mec.6.2 over heating (05)

[k4ubr]

i have an 6.2 mpi (2005) dry joint exhaust,seawater cooled. The STBR MANIFOLD runs 100 degrees hotter than the port . it will over heat the motor after about 10mins, on the water. ran motor check all temps with heat gun , on run up the risers heat up together but the stbr. stays at 200. wile the port comes down to 115--- back at idle, it takes about 10min. to drop 20 degrees. i have replaced, the seawater pump (assy) and 3 t-stats, headgaskets-2, stbr. manifold-riser new from MERC. and all plugs rotor and cap.
it seems the water is not leaving the manifold. the old manifold. did the same thing.. this is why i replaced the hole seawater pump. motor runs good. also i removed a broken flapper from the exhaust passage. for sure that was it,no dice.... all the same with no t-stat

 

[Bt Doctur]

Re: mec.6.2 over heating (05)

Thermostat housing itself?
What about the hose that goes to from the therm hsng to the manifold, if it was damaged internally it might restrict the flow, try swapping hoses and see if the other manifold gets hot.

 

[k4ubr]

Re: mec.6.2 over heating (05)

ill check the hose idea for shure , the check valves at the bottom of the manifold can thy cause this problem?

 

[JustJason]

Re: mec.6.2 over heating (05)

have you pulled the exhaust manifold yet and looked at it?

 

[Zackman]

Re: mec.6.2 over heating (05)

Wow, 200 F that's way too hot...

You may want to try something... Go to the Home Depot or similar and get 2 two foot length of the clear reinforced hose (high temperature), I think its 1-1/2" diameter (same id as your current hose). Temporarily remove the water hoses from the thermostat housing to the mainfolds and install the clear hose. Take her out with the IR gun and check the flow and temp to each manifold.

Have you ever lost a piece of the raw water pump impeller that you couldn't find?​

 

[k4ubr]

Re: mec.6.2 over heating (05)

yes too the impeller blade( NEVER FOND) ???????????? i have not removed the manifold yet. this is a new one just installed. the old set up did the same thing. this is a BROVO 3 175HRS. SALTWATER IT ALSO HAS NEW HEAD GASKETS I HAVE BEEN THRUOGH THE 31 MANUL . I HAD A CASTING PROBLEM ON A NEW POWERHEAD FROM EVINRUDE IN 98 .