cooling problems 1.7 DTI (Mercruiser/Cummins)

[hybride]

Hi,

I suffer cooling problems from the beginning. The engine is from 2004 with Alpha one 1 gen 2.
My boat is 6,8 m (Uttern C68). At full speed 4200rpm@46kmh

Above 3600 rpm the engine gets hot, to hot. The temp meter in the dashboard slowly climbs up to the red section. On 4200 rpm it takes about 2 a 3 minutes till it in red.

I allready changes the impeller. It helps a bit for a while.

What can be wrong... Is something wrong or is this normal?
Maybe the pipes in the heat exchanger are closed, but this is hard to check. I have to dissasemble a lot to check that. Anyone got the same experience or has some tips?

[hybride]

I read about someone who has 'bled the coolant line' and solved the problem.

Anybody knows what this means and how to do it exactly?

[Locozodiac]

Originally Posted by hybride

Hi,

I suffer cooling problems from the beginning. The engine is from 2004 with Alpha one 1 gen 2.
My boat is 6,8 m (Uttern C68). At full speed 4200rpm@46kmh

Above 3600 rpm the engine gets hot, to hot. The temp meter in the dashboard slowly climbs up to the red section. On 4200 rpm it takes about 2 a 3 minutes till it in red.

I allready changes the impeller. It helps a bit for a while.

What can be wrong... Is something wrong or is this normal?
Maybe the pipes in the heat exchanger are closed, but this is hard to check. I have to dissasemble a lot to check that. Anyone got the same experience or has some tips?

Have you checked your thermostat ? Does it work properly opens/shut. Change and test.

[Nick Hearne]

Hi I have had the same problem with a Uttern S64 with a 4.3 Lt petrel, all started because when it was got ready for me to collect it was run up on muffs to the Alpha 1 leg!
But this is not conected to the engine for cooling, mine has a through hull inlet for this! So he ran it up & destroyed the inpela for the engine as it received no water. In the end I had a new water pump fitted & anther through hull intake fitted as these are very prone to blocking so if one blocks the other can keep the engine cool.
So if it is fitted as mine your water intake on the leg will be just cooling the leg & not the engine!

Nick

[hybride]

Originally Posted by Nick Hearne

So if it is fitted as mine your water intake on the leg will be just cooling the leg & not the engine!

Nick

Nick, i don't get that?

[Nick Hearne]

Originally Posted by hybride

Nick, i don't get that?

On my boat if I put muffs on the leg to run the boat up out of water this will only cool the leg mot the engine!
The engine is cooled through hole in the hull so it needs to be on the water to run the engine up!
Nick

[nik]

Originally Posted by hybride

Hi,

I suffer cooling problems from the beginning. The engine is from 2004 with Alpha one 1 gen 2.
My boat is 6,8 m (Uttern C68). At full speed 4200rpm@46kmh

Above 3600 rpm the engine gets hot, to hot. The temp meter in the dashboard slowly climbs up to the red section. On 4200 rpm it takes about 2 a 3 minutes till it in red.

I allready changes the impeller. It helps a bit for a while.

What can be wrong... Is something wrong or is this normal?
Maybe the pipes in the heat exchanger are closed, but this is hard to check. I have to dissasemble a lot to check that. Anyone got the same experience or has some tips?

Hi, I have one of these engines and the temperature never goes above 80 degrees c, even when flat out.

Nick.

[simmons0]

ditto, sure your gauge isn't in Fahrenheit?

[hybride]

Today i'll tried to bleed the internal coolant circuit. There was no air in ;(

I'm desperate.. above 3600RPM the fun begins, but not in my case...

The next thing i want to check is the thermostat.
Do these things easily give problems?? Personally think not. What can be wrong with a thermostat?

[nik]

Originally Posted by hybride

The next thing i want to check is the thermostat.
Do these things easily give problems?? Personally think not. What can be wrong with a thermostat?

It could be stuck shut. You could remove it and try running the engine without a thermostat.