Engine temperature warning

[Jimham354]

Hi there, just taken out our boat for the first actual run since being out for the winter. The engine wasn’t used a lot last year or the year before. The engine temperature warning came on after only a short while of cruising. Water is coming out the exhaust as normal but the strainer never fills up, it is empty to start with and then water is sucked up, but it never fills up even the slightest.
Any advice for what could be the problem and some fault finding?

 

[VicS]

What engine? ( Direct seawater cooled or indirect ?)

Pump impeller changed recently ?

Heat exchanger ( if relevant) cleaned recently?

 

[Fr J Hackett]

What engine? ( Direct seawater cooled or indirect ?)

Pump impeller changed recently ?

Heat exchanger ( if relevant) cleaned recently?

I would add blocked strainer / filter.

 

[webcraft]

Check the impellor as the most likely culprit.

Also, get a laser thermometer and check the temperature right beside the temp. sensor, as these can go faulty.

 

[Refueler]

OK ....

Water is exhausting out - showing that impellor is working and water is being drawn in.

But engine temp alarm comes on ...

Water strainer appears not to fill ....

mmmmmm

OK ...

1. If there is a thermostat - it may be stuck closed - forcing water to exit via bypass to exhaust instead of through engine cooling channels or Heat exchanger. Check thermostat. Some engines if you take out Thermostat - if the water flow has insufficient pressure - will exit via bypass and not enough through engine channels or HE. My Perkins has thermostat removed - but I have a large water volume flow so it doesn't matter.

2. Alarm may be faulty ... as another says - get a Laser therm and check ..

3. Water flow may be high enough that strainer actually does not fill .... my Yanmar 2GM has a large pot strainer and that basically looks empty when engines running - the water is flowing though ..

Just thoughts.

 

[gregcope]

Assuming indirect cooled - Coolant levels or water pump? If belt driven, belt tension?

The HE should be warm but not hot to touch if sufficient sea water is going through it.

 

[Refueler]

Guys .... I read replies and it seems the fact that water is being exhausted seems to be ignored .... if water is being exhausted sufficiently - then it would be the route the water takes that is the problem surely ??

 

[VicS]

Guys .... I read replies and it seems the fact that water is being exhausted seems to be ignored .... if water is being exhausted sufficiently - then it would be the route the water takes that is the problem surely ??

Until the OP tells us what engine and, in particular, if it is direct or indirectly cooled it is impossible to give any meaningful advice apart from a few general points already made.
.

 

[Refueler]

Until the OP tells us what engine and, in particular, if it is direct or indirectly cooled it is impossible to give any meaningful advice apart from a few general points already made.
.

Agreed - but when you read stuff like check impellor / pump - you begin to wonder if people read the OP's info.

 

[MAURICE]

if direct water cooled than possible that some of the water ways are blocked so the salt water is not circulating properly around the engine causing a hot spot.
if indirect water cooled it could also be the same problem and also the fresh water pump not working
As said there seems to be enough salt water coming out the exhaust so check water level of fresh water and when the engine is cold check that the fresh water is circulating

 

[Refueler]

if direct water cooled than possible that some of the water ways are blocked so the salt water is not circulating properly around the engine causing a hot spot.
if indirect water cooled it could also be the same problem and also the fresh water pump not working
As said there seems to be enough salt water coming out the exhaust so check water level of fresh water and when the engine is cold check that the fresh water is circulating

I'm putting my money on thermostat stuck closed and water is flowing via bypass .... but we don't know.