cooling problems 1.7 DTI (Mercruiser/Cummins)

hybride · 21 April 2008, 16:20

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 · 21 April 2008, 17:48

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 · 21 April 2008, 22:27

Quote:

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 · 22 April 2008, 16:33

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 · 23 April 2008, 19:11

Quote:

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 · 24 April 2008, 15:41

Quote:

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 · 25 April 2008, 10:05

Quote:

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 · 26 April 2008, 02:30

ditto, sure your gauge isn't in Fahrenheit?

hybride · 26 April 2008, 18:17

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 · 27 April 2008, 12:26

Quote:

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.

Alex-341 · 02 May 2008, 21:14

Remove the thermostat and put it in some pretty hot water, if it moves, its fine. If not or it moves very slowly then that could be the source of your problem.

Daveboy 71 · 02 May 2008, 21:32

1. Check thermostat (remove as stated) or replace (quite cheap).
2. Check guage - is this reading correctly (I had a temp guage fail in a car and it tended to read hot when the engine was in fact at normal operating temperature)?
3. If cooling is okay and guage is correct then you may have a genuine problem with the engine. One possible cause is cylinder head gasket failure. Alternatively you may have a mixture problem.

hybride · 09 May 2008, 22:25

hi all, thx for helping

Today i removed the thermostat. The overheat problem is less, but not gone.
It takes a longer time now untill the temp meter is going in red.
How can i measure the real temperature?

I have a strange propellor. 18d-16P Maybe i should try a 15d-17p.
But an expert says that another prop will not influence motor temp

I am know working on a idea to put a little radiator with fan in the closed cooling circuit.
Its quiet easy to do that (as i suppose now)

IanE · 13 May 2008, 10:09

this link may be of interest. http://groups.yahoo.com/group/cummin...ser_120hp_DTI/

Ian

hybride · 13 May 2008, 15:59

thx. I allready am a member there.

I seem to be the only one suffering heat problems...

hybride · 21 June 2008, 07:59

Heat problem solved!

What i did is remove the heatexchanger cap on the front off the
motorblock. 3/4 of the heatpipes where filled with
little 'shell-powder'!!

I bought a 4 mm long metal ash and pushed it through the holes.
After that i flushed the system with fresh water to get rid of the shells.

I fixed this in about 1,5 hour. I hope this will help more people. I
think to do it better every year.

p.s. do you see the three blowers on top? :-)
Did this earlier to get fresh airflow (and cooling)

Rogue Wave · 21 June 2008, 08:37

you been running in shallow or silted water?

hybride · 21 June 2008, 10:04

Quote:

Originally Posted by Rogue Wave

you been running in shallow or silted water?

Mostly at a lake with a dept of 1 to 3 meter with sandy bottom.
What you see on the picture is the inheritance from 4 years.
What you don't see at the picture (just forgot) is the picture of the lid (cap?)
This was also 50% filled with permanently grown shells.

Boat is from 2004 and it lies summer and winter in the water.

I am now working on a idea to make it possibility to easily flush the heat exchanger with sweet water from inside the boat.
Later more.

dwlewis · 17 October 2008, 19:31

Antonin/members.
I have an overheating problem on a cummins 1.7 used in a Uttern S64 exactle as described. ( Overheating at higher revs )
What have you Guy's done to resolve this problem ?