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Cooling issue 1996 4.3

R

roncon

Member
"I recently purchased a 1996 4 winns with a 4.3 ltr engine.The owners manual says it has a 4.3 GL, however I suspect that the motor was changed as there is a sticker on a valve cover indicating it is a 432A engine.
My issue, the engine runs cool, so cool that the temp indicator does not register,the manifolds are "lukewarm'. At first I suspected the indicator, however I have since ruled this out.
I suspected that it did not have a thermostat but upon checking I found one, old but tested and opening at approx 160 degrees.
I wonder now if the thermostat is the correct one.
As far as I can determine, the 432A calls for a 876305 unit, the 4.3Gl calls for a 3856961.
Are there any physical differences between the two?
The present set up has a "O" ring as well, I also checked the bypass and it is clear of any debris.
Any suggestions gents?
all appreciated
thanks"
 
"The manifold risers being onl

"The manifold risers being only warm is good. With enough raw water circulating through them, they should be warm to the touch only with exception to some idling conditions when just coming off plane.

The engine temp, however, should be higher.

Depending on Raw Water cooled or Closed Cooling system, Salt Water use or River/Lake, you will select your stat temperature range.
If RW Cooled....... then you want a cooler stat for Salt Water use as to reduce salt crystallization (salt begins to crystallize at around 145*)
Keep it warmer if used in River/Lake water.

If all is good, and if all is factory, the correct thermostat should take care of this."
 
"Thanks,I run in river/lake wa

"Thanks,I run in river/lake water and have a raw water cooling system.
Do you have any suggestions as to what could cause the motor to run so cool?
Are there any physical differences between thermostat for 432A and 4.3GL?
thanks again"
 
"Here is the system for the 43

"Here is the system for the 432A
Volvo Penta exploded view / schematic / COOLING SYSTEM | 432A,434A432A,434A

%2C0061.aspx,[url]http://www.marinepartseurope.com/en/volvo-penta-explodedview-773626 0-02B-02B,,,0061.aspx[/url]

Here is the system for the 4.3 GL E of which is a Closed Cooling system.
Volvo Penta exploded view / schematic / Circulation Pump and Thermostat | 4.3GL-EF4.3GL-EF

http://www.marinepartseurope.com/en/volvo-penta-explodedview-7745510-26-8549%20. aspx

If either of these links to not work, go to http://www.marinepartseurope.com/en/volvo-penta-spare-parts.aspx and select from each of the four drop down menus and enter your model number.

I'd need to know if your engine is Raw Water cooled, or is equipped with the Closed Cooling system in order to help you.

You may want to borrow an infrared heat sensor gun and verify your engine temp against the helm instrument.

."
 
"System is raw water cooled, a

"System is raw water cooled, and I have utilized a infrared sensor gun, this is how I determined that the helm instrument is correct.
thanks"
 
"Well, in either event, the th

"Well, in either event, the thermostat's job is to hold back coolant (whether raw water cooled or E/G/h2o closed system) until engine temperature dictates that the thermostat opens up and releases coolant.
This is how the engine temperature is controlled.

IOW's..... with a RW System, the engine's centrifugal Circ Pump provides only that cooling water TO THE ENGINE via an "As Needed" basis.
The balance of the cooling water (from the sea water pump) is sent on to the exhaust system where it cools the mans and is then discharged into the exhaust via the riser ports.
(This sea water supply is relative to engine rpm.)

So, I'd suggest that you either have a thermostat issue, or something wrong in the actual T stat housing, IMO.
There should be no large "thermostat" by-pass in this housing! Only the little air bleed hole in the stat itself.... if so equipped!

By chance do you have an incorrectly installed/plumbed Cabin Heater or WH?

."
 
"No wh or cabin heater.
I am

"No wh or cabin heater.
I am even more confused now. The schematic(s) shown look like I have a 4.3 ltr GL housing, perhaps the previous owner swapped engines and attached GL exterior parts to a 432A block. Make any sense?
I would also like to comment regarding this forum.
To have people contributing their knowledge (derived from experience) is great.
Knowledge is wonderful, to share it goes one step further. Thanks to all that share!!!!"
 
