5.0 mercruiser 04 OM696715

cxz200

Cadet
Joined
Aug 15, 2024
Messages
7
Had manifold off left side put back on with new gasket now it ru s hot at idel temp gauge is moving rapidly and I got a ignition fault alarm e ery few minutes had none of this prior have flushed every thing new 160 t Stat new impeller in foot new plugs cap button iam lost
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,431
Had manifold off left side put back on with new gasket now it ru s hot at idel temp gauge is moving rapidly and I got a ignition fault alarm e ery few minutes had none of this prior have flushed every thing new 160 t Stat new impeller in foot new plugs cap button iam lost
Did you use the right gasket between manifold and elbow? Some are restrictor some open depending on if you have warm or cold manifolds.

Would verify thermostat actually opens at 160, and check impeller is on correct and water tube between lower and upper is correctly in place.

Did you use an OEM impeller and was water dam in lower not corroded? Some of the aftermarket impellers are chit, doubel check gaskets and o rings on impeller
 

cxz200

Cadet
Joined
Aug 15, 2024
Messages
7
Did you use the right gasket between manifold and elbow? Some are restrictor some open depending on if you have warm or cold manifolds.

Would verify thermostat actually opens at 160, and check impeller is on correct and water tube between lower and upper is correctly in place.

Did you use an OEM impeller and was water dam in lower not corroded? Some of the aftermarket impellers are chit, doubel check gaskets and o rings on impeller
I used all quick silver parts I had that manifold off but not out it was laying all kind of ways in there I just read that a ball valve could be stuck in the bottom and letting all rhe water go to manifold and not hold it back on the engine wich would make sence manifold is cold t Stat is hot
 

cxz200

Cadet
Joined
Aug 15, 2024
Messages
7
I used all quick silver parts I had that manifold off but not out it was laying all kind of ways in there I just read that a ball valve could be stuck in the bottom and letting all rhe water go to manifold and not hold it back on the engine wich would make sence manifold is cold t Stat is hot
Thanks for help is driving me crazy
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,431
I used all quick silver parts I had that manifold off but not out it was laying all kind of ways in there I just read that a ball valve could be stuck in the bottom and letting all rhe water go to manifold and not hold it back on the engine wich would make sence manifold is cold t Stat is hot
there are check balls in a T on the top of thermostat housing on some mercruisers. This is for the warm manifold style where the manifold and elbow are fed by separate cooling lines. the one that goes to elbow has constant cold water flow regardless of thermostat being open or closed. If it send too much incoming cooling water to elbow it starves engine of cooling water.

At this point double check the gaskets between manifold and elbow, thermostat, verify water flow from outdrive at thermostat. I think the test merc has is take the hose off from outdrive - it will be the 1.25" or so hose on RH side of thermostat housing that lays on top of intake manifold. it should supply 3-4 qts in 15 seconds/3-4 gal per minute or so.

Was the old impeller missing any pieces?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,056
Talking a 160* Stat I'll assume raw water cooled
Do you have a 3 point or 7 point drain system? The 3 point has a lot of hoses connected below motor up front
 

cxz200

Cadet
Joined
Aug 15, 2024
Messages
7
there are check balls in a T on the top of thermostat housing on some mercruisers. This is for the warm manifold style where the manifold and elbow are fed by separate cooling lines. the one that goes to elbow has constant cold water flow regardless of thermostat being open or closed. If it send too much incoming cooling water to elbow it starves engine of cooling water.

At this point double check the gaskets between manifold and elbow, thermostat, verify water flow from outdrive at thermostat. I think the test merc has is take the hose off from outdrive - it will be the 1.25" or so hose on RH side of thermostat housing that lays on top of intake manifold. it should supply 3-4 qts in 15 seconds/3-4 gal per minute or so.

Was the old impeller missing any pieces?
No sir looked new
 

cxz200

Cadet
Joined
Aug 15, 2024
Messages
7
What else has happen since all this now when I start it I have a ignition fault alarm every 2 minutes didn't have that befor eather it was cutting out at higher rpm is all was wrong when all this happen no heating issues till I took off manifold have pulled it off twice double check gasket placement got a diagram from marina I have one restricted hole othe three open have restricted hole on top under water inlet hose
 
Top