Overheating continues

[FreeBeeTony]

While out fishing today, I started to hear a noise coming from the engine (165 Mercruiser IL6). I opened the engine cover to listen better and noticed that the hose coming from my H/E (FWC) going to the circulating pump was collapsing! When I backed off the throttle the hose regained its shape. Could this be a clue to my overheating problem? It only gets hot when running around 3000RPM. And I am wondering if the noise I was hearing is the circulating pump.<br /><br />Another question: the return of the raw water going to the elbow is going to a "barb" installed into the elbow. The hose is 3/4" ID. Seems like it would be nice to use a bigger ID hose for less restriction. Are there any bigger "barbs" available that would accept a larger hose and still fit into the elbow?

 

[metwrench]

Re: Overheating continues

I would say maybe the Raw water Pump not feeding enough water ? Intake screens Clean ?? Pump Housing, Gasket and Pump been done ?

 

[FreeBeeTony]

Re: Overheating continues

Pump and housing new, intake clean.

 

[rattana]

Re: Overheating continues

Tony is the hose that is collapsing part of the closed system? Check the pressure in the hose going to the exhaust manifold. If it is soft then it could be the thermostat or housing has a restriction. If the hose after the exhaust manifold is soft the manifold or end cap and gaskets could be the restriction. If all the hoses are pressurized, then you may have to check your HE for restriction. Do you have a schematic of the cooling system?

 

[Boomyal]

Re: Overheating continues

If it was the large hose, from the H/E to the water pump intake, you either have a plugged heat exchanger or a bad supply hose. The engine circulation system is independant of the I/O impeller. The coolant simply circulates from the motor, thru the H/E, into the waterpump and back to the engine.<br /><br />If your exhaust manifold is part of the FWC, then what I've said may not apply. I have no experience with FWC/Exhaust Manifold plumbing.

 

[achris]

Re: Overheating continues

Tony,<br /><br />Is this a Mercruiser genuine FWC system? If so, do you have the 'water reversing kit' on the exhaust manifold? <br /><br />The collapsed hose to the water cir pump is a concern. It indicates that the pump is pulling more water than the H/E can supply. If everything is right, that can't happen. When was the last time you had the H/E professionally cleaned out? Have you checked for the system for leaks, ie with a radiator pressure tester?<br /><br />If I'm coming in part way through a problem, just post the previous thread http address and I'll have a read. <br /><br />Chris.............

 

[FreeBeeTony]

Re: Overheating continues

Just installed the FWC system this spring. It is not a standard Mercruiser system, it's custom. Manifold IS part of the system, after thermo housing and before the H/E.

 

[Bondo]

Re: Overheating continues

Hi Tony,<br />Boomyal is headed to the Right Direction.......<br />I Can't believe your H/E is plugged.......<br />Is there a Coil Spring In-side of the Hose that's Collapsing ???? Maybe there Should Be........<br />This would allow More Water Flow......<br />The waterpump is Pulling more than system can provide......<br /><br />Question #2,<br />Yes, you can get hose barbs with a 1" barb,+ the same size pipe threads as you have Now,<br />But,<br />That's Not your Problem...... And, the Hole in the riser is Still going to be the Same Size........

 

[FreeBeeTony]

Re: Overheating continues

Hey bondo........I can always count on you.<br /><br />I am going to put a spring in that hose.<br /><br />On the riser....I know the hole in the riser will be the same, but if I can increase the hose to 1" ID I am going to. The hole in the riser is 1". I had to reduce the return on the H/E to 3/4", now I can go up to 1", this should increase the raw water flow an add some cooling..

 

[Peter J Fraser]

Re: Overheating continues

Hi Tony,<br />What size is that hose?<br />What about replacing that run of hose with S/steel or copper tubing with short hoses at each end to join to the hose tails?<br />If it has any bends in the run at all the hose will start to collapse from that point from suction.<br />An exhaust shop shuld be able to bend to the shape required or a plumber if the tubing is small.<br />Another suggestion would be to use Hydraulic Hose SUCTION hose as this is made with more reinforcing in the construction to stop it collapsing.<br />Most auto hose is only 1 or 2 plies where as HYD suction hose can be 6 - 8 plies (fabric not steel).<br /><br />Don't give up yet.<br /><br />Regards<br /><br />Peter