Mercruiser 5.0 MPI Bravo 3 overheat 5 minutes after starting it up.

[Bravo402]

I'd be looking at them anyway before moving forward.
well over 15 yrs old ...
Michigan Motors has the stuff, If ya need them ,great folks

while I got the backseat out and plenty of room. Now the time to get it all done. Thanks for the tip I will look them up now. Should I go with oem or aftermarket ones good?

 

[alldodge]

Fresh water mans will outlast the boat. Sold ones I took off my 94 Formula during repower and they looked great

 

[Bravo402]

Fresh water mans will outlast the boat. Sold ones I took off my 94 Formula during repower and they looked great

Dang I didn’t think they would last that long.

 

[DS_G]

have good flow everywhere. Just checked new thermostat in water and it’s opening. Still overheating. I have no idea on this one.

Look up this post

Mercruiser 6.2 MPI Bravo 3 overheating​

 

[DS_G]

Is it possible the manifolds and risers need replacing? The manifolds and risers are the originals that came with the boat I believe. Boat has never been in salt water. The original owner let the boat sit on the trailer for several years before I purchased it.

Yes. See

Mercruiser 6.2 MPI Bravo 3 overheating​

 

[alldodge]

Yes, post 9

 

[Bravo402]

Update on the boat:
Just got back from the lake.
I didn’t take it out on the water I kept the boat on the trailer. After replacing the circulation pump. Let it run for close to 15 minutes.
Temp got up a little past 170. One manifold is a little hotter than the other. The risers are cold to the touch. Not sure on the temp. as I forgot to bring the IR gun. Going to be a wash out here this weekend with rain coming in from the depression that’s hitting New Orleans right now. Soon as weather allows will post another update.

 

[Bravo402]

Yes. See

Mercruiser 6.2 MPI Bravo 3 overheating​

I did. Thanks for helping me and everyone I really appreciate all the help. Definitely helps. I got gaskets on order for when I check this.

 

[Bravo402]

Well the news is not good. Believe we have a blown head gasket on the starboard side. Got water in the oil. The IR on port reading 150 and on the starboard side reading around 185.