Overheating

[alldodge]

This is the best pic I can find
The thermostat top looks OK but appears to be missing the other hose connection down lower which comes from the circulating water pup and would be a small hose

The main circulating water pump hose (large) comes in from the bottom left middle, and exits far left hose going to the exhaust elbows

 

[Jakem]

I pulled my end caps of exhaust manifold as well as elbow and found these

 

[alldodge]

Looks like one was the correct part, but so long as the ends were sealed all is good
27-48043

 

[Jakem]

Alright so took boat out today and it read hot and filled expansion tank...the fluid was not hot I could stick my finger in the heat exchanger without burning myself...if I slowed down and put it into neutral and cracked the cap the expansion tank would drain back in hx...so confused

 

[alldodge]

Water isn't circulating and sounds like a head gasket leak.

Use an IR temp gun or put your hand on top the thermostat housing. If the housing isn't hot then the thermostat is closed. If it is hot, are any of the hoses coming out of the housing warm/hot?

BTW are you in salt water?

 

[Jakem]

I run salt mostly...I've done flush and it was all clean and clear. The hoses are warm yes but never hot. New thermostat 140 degree. New cap..14 psi

 

[alldodge]

Was hoping if you were in fresh I would suggest removing the HX, but ok back to the problem

Can you sketch up a drawing of the hose routing's. Could use the one I posted above and just indicate where its different

 

[Jakem]

I'm not an artist but here it is lol

 

[Jakem]

The hose that has t runs from exhaust elbow...the other is from lower end cap back of manny

 

[alldodge]

Normally the small hose coming from the pump goes to the Man's for main cooling. There is also a small opening to allow AF to bypass the thermostat (TS) so air can escape along with allowing a small amount to pass



With no connection to the TS other then the 2 hoses going to the Mans, would have me wonder if the mans are getting hot as well. Unless there is a hole, the only time the Mans get cooling is when the TS opens

Does the thermostat housing have a hole where AF can bypass the thermostat.

 

[Jakem]

They get pretty warm ya...there's just the 2 man hoses and one smaller going to pump...

 

[Jakem]

What thermostat house would you suggest

 

[alldodge]

Trying to figure something out, but tell me does the current thermostat housing have a by pass hole in it?

I'm thinking if it does we might get away with fixing it like a GM 305

 

[Jakem]

No there isnt

 

[alldodge]

Making it harder, but will see if I can find a housing with a bypass

 

[Jakem]

Thank you for your help

 

[Scott Danforth]

looks like the kit was added after the fact.

 

[Jakem]

I just took the raw water hose off of hx and ran vinegar through it and it drained really slow back out of the system..can't imagine that's normal

 

[alldodge]

Agree

 

[Jakem]

Are these normal...like are the fins going the right way