Mercruiser 5.0 Bravo 3 closed system

[rick3452]

Just came back from 1 hr Intercoastal cruise (slow speed) Noticed that the temp gauge was over 200 but holding steady. ALWAYS runs at 160, Risers warm/cool to touch.... Should I start with thermostat, or go right to impella? Dont know when the Impella was done.

Thanks!
Rick

 

[Bondo]

Re: Mercruiser 5.0 Bravo 3 closed system

or go right to impella? Dont know when the Impella was done.

Ayuh,... Thay's Always the 1st place to Look....

 

[Don S]

Re: Mercruiser 5.0 Bravo 3 closed system

As mentioned, the impeller is always the first thing you check in an overheat, even brand new impellers don't put up with plastic bags over the intakes. Then, if you shut the engine off, it floats away looking for the next victim.

 

[tpenfield]

Re: Mercruiser 5.0 Bravo 3 closed system

Just came back from 1 hr Intercoastal cruise (slow speed) Noticed that the temp gauge was over 200 but holding steady. ALWAYS runs at 160, Risers warm/cool to touch.... Should I start with thermostat, or go right to impella? Dont know when the Impella was done.

Thanks!
Rick

Impella ?? you sound like you are from Boston

I would check for clogs at/inside the intake on the outdrive, then check the impeller if that does not pan out.

 

[rick3452]

Re: Mercruiser 5.0 Bravo 3 closed system

Ok , I guess I was assuming that on a closed system that the T stat was controling the temp gauge. I thought the impella was running through the manifold and risers.

 

[Bondo]

Re: Mercruiser 5.0 Bravo 3 closed system

Ok , I guess I was assuming that on a closed system that the T stat was controling the temp gauge. I thought the impella was running through the manifold and risers.

Ayuh,.... The coolant is cooled by the water moved by the impeller...

 

[rick3452]

Re: Mercruiser 5.0 Bravo 3 closed system

Ayuh,.... The coolant is cooled by the water moved by the impeller...

now it makes sense! thank you......my plan is to remove the three bolts on the housing and rebuilding... unless you think it would be easier to remove the whole pulley assembly?

0M012817 SER #

 

[Scott Danforth]

Re: Mercruiser 5.0 Bravo 3 closed system

after the impeller change

I would also look at your thermostat and finally your heat exchanger.

if you have run thru muck or sand, picked up crud, etc , you could have fouled the heat exchanger.