running cool

K

KM2

Chief Petty Officer
Joined
Oct 15, 2003
Messages
556
Help I'm losing sleep. I have read every post about cooling in iboats in the last 3 years and I'm not finding anwers. <br /><br />The boat is running cool, never warming up past the 125 degree mark. What I have done- tested the thermostat (160)and it is working but I replaced it anyway. Put in a new impeller a week ago, after an overheat. I believe the temp gauge is working reasonalbly accurate because it was up to 190-200 or so when the overheat alarm went off. After a run I can put my hand on everything -thermostat housing, block etc and it feels only warm. <br /> <br />I have the thermostat installed correctly, I doubled checked that. <br /><br />Any suggestions? <br /><br />4.3 VP 2001 with sx drive<br /><br />P.S. Can someone also explain how the cooling system flows... from impeller to where it exits the drive.
 
Boomyal

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: running cool

You need to get a laser thermometer to verify your guage. Costco has them for about $65.00. You'll wonder why you didn't get one a long time ago.
 
V

vipzach

Lieutenant
Joined
Feb 15, 2005
Messages
1,283
Re: running cool

I agree with boom, get a laser thermo. Possible problems could be the gauge or temp sending unit. Is your boat fresh water cooled od raw water cooled (makes a difference when explaining how water flows)
 
K

KM2

Chief Petty Officer
Joined
Oct 15, 2003
Messages
556
Re: running cool

raw water cooled <br /><br />Thanks guys, I'll hit costco soon. Sounds like a neat toy to have. But, I'm convinced the boat is too cold if it was near 160 degrees I could'nt touch it comfortably.
 
Scaaty

Scaaty

Vice Admiral
Joined
May 31, 2004
Messages
5,180
Re: running cool

Originally posted by KM2:<br /> . Sounds like a neat toy to have.
Click to expand...
Might a well start getting the word out that this is THE ITEM we all want for Christmas!
 
K

KM2

Chief Petty Officer
Joined
Oct 15, 2003
Messages
556
Re: running cool

I not getting back to the boat for 1 1/2 weeks. I'll check the temp gauge then. <br /><br />Can someone explain the cooling system/ water flow? I understand what I can see, the impeller, to thermostat housing ... but where does it go after that
 
R

rbezdon

Senior Chief Petty Officer
Joined
Jun 20, 2004
Messages
689
Re: running cool

Once the stat is open, some of the water goes to the block, some bypasses the tstat and goes to the exhaust manifolds. Eventually the water that passes the stat into the block circulates around it and exits the block into the exhaust manifolds as well. Then the water travels in jackets around the manifold and riser and dumps into the exhaust below the riser and exits the boat through the y pipe (V type engines, in straight type engines pipe is not a y shape) through the transome plate and out the exhaust bellows. Some may actually make it through the drive and out the prop center (except through hull exhaust).
 
K

KM2

Chief Petty Officer
Joined
Oct 15, 2003
Messages
556
Re: running cool

Where can a get a shop manual for my motor and drive? The volvo one not the seloc or cylmers.<br />Any idea what that is going to cost.<br /><br />01 volvo 4.3gl sx drive
 
R

randyo

Petty Officer 2nd Class
Joined
Apr 8, 2005
Messages
108
Re: running cool

KM2, Im in the exact same position as you. My 4.3 volvo engine rarely gets past 125degrees. I have a heat gun and it agrees with that reading. No idea why here either...I'll be watching this thread for suggestions for myself also. BTW, I couldnt find the volvo manual and settled for an aftermarket one (Seloc).<br /><br />Good luck!
 
Haut Medoc

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: running cool

Try a different stat. They are availible in hotter ranges.....But first, are you sure the hoses are routed correctly? That I can't help you with, unfortunately.....Don S. would most likely be the guy for a picture, though....I would look at that first....And Don knows Volvo inside and out....He will have your answer...JK
 
K

KM2

Chief Petty Officer
Joined
Oct 15, 2003
Messages
556
Re: running cool

I think I have the hoses right. I have looked at a diagram. I did have the impeller hoses backwards but that was only for a few seconds after an impeller replacement. <br /><br />At this point I'm not ruling anything out.<br /><br />FYI: Stemtostern.com has very good diagrams with part numbers.
 
K

KM2

Chief Petty Officer
Joined
Oct 15, 2003
Messages
556
Re: running cool

Checked the temp gauge and it's working perfectly. Took off thermostat housing and cleaned it up a little. Pulled a large piece of my old impeller that was stuck in the housing just passed the impeller hose. Cleaned some rust and crud around the were the thermostat sits and made sure the o ring was in place so the whole thing was sealing up well. On the last trip out it worked as I think it should. Warmed up to 160 degrees and stayed there at idle, cooled down to 150 + when running hard. The water temp here is in the mid 60's. <br /> <br />I'm not sure what the problem was, gauge, thermostat sticking/plugged, O-ring not sealing up... Anyway it's working and I'm happy and can quit obsessing over it and enjo the last few weeks of the season. :p <br /><br />Thanks everyone for your help.
 
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