Do all 496's have water pressure sensors ?
07-08-2016 | 07:05 AM
#21
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From: Florence, Kentucky
I don't see where you said you're down or up on water pressure. How's that gauge looking and what pressures are you seeing. Too little and too much pressure are signs of flow issues.
Low - potential bad housing
High - still have a blockage issue
If the water dump system had a leak it would be sucking air and you'd lose your siphon and/or be dumping water in the bilge as mentioned.
A friend made a tool for me to back flush from the exchanger. Water pressure alone won't clear debris from the oil cooler. It's the only cooler that is not pass through. It has a honeycomb input. If you can't get to it directly (below port manifold) add some air to the back flush. My tool has air integrated into it. Water and then a burst of air and repeat.
The additional debris removed by adding air was staggering. All temps and pressures returned to normal. I don't have strainers. I've been fighting this for three seasons and finally have a resolution with not having strainers.
Low - potential bad housing
High - still have a blockage issue
If the water dump system had a leak it would be sucking air and you'd lose your siphon and/or be dumping water in the bilge as mentioned.
A friend made a tool for me to back flush from the exchanger. Water pressure alone won't clear debris from the oil cooler. It's the only cooler that is not pass through. It has a honeycomb input. If you can't get to it directly (below port manifold) add some air to the back flush. My tool has air integrated into it. Water and then a burst of air and repeat.
The additional debris removed by adding air was staggering. All temps and pressures returned to normal. I don't have strainers. I've been fighting this for three seasons and finally have a resolution with not having strainers.
07-08-2016 | 07:30 AM
#22
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From: N.E.
Are you getting any water in the bilge when running?
I think BUP is referring to the air actuators that allow water to pour out when you apply air to the schraeder valve (to light-winterize). They have springs in them that can and do go bad over time, and will allow water to pour out of them at higher RPMs. This could be your issue as well.
Also, do you have a fresh water flush system hooked up? Are there any valves, check-balls, or any points where debris could be stopped up in that section of inlet hose from the transom to the SWP?
I think BUP is referring to the air actuators that allow water to pour out when you apply air to the schraeder valve (to light-winterize). They have springs in them that can and do go bad over time, and will allow water to pour out of them at higher RPMs. This could be your issue as well.
Also, do you have a fresh water flush system hooked up? Are there any valves, check-balls, or any points where debris could be stopped up in that section of inlet hose from the transom to the SWP?
just an example but not your exact serial number run but earlier versions - you should have a one piece that could have the check ball - we call them check valves and or check balls.
in the pic number 28 and 29 just an example as again you could have the 1 piece version.
http://www.marineengine.com/parts/me...lbow-and-riser
and yes as Brian said make sure your air actuators are not leaking water - the one behind the water impeller housing if it leaks will surely reduce water flow and reduce water flow to the impeller housing.
in the pic number 28 and 29 just an example as again you could have the 1 piece version.
http://www.marineengine.com/parts/me...lbow-and-riser
and yes as Brian said make sure your air actuators are not leaking water - the one behind the water impeller housing if it leaks will surely reduce water flow and reduce water flow to the impeller housing.
I don't see where you said you're down or up on water pressure. How's that gauge looking and what pressures are you seeing. Too little and too much pressure are signs of flow issues.
Low - potential bad housing
High - still have a blockage issue
If the water dump system had a leak it would be sucking air and you'd lose your siphon and/or be dumping water in the bilge as mentioned.
A friend made a tool for me to back flush from the exchanger. Water pressure alone won't clear debris from the oil cooler. It's the only cooler that is not pass through. It has a honeycomb input. If you can't get to it directly (below port manifold) add some air to the back flush. My tool has air integrated into it. Water and then a burst of air and repeat.
The additional debris removed by adding air was staggering. All temps and pressures returned to normal. I don't have strainers. I've been fighting this for three seasons and finally have a resolution with not having strainers.
Low - potential bad housing
High - still have a blockage issue
If the water dump system had a leak it would be sucking air and you'd lose your siphon and/or be dumping water in the bilge as mentioned.
A friend made a tool for me to back flush from the exchanger. Water pressure alone won't clear debris from the oil cooler. It's the only cooler that is not pass through. It has a honeycomb input. If you can't get to it directly (below port manifold) add some air to the back flush. My tool has air integrated into it. Water and then a burst of air and repeat.
The additional debris removed by adding air was staggering. All temps and pressures returned to normal. I don't have strainers. I've been fighting this for three seasons and finally have a resolution with not having strainers.
Thanks for the tips on the backflush.
07-08-2016 | 08:56 AM
#23
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From: Delray Beach, FL
If the engine is stock than 200 degrees is really concerning and honestly should be addressed if truly accurate. The waning horn should be sounding off right around 196 degrees I believe this one to be preprogrammed at within the ECM as Merc has a few temperature ranges for the waning horn.
In the following link, sensor item number 7 is what the PCM reads for engine temp while sender item numbers 8 is for the temp gauge, http://www.marineengine.com/parts/me...ter-components
In the following link, sensor item number 7 is what the PCM reads for engine temp while sender item numbers 8 is for the temp gauge, http://www.marineengine.com/parts/me...ter-components
07-09-2016 | 11:29 PM
#24
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From: N.E.
Ok, so the only parameter the rinda shows is "Block Pressure". That value is 1.9 at idle and 5.8 at 3800 rpms. My other motor which is running the normal 167 degrees, that block pressure reads 1.9 at idle and 13 at 3800 rpms.
So what sensor is the Block Pressure value reading on the Rinda ?
So what sensor is the Block Pressure value reading on the Rinda ?
07-10-2016 | 08:37 AM
#26
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From: Tygart Lake, WV
07-10-2016 | 08:55 AM
#27
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From: N.E.
So will a new Hardin pump solve this ? Or could there still be a restriction somewhere before the pump...like the gimbal hose. Boat is kept in the water and i can't really backflush through the drive.
07-10-2016 | 10:49 AM
#28
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From: Mass
Pull the water pump and take a look at the condition since that is an easy one to do. The mud may have done a number on the impeller and housing. Any type of scoring on the housing will cause pressure problems. If the pump and impeller check out, then you have issues in the fresh water side of things.
07-10-2016 | 12:31 PM
#29
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From: Ft. Worth TX
the drop in repair kit for the original housings are a bandaid anyways. Many people forget that the sides of the housing wear and scars as well.. Impeller housings and impellers are matched to certain tolerances to pump the correct water flow volume and maintain pressure thru all rpms. These tolerances are matched front and back along with the complete side walls of the impeller housing.
Also boat owners who do not winterized properly and or do not drain the impeller housing 100 % of water risk a change of distorting the impeller housing in freezing temps.
Also boat owners who do not winterized properly and or do not drain the impeller housing 100 % of water risk a change of distorting the impeller housing in freezing temps.
Last edited by BUP; 07-10-2016 at 12:34 PM.
07-10-2016 | 02:18 PM
#30
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From: Delray Beach, FL
Does Hardin have a pump for the 496 with the water pressure sensor hole? I know they have one for the 502... and 496 without the sensor.
Last edited by Keith Atlanta; 07-10-2016 at 02:24 PM.
