575 sci Back Flushing Method - Need Advice
06-03-2014, 07:41 AM
#23
This is very good info. Thank you for posting about the fuel cooler. I knew is was a tube style cooler from the parts fiche, but couldn't get anything in there to confirm if it was open or honeycomb grid style.
My oil cooler had some minor blockage, but nothing extreme - both it and the PS cooler are now confirmed clear.
My oil cooler had some minor blockage, but nothing extreme - both it and the PS cooler are now confirmed clear.
The fuel cooler, which I have had off many times is pretty much wide open. The return line runs down the back side, the cooler has an inductive plate to cool the fuel and pump, they are not connected as one. Very simple, and it wont even stop impeller pieces, mine always make it up to the oil cooler which I just remove the end cap to clear.
Have you tried switching the lines on the back of the gauges to see if it is a gauge problem? I also agree with cleaning the lines and ports, they clog easy. Hit them with air at the gauge, then remove from block and drain block.
Have you tried switching the lines on the back of the gauges to see if it is a gauge problem? I also agree with cleaning the lines and ports, they clog easy. Hit them with air at the gauge, then remove from block and drain block.
06-03-2014, 10:27 AM
#24
Registered
#4 and 5 go on both sides of the housing with the long bolt to hold them.
http://www.mercruiserparts.com/Show_...mostat+Housing
06-03-2014, 01:02 PM
#25
VIP Member
Yes, to clarify, I was talking about the FRESH WATER FLUSH system that some boats have, with a spring/checkball built into the Tee, that the garden hose attaches to for flushing.
My mistake in that I confused the thermostat housing with flush water attachment system. (I missed the word 'thermostat' originally.)
My mistake in that I confused the thermostat housing with flush water attachment system. (I missed the word 'thermostat' originally.)
06-03-2014, 02:55 PM
#27
I did not swap the gauge (yet). I am suffering from low water pressure and rising water/oil temps during a short 1/2 ~ 3/4 throttle run. At a cruise speed of 3200 rpm, all temps in check - and we usually rus between 3200~ 3700 rpm - this results in about 4psi on the water pressure gauge. However, when I feel like running a faster engine speed, water pressure lowers and water/temp starts to increase. Therefore, what I'm seeing on water pressure seems to be in direct correlation to what I'm seeing on water/oil temp - thus I've ruled out the water pressure gauge.
Based on what I've read and heard from other Fountain owners, I should see north of 15~20 psi when running at cruise speed.
Based on what I've read and heard from other Fountain owners, I should see north of 15~20 psi when running at cruise speed.
06-04-2014, 08:55 AM
#28
Well, I learned a couple of things last night while continuing to troubleshoot.
I believe the intake hose is past due for a change - it's highly worn at the sea pump end. If the inside is as bad as outside, then it could be sucking it closed under high rpm. As long as I get the hose off the transom water neck! Its pretty far down to get a good grip on it (blowers/fuel injection in the way). Won't hurt anything to change it though.
[ATTACH=CONFIG]524228[/ATTACH]
I hooked an electric water pump motor to the inlet of the first cooler (fuel cooler). Water ran freely and in large volume from the exit of the fuel cooler. So I believe it is wide open and not clogged. I also checked for same flow at the exit of the power steering cooler. It too ran freely with large volume. So that confirms that my oil cooler and power steering coolers are still free (I removed both of them last week to confirm by eye that they are clear). Then I checked at the large hose on the thermostat housing and still, water was free and in large volume.
[ATTACH=CONFIG]524230[/ATTACH]
Next, I was able to reach the hose clamps on the intake hose at transom water neck. I was able to turn both clamp screws about 2 full turns. I'm not sure if this is enough to induce an air leak, but could be??? I've noticed no water leaking at this connection, however.
Lastly, I checked the nylon balls and springs in the thermostat housing (thought I'd been in there before, but I was mistaken). They were very loose, and springs were worn out. Based on water flow diagram, I'm not sure how this would control block water pressure - but they need to be replaced, so that will happen hopefully this week).
[ATTACH=CONFIG]524231[/ATTACH] [ATTACH=CONFIG]524232[/ATTACH]
Thoughts?
I believe the intake hose is past due for a change - it's highly worn at the sea pump end. If the inside is as bad as outside, then it could be sucking it closed under high rpm. As long as I get the hose off the transom water neck! Its pretty far down to get a good grip on it (blowers/fuel injection in the way). Won't hurt anything to change it though.
