Leyland 4/98 engine is overheating - any suggestions??

[santiago]

Thank you for all your helpful suggestions. Francois will be back working on the engine tomorrow and we will go through all of them. We have a replacement thermostat and so will test that and restore it to the engine.

Fowler Man - Can you advise what is the operating temperature of an engine such as ours at say 1,000 rpm or 1,500 rpm. When you mentioned that the thermostat operates at 85 degrees Francois began wondering if he is worrying about an overheating engine that is not overheating at all. The engine used to heat to about 80 degrees at 1,000 rpm, but now it is exceeding that at 800 rpm going up to 90 degrees - but then the weather is boiling hot here most of the time.

Essexpete - engine is mounted on bolts that have been sunk into the concrete keel - there are no flexible engine mounts. I suggested that we might be able to find some kind of flexible interface between concrete, bolt and engine?

Caribbean cruise? The boat's only 36 ft - but we could take you out on day trips!!

[FOWLER MAN]

Hi,
I have no speciffic information on the 4/98 but generaly safe running temprature ranges are up to 98 deg C (210F). Allmost boiling point.
I suppose thats why the boiling point is raised by pressurising the system.
I would expect your engine to run at about 85 to 88 deg.C ,(185 to 190F), may be a little hotter in a warm climate.
Fred

[Kenham]

Hello, as Fowler Man has stated the cooling water will take the route of least resistance and I am thinking it might be pumping more water around the gearbox cooler than the engine cooler. It might be worth trying to restrict the flow in the gearbox cooling pipe to let more cooling water flow through the engine side. A smaller pipe might just do the trick. It is obvious one of us must travel out to inspect the problem. Ken

[essexpete]

Hello, as Fowler Man has stated the cooling water will take the route of least resistance and I am thinking it might be pumping more water around the gearbox cooler than the engine cooler. It might be worth trying to restrict the flow in the gearbox cooling pipe to let more cooling water flow through the engine side. A smaller pipe might just do the trick. It is obvious one of us must travel out to inspect the problem. Ken

Get the coktails ready!

[modelman093]

Thank you for all your helpful suggestions. Francois will be back working on the engine tomorrow and we will go through all of them. We have a replacement thermostat and so will test that and restore it to the engine.


Essexpete - engine is mounted on bolts that have been sunk into the concrete keel - there are no flexible engine mounts. I suggested that we might be able to find some kind of flexible interface between concrete, bolt and engine?

C!!

Suggest not if that is how it was originally as introducing flex there would possibly cause trouble further down the line, eg between the transmission and the prop shaft. Assuming that at some point it did not vibrate can you identify any changes/work done that coincided with the start of the vibration - or has it always vibrated in your ownership?

[santiago]

Hello Happy Helpers - I would dearly love for one/all of you to visit to fix the problem well oiled with rum cocktails but alas 8,000km is quite a long way.

Modelman093 - the cooling set up when we bought the boat was the sea water cooled the gearbox first and then the engine via a single circuit. The water intended to cool the engine was already hot after doing its work on the gearbox. So francois split the water into two pipes and it is only the pipe exiting the engine that appears to have very hot water in it. So now your suggestion of restricting the flow to the gear box might help.

Didn't get much of a look at the engine today as we were off finding the man who can fix alternators, but tomorrow will be an engine day.

Essexpete - as you suggest we won't try to change the engine set up. but the engine has always vibrated since we bought the boat at 1200-1400 revs. It is not the original engine. Haven't had a chance to see if the vibration happens both in and out of gear but will let you know the result as soon as we have.

Will keep you posted and many many thanks again.

[tamarisk1979]

Hi everybody new here... but not new to engine problems worst luck.
In the event you havent solved your problem... I suggest you do a pressure test? you could well have a minor leak from a cylinder into the water jacket... this will cause overheating very quickly... and as in your application there is no radiator you would not notice any gas bubbles coming out of the return water.?
Perhaps you could set up a water return riser box , meaning feed the return water line into the base of say a bucket or even just into a large bucket then if the water has air/gas bubbles coming off the surface, then you know you have a leaking head gasket or something similar... cheers don from downunder