2004 Mercruiser 6.2 Bravo 3 Still over heating

[hall832]

Overheat alarm coming on. Put on a new impeller.Overheat still. I was getting no water to the raw water pump. Impeller was shredded. I checked the flow to the raw water pump nothing. I tried to back flush it and nothing. I then replaced the impeller, rerouted the water pick up from the bravo three drive(figured i have a collapsed pick up hose) to a through hull. Put it all back together. Started the motor & checked all the peck **** valves on water pump and I have great flow from the pump now. Ran the motor again and a over heat. not sure where to check now. thank you all again for the previous assistance.

 

[Fun Times]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

Are you getting an oberheat while in the water or on the trailer using water hose?

How long before the overheat is noticed?

Do you have good water flow out the exhaust relief ports?

On your intake water hose, is it red in color with a black quick disconnect fittings in the middle and/or at the end of the hose? If so, Make sure it's connected good so you don't suck any air.

Salt water boat?

 

[hall832]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

Salt Water Boat,
Good Water flow,
It takes about 10-15 min to over heat in the water at the dock.
No quick disconnect.

 

[hall832]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

the only thing I can think of is the trans cooler maybe got some of the impeller chunks in it.

 

[Bondo]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

the only thing I can think of is the trans cooler maybe got some of the impeller chunks in it.

Ayuh,... I believe it's Up-stream of the pump, ain't it,..??

Bein' a saltwater boat, pull the risers off the manifolds, 'n see if they're restricted, or plugged up,...

Ya got water goin' in, 'n now it's gonna be able to get Out,...

 

[Fun Times]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

It takes about 10-15 min to over heat in the water at the dock.

That's about the time it would take your thermostat to fully open in normal working conditions at idle speed. Actually 8 minutes seems to be the norm. If it's stuck closed, it could overheat.

When was the last time you check/replaced the thermostat and related parts?

+1 with Bondo at checking the exhaust system.

 

[thumpar]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

You need to figure out where the pieces of shredded impeller went to. When mine did that I pulled the hose from the thermostat housing and put the garden hose from the house in it. I got pieces of rubber flowing out.

 

[JustJason]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

Unless I missed it someplace. Are you freshwater cooled or raw water cooled? As the troubleshooting steps are a bit different between the 2.

Also, it is a slow overheat correct? Takes a few minutes before it gets to hot? Do you have an IR temp gun?

 

[HT32BSX115]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

the only thing I can think of is the trans cooler maybe got some of the impeller chunks in it.

Howdy,

You really don't have a "trans-cooler" per se'.......... You may have an oil cooler AND a separate power steering fluid cooler.....or a combined oil/PS cooler. Most of the oil coolers that Mercury uses have rather small holes for the cooling water.......

A lot of the standard (marine) PS coolers will pass large 'chunks'.

When my oil cooler was clogged with impeller fragments, NO amount of back-flushing would dislodge them. I had to literally pull them out using needle-nose pliers.

You'll likely have to remove the oil cooler to pull the debris out of it.


Regards,



Rick

 

[thumpar]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

You could have a cool fuel system. The rubber can get in there too.

 

[Fun Times]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

FWIW, The way the cool fuel "cooler tube" is designed, debris typically does not get stopped in there as it is an open tube like seen the photo below.

 

[HT32BSX115]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

FWIW, The way the cool fuel "cooler tube" is designed, debris typically does not get stopped in there as it is an open tube like seen the photo below.

Yeah. *some* power steering coolers are like that with a rather large 'hole' inside that will allow debris to pass.......

 

[hall832]

Re: 2004 Mercruiser 6.2 Bravo 3 Still over heating

Pulled the oil cooler, large tube no blockage. I think i at manifold replacement.