[ATTACH=CONFIG]524228[/ATTACH]
I hooked an electric water pump motor to the inlet of the first cooler (fuel cooler). Water ran freely and in large volume from the exit of the fuel cooler. So I believe it is wide open and not clogged. I also checked for same flow at the exit of the power steering cooler. It too ran freely with large volume. So that confirms that my oil cooler and power steering coolers are still free (I removed both of them last week to confirm by eye that they are clear). Then I checked at the large hose on the thermostat housing and still, water was free and in large volume.
[ATTACH=CONFIG]524230[/ATTACH]
Next, I was able to reach the hose clamps on the intake hose at transom water neck. I was able to turn both clamp screws about 2 full turns. I'm not sure if this is enough to induce an air leak, but could be??? I've noticed no water leaking at this connection, however.
Lastly, I checked the nylon balls and springs in the thermostat housing (thought I'd been in there before, but I was mistaken). They were very loose, and springs were worn out. Based on water flow diagram, I'm not sure how this would control block water pressure - but they need to be replaced, so that will happen hopefully this week).
[ATTACH=CONFIG]524231[/ATTACH] [ATTACH=CONFIG]524232[/ATTACH]
Thoughts?
06-04-2014, 09:27 AM
#29
Registered
iTrader: (4)
Well, I learned a couple of things last night while continuing to troubleshoot.
I believe the intake hose is past due for a change - it's highly worn at the sea pump end. If the inside is as bad as outside, then it could be sucking it closed under high rpm. As long as I get the hose off the transom water neck! Its pretty far down to get a good grip on it (blowers/fuel injection in the way). Won't hurt anything to change it though.
[ATTACH=CONFIG]524228[/ATTACH]
I hooked an electric water pump motor to the inlet of the first cooler (fuel cooler). Water ran freely and in large volume from the exit of the fuel cooler. So I believe it is wide open and not clogged. I also checked for same flow at the exit of the power steering cooler. It too ran freely with large volume. So that confirms that my oil cooler and power steering coolers are still free (I removed both of them last week to confirm by eye that they are clear). Then I checked at the large hose on the thermostat housing and still, water was free and in large volume.
[ATTACH=CONFIG]524230[/ATTACH]
Next, I was able to reach the hose clamps on the intake hose at transom water neck. I was able to turn both clamp screws about 2 full turns. I'm not sure if this is enough to induce an air leak, but could be??? I've noticed no water leaking at this connection, however.
Lastly, I checked the nylon balls and springs in the thermostat housing (thought I'd been in there before, but I was mistaken). They were very loose, and springs were worn out. Based on water flow diagram, I'm not sure how this would control block water pressure - but they need to be replaced, so that will happen hopefully this week).
[ATTACH=CONFIG]524231[/ATTACH] [ATTACH=CONFIG]524232[/ATTACH]
Thoughts?
I believe the intake hose is past due for a change - it's highly worn at the sea pump end. If the inside is as bad as outside, then it could be sucking it closed under high rpm. As long as I get the hose off the transom water neck! Its pretty far down to get a good grip on it (blowers/fuel injection in the way). Won't hurt anything to change it though.
[ATTACH=CONFIG]524228[/ATTACH]
I hooked an electric water pump motor to the inlet of the first cooler (fuel cooler). Water ran freely and in large volume from the exit of the fuel cooler. So I believe it is wide open and not clogged. I also checked for same flow at the exit of the power steering cooler. It too ran freely with large volume. So that confirms that my oil cooler and power steering coolers are still free (I removed both of them last week to confirm by eye that they are clear). Then I checked at the large hose on the thermostat housing and still, water was free and in large volume.
[ATTACH=CONFIG]524230[/ATTACH]
Next, I was able to reach the hose clamps on the intake hose at transom water neck. I was able to turn both clamp screws about 2 full turns. I'm not sure if this is enough to induce an air leak, but could be??? I've noticed no water leaking at this connection, however.
Lastly, I checked the nylon balls and springs in the thermostat housing (thought I'd been in there before, but I was mistaken). They were very loose, and springs were worn out. Based on water flow diagram, I'm not sure how this would control block water pressure - but they need to be replaced, so that will happen hopefully this week).