"Ron, something is not right h

"Ron, something is not right here.
Can you post or link us to some photos of this engine and T stat housing?
Or you may email them to me.
Be sure to include a subject re; Marineengine.com forum, etc.

Low resilution is fine.... easier/faster download for me that way.

Rick"
 
"Rick, thank you!
I will do t

"Rick, thank you!
I will do that when I get home (Canada), I spend the winter in Florida and am thinking of the various things that I can address on the boat when I get home.
thanks again
Ron"
 
"That's it? You're goi

"That's it? You're going to leave us hanging until then?
blush.gif
Man..... that's not fair!

Well, with my fading memory, you may need to remind me about this if you were to send an email when you get back. "
 
"Hey Ron
I am not much of a m

"Hey Ron
I am not much of a mechanic but was able to solve a similar issue with my 4.3. In my situation, I had a water pump impeller go bad which the mechanic replaced. After that, my engine ran cool maybe 100 degrees rather than the 160 it should. My fix ended up being simple; there was a small piece of the impeller lodged in the thermostat housing blocking the bypass opening partially. I had to remove the thermostat housing and feel in there with my fingers and eventually had to use a very skinny screw driver to get the obstruction out. I couldn’t believe that it could stay lodged with the amount of pressure in the cooling system. I had initially done a visual inspection seeing nothing because the plugged opening wasn’t directly visible by looking at the housing. If this is your issue, it sure beats replacing parts.

Chris"
 
"Ron, the 432a is a differant

"Ron, the 432a is a differant vintage engine than should be in your 1996 boat. The 432a was last produced in 1993. As you suspect, someone transplanted the thermo housing from the 4.3gl to the 432a. This thermo housing uses a small diameter thermo that sits UP INSIDE the tehrmo housing and is held in place by the O-ring. If you have a regular "auto-motive" style thermo sitting down ON the intake than the water will not be directed properly. We see this alot here in our shop as alot of do it yourselfers dont know the thermo is up inside the housing...even got one in here once that had BOTH thermos installed! Hope this helps."
 
"Gentlemen, thank you very muc

"Gentlemen, thank you very much for your response(s).
Chris, I have checked the bypass opening and I am satisfied that there is nothing lodged in the bypass.
Joe, I think that you may have hit upon the problem,the thermo hsg is exactly as you have described it. To be clear in my mind (difficult at the best of times)should I replace the thermo with a new one for a 432A and insure that the spring end which has the heat sensor or pellet facing down into the block or intake of the engine.
Do I have it right ?
As a matter of interest, any major differences between 432A and 4.3GL ?
thanks again for your interest."
 
"Ron, Joe touches onto an issu

"Ron, Joe touches onto an issue that is important! Follow that lead!

Aslo, in post # 4 I provided two links for you. Did these not lead you to any useful info?

BTW, one of the V-8 stat housings may work also.

."
 
"Ron,glad to hear we may be on

"Ron,glad to hear we may be onto something.The 4.3gl was introduced in 1994 and its cooling system is very simular to an OMC.Makes sense as this was the year that Volvo Penta bought out OMC motors and the Cobra drive rights.In fact the thermo housing is exactly the same.The 432a production was suspended after 1993 and has a completely differant thermo housing.My Volvo Penta EPC does not allow for me to send you copies of the parts pages so you can visualy see the differance.Perhaps Ricardos' links will help.If not,let me know and perhaps I can fax the pix to you?"
 
"Ricardo, yes your links were

"Ricardo, yes your links were very helpful,however after I get home in the spring I will take pictures of the hsg I have as well as the matching block (?) mounting area and forward them along to you for comments. At this point I am pretty sure that I have the 4.3Gl hsg and that the thermostat is installed correctly. What I am not sure of is the "matching" of the hsg to the 432A block and if it is compatible.
You guys are amazing with your suggestions and offers of help. Thank you!!!"
 
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