Penta 3.0 GS overheating, U-Shaped hose pressure.

[griffin21]

Hello All,
I am new to this forum. Great info.
I have a 97 Volvo Penta 3.0 GS. Overheating, gauge over 200F when on plane @ 3500RPM.
High pressure in the U-shaped hose between stat housing and circulation pump, NO pressure in the hose from stat housing to manifold. Overheating when on plane @ 3500RPM, Temp creeps up to 190-200F on the gauge. Using an infrared thermometer, the manifold registers 200F + at several points. The riser is always warm to the touch, never too hot. The engine block register approx 150-160F on the IR Thermometer.
Last summer I replaced several parts: new gauge, new temp sender, new stat, new impeller (old one was intact, only 1yr old), removed and inspected the riser (appears clear, no significant rust), removed the outdrive, and inspected water passage (flapper not found).

With garden hose and muffs, it appears to have nice water flow out of the outdrive.
Still overheating at high rpm, cools down to 170F on lower RPMs after coming down from plane..
Is it normal for the manifold to run at 200F ?
How can I test the circulation pump? The Circulationpump and the manifold are the 2 components that I did not remove/check last summer.
Any suggestions on where the issue is? Any help is very much appreciated
Thank you in advance

 

[alldodge]

Check the fitting on top the drive that the intake hose connects to. Many times the fitting gets corroded and restricts water flow

Can also get a piece of clear hose from the HW store and place it inline using barbed fittings. Connect it at the thermostat where the hose comes from the drive/raw water pump

 

[griffin21]

Check the fitting on top the drive that the intake hose connects to. Many times the fitting gets corroded and restricts water flow

Can also get a piece of clear hose from the HW store and place it inline using barbed fittings. Connect it at the thermostat where the hose comes from the drive/raw water pump

Thank you alldodge for your help and for the info.
I will try the clear tube to check for air bubbles.
How do I go about checking the intake hose fitting?
Do I need to pull the outdrive? What is involved in replacing it if corroded?
Thank you, I appreciate your help.

 

[alldodge]

Depends on which drive @kenny nunez

 

[griffin21]

Depends on which drive @kenny nunez

Thank you alldodge. It is a Penta SX-C Part No. 3868391

 

[alldodge]

Being a SX it doesn't have the piece I was thinking about. Yours has a tube (item 62) and its not mounted on the top like the older ones I was thinking about.

It does use a plastic fitting (item 18) which is known for cracking. The clear hose would show it this is the issue with bubbles

https://www.marinepartseurope.com/e...s.aspx?Catalog=7749307&Category=44&View=10670

 

[JayBird2015]

Hey Griffin21. What was your outcome? I am still working on mine.

Volvo Penta 3.0 I/O Overheating. Brand New Engine!

Just purchased my first Volvo Penta IO. It's a BRAND NEW "Michigan Motorz" engine put in last fall. She was run for a short period, less than an hour I was told by the seller. It was winterized by the marina and stored until the end of April. I closed the deal this past Monday. Took her...

forums.iboats.com

 

[griffin21]

Hey Griffin21. What was your outcome? I am still working on mine.

Volvo Penta 3.0 I/O Overheating. Brand New Engine!

Just purchased my first Volvo Penta IO. It's a BRAND NEW "Michigan Motorz" engine put in last fall. She was run for a short period, less than an hour I was told by the seller. It was winterized by the marina and stored until the end of April. I closed the deal this past Monday. Took her...

forums.iboats.com

First off, "Thank You" Alldodge for the quick reply and for the info. Very much appreciated!
I picked up the braided clear tube, barbed coupler, and hose clamps from the hardware store.
Unfortunately, I have not had a chance to install them and test the boat yet.
I will post an update as soon as I have any new info to share. Thank you.

 

[griffin21]

First off, "Thank You" Alldodge for the quick reply and for the info. Very much appreciated!
I picked up the braided clear tube, barbed coupler, and hose clamps from the hardware store.
Unfortunately, I have not had a chance to install them and test the boat yet.
I will post an update as soon as I have any new info to share. Thank you.

Hi All,
Thank you All for your replies and help. My overheating