Any Perkins mechanics for advice

Neptune 19

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Hi I have a single perkins 4236 M90 the engine is overheating even on low revs it stays at 100. I put new impeller in still same. I found the fresh water inlet to be blocked I cleaned it out still no improvement. when I start the engine and leave the heather tank cap off im getting back blow from the coolant. is this a head gasket problem or is their something else I can try. If it is head gasket have you got a rough price. Thanks for any advice.
 

38mess

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Hi I have a single perkins 4236 M90 the engine is overheating even on low revs it stays at 100. I put new impeller in still same. I found the fresh water inlet to be blocked I cleaned it out still no improvement. when I start the engine and leave the heather tank cap off im getting back blow from the coolant. is this a head gasket problem or is their something else I can try. If it is head gasket have you got a rough price. Thanks for any advice.
Is that 100f? If so I would say it's fine. Are you getting blowback with the coolant cap on through the overflow pipe? Have you a white sludge in the coolant tank? Any sign of oily presence in the coolant.
 

Neptune 19

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Is that 100f? If so I would say it's fine. Are you getting blowback with the coolant cap on through the overflow pipe? Have you a white sludge in the coolant tank? Any sign of oily presence in the coolant.
yeah theres small amount of oil floating on the top of it
 

Rappey

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I do beg your pardon, but I need to check this. I'm pretty sure it's 40c
If its seawater cooled then it will run around 60c or less (cant remember the exact figures) as salt water starts to crystalises above 60C ?
Fresh water cooled runs around 88c.
 

38mess

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If its seawater cooled then it will run around 60c or less (cant remember the exact figures) as salt water starts to crystalises above 60C ?
Fresh water cooled runs around 88c.
It's fresh water cooled, I sit in front of the temperature gauge 12 hours a day before the lockdown and I can't remember. I'll nip down the boat tomorrow, I have a little white paint mark on the correct temperature
 

Rappey

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If it is only running at 40c then it could have a failed thermostat or not even got one?
And my appologies to Neptune19 for running a little off his topic .
 
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