[ATTACH=CONFIG]524231[/ATTACH] [ATTACH=CONFIG]524232[/ATTACH]
Thoughts?
I have no idea. My 575s run 8psi on one side, 10 psi on the other cruising. At wide open I have never looked at them. Both engines run right at 130 degrees even after long hard runs (aftermarket thermostats)
A collapsed intake hose I guess is possible, however it is a think wire reinforced hose that can hold the weight of a man new, but I guess possible.
Pop the drive off and inspect water intake and channel there? Oring water jacket seal on drive? Any damage or additions on the bottom that side that could be effecting water flow to the drive? Impeller center spinning in outer rubber (this happened to me once, drove me nuts)?
I think you can leave exhaust out of the equation, usually lack of flow there raises water pressure.
Sorry for the rambling, I am puzzled
06-04-2014, 10:50 AM
#30
Registered
Well, I learned a couple of things last night while continuing to troubleshoot.
I believe the intake hose is past due for a change - it's highly worn at the sea pump end. If the inside is as bad as outside, then it could be sucking it closed under high rpm. As long as I get the hose off the transom water neck! Its pretty far down to get a good grip on it (blowers/fuel injection in the way). Won't hurt anything to change it though.
[ATTACH=CONFIG]524228[/ATTACH]
I hooked an electric water pump motor to the inlet of the first cooler (fuel cooler). Water ran freely and in large volume from the exit of the fuel cooler. So I believe it is wide open and not clogged. I also checked for same flow at the exit of the power steering cooler. It too ran freely with large volume. So that confirms that my oil cooler and power steering coolers are still free (I removed both of them last week to confirm by eye that they are clear). Then I checked at the large hose on the thermostat housing and still, water was free and in large volume.
[ATTACH=CONFIG]524230[/ATTACH]
Next, I was able to reach the hose clamps on the intake hose at transom water neck. I was able to turn both clamp screws about 2 full turns. I'm not sure if this is enough to induce an air leak, but could be??? I've noticed no water leaking at this connection, however.
Lastly, I checked the nylon balls and springs in the thermostat housing (thought I'd been in there before, but I was mistaken). They were very loose, and springs were worn out. Based on water flow diagram, I'm not sure how this would control block water pressure - but they need to be replaced, so that will happen hopefully this week).
[ATTACH=CONFIG]524231[/ATTACH] [ATTACH=CONFIG]524232[/ATTACH]
Thoughts?
I believe the intake hose is past due for a change - it's highly worn at the sea pump end. If the inside is as bad as outside, then it could be sucking it closed under high rpm. As long as I get the hose off the transom water neck! Its pretty far down to get a good grip on it (blowers/fuel injection in the way). Won't hurt anything to change it though.
[ATTACH=CONFIG]524228[/ATTACH]
I hooked an electric water pump motor to the inlet of the first cooler (fuel cooler). Water ran freely and in large volume from the exit of the fuel cooler. So I believe it is wide open and not clogged. I also checked for same flow at the exit of the power steering cooler. It too ran freely with large volume. So that confirms that my oil cooler and power steering coolers are still free (I removed both of them last week to confirm by eye that they are clear). Then I checked at the large hose on the thermostat housing and still, water was free and in large volume.
[ATTACH=CONFIG]524230[/ATTACH]
Next, I was able to reach the hose clamps on the intake hose at transom water neck. I was able to turn both clamp screws about 2 full turns. I'm not sure if this is enough to induce an air leak, but could be??? I've noticed no water leaking at this connection, however.
Lastly, I checked the nylon balls and springs in the thermostat housing (thought I'd been in there before, but I was mistaken). They were very loose, and springs were worn out. Based on water flow diagram, I'm not sure how this would control block water pressure - but they need to be replaced, so that will happen hopefully this week).
[ATTACH=CONFIG]524231[/ATTACH] [ATTACH=CONFIG]524232[/ATTACH]
Thoughts?
I'm dead serious about my balls. My old balls hung loose, my new balls are snug to the tube. At idle my pressure went from 0psi to 1. At WOT it went from 18psi to 30+(I backed off) on one engine and 12psi to 20+ on the other. Now I have to decide how to lower it and figure out why one engine is still lower in pressure. To lower it I can raise the through hull pick ups, or, lower the pressure relief tension on the strainer, or, loosen my balls a little.
