will not

To solve the issue and keep one hose each going into each Man is to use the old style 4 port housing.



Change the housing, remove the check valves under the Mans, make sure the Man to Elbow gaskets are correct and your good to go

 

[QBhoy]

Have done some more thinking on subject and have to add

You can't get there from here

Reason;
The current thermostat is designed to only allow water thru the Man's when the thermostat opens. Any other time there is very little water going thru. Changing the gaskets will be necessary if the Stat allowed more flow but it will not

To solve the issue and keep one hose each going into each Man is to use the old style 4 port housing.

View attachment 365036

Change the housing, remove the check valves under the Mans, make sure the Man to Elbow gaskets are correct and your good to go

Good shout there. I commented not realising the most recent info. Really should learn to read the whole post first !!

 

[Scott06]

Have done some more thinking on subject and have to add

You can't get there from here

Reason;
The current thermostat is designed to only allow water thru the Man's when the thermostat opens. Any other time there is very little water going thru. Changing the gaskets will be necessary if the Stat allowed more flow but it will not

To solve the issue and keep one hose each going into each Man is to use the old style 4 port housing.

View attachment 365036

Change the housing, remove the check valves under the Mans, make sure the Man to Elbow gaskets are correct and your good to go

I think he will need a way to get raw water up to the right hand side of this housing , which is different than where it goes now. Certainly not impossible but will take some creative hosing

 

[alldodge]

Should not be a issue if redoing to pre-easy drain. Otherwise needs to reinstall missing parts

 

[stang32]

The piece above is a check ball assembly used on easy drain (3 point) system. Its also used with additional hoses going into the upper elbows. The bottom connections are only used to drain the system, they are not used to flow water thru for cooling.

Your motor came this way from the factory

View attachment 365026


Someone has gone in and removed some of the items more then likely because the water distribution housing broke. Talked to a boater at my dock yesterday saying he has broken 3 of them.

So that said, it either needs to be changed back to what it was, or change the gaskets to full flow type.


View attachment 365027
This one is one on one end and restrictor on the other. Water coming up from the Man's the one full flow may be enough. This would help keep both Mans full and elbows with discharge

If you have riser extensions then will need to use full flow type between Mans and risers
https://www.mercruiserparts.com/864547a02-gasket-elbow

i don't follow, how is changing the gaskets to full flow going to resolve anything when no water comes up at all? if the restiction was the issue, shouldnt i get something?

right now, i have the intermediate elbows disconnected so i can see water, if any, flowing out of the elbows.
with the thermostat installed, no water comes out of the elbows. and the back pressure inside the engine has already caused 2 crimp type hose clamps to pop off.

when there is no thermostat in place, plenty of water flows out of the elbows.

if i reinstall the hoses to the elbows, how do the manifolds cool while the engine is in warm up(thermostat closed)
hmm, now that i am thinking about it, with out the distribution assy, i have no idea how you would drain this system.
i think without reinstalling all the parts missing, i am just going to go around and round.