Hi all, looking for answers to the below issue affecting my first ever boat, recent owner.
Volvo Penta 3.0 GLP-D, 4-cylinder, sterndrive, petrol engine on a Glastron 5.2 m fiberglass boat.
Engine runs OK, warming up to ~175 F in ~10 minutes, and will run at this temperature.
Top J-hose, from engine circulation pump to thermostat housing becomes stiff, like a tennis ball. Occasionally, this hose would split due to the pressure.
I'll do a 40 km trip with the recommended 3200 RPM, all good, then next day it will split after 10 minutes. No overheating, still ~175 F, only pressure.
The hose on the other side of the thermostat, going to the manifold is of a thicker material and smaller diameter, difficult to gauge how pressurized it is.
If I remove this hose from thermostat to manifold, then the J hose from engine circulation pump to thermostat is not pressurized any more. As soon as I replace the thermostat to manifold hose, the J hose from engine circulation pump to thermostat is again pressurized. This J hose is warm, ~running temperature of ~170 F. A color diagram I've seen seems to indicate this hose should be cool, if I interpret this correctly. Should this J hose be cool even after warm up, what are the possible causes of it being hot in my case?
I have an exhaust riser extension - manifold + riser extension + elbow. Both the extension and elbow have four slots for the water circulation, however there is a restrictor plate on top of the extension, that is, between the extension and elbow.
All slots with fair bit of residue & clogging. Based on previous owner's service receipts, manifold and riser were replaced 3 years ago.
The position of the slot on the restrictor plate is on the side closest to the engine.
What are some of the paths I should take to try to solve this issue:
1. Replace manifold and riser as it is, with restrictor plate.
2. Clean riser extension and elbow and try to run engine without restrictor plate - observe operating temperature.
3. Clean riser extension and elbow and try to run engine with restrictor plate
Thank you for your help, and apologies if something doesn't make sense in my description.
Volvo Penta 3.0 GLP-D, 4-cylinder, sterndrive, petrol engine on a Glastron 5.2 m fiberglass boat.
Engine runs OK, warming up to ~175 F in ~10 minutes, and will run at this temperature.
Top J-hose, from engine circulation pump to thermostat housing becomes stiff, like a tennis ball. Occasionally, this hose would split due to the pressure.
I'll do a 40 km trip with the recommended 3200 RPM, all good, then next day it will split after 10 minutes. No overheating, still ~175 F, only pressure.
The hose on the other side of the thermostat, going to the manifold is of a thicker material and smaller diameter, difficult to gauge how pressurized it is.
If I remove this hose from thermostat to manifold, then the J hose from engine circulation pump to thermostat is not pressurized any more. As soon as I replace the thermostat to manifold hose, the J hose from engine circulation pump to thermostat is again pressurized. This J hose is warm, ~running temperature of ~170 F. A color diagram I've seen seems to indicate this hose should be cool, if I interpret this correctly. Should this J hose be cool even after warm up, what are the possible causes of it being hot in my case?
I have an exhaust riser extension - manifold + riser extension + elbow. Both the extension and elbow have four slots for the water circulation, however there is a restrictor plate on top of the extension, that is, between the extension and elbow.
All slots with fair bit of residue & clogging. Based on previous owner's service receipts, manifold and riser were replaced 3 years ago.
The position of the slot on the restrictor plate is on the side closest to the engine.
What are some of the paths I should take to try to solve this issue:
1. Replace manifold and riser as it is, with restrictor plate.
2. Clean riser extension and elbow and try to run engine without restrictor plate - observe operating temperature.
3. Clean riser extension and elbow and try to run engine with restrictor plate
Thank you for your help, and apologies if something doesn't make sense in my description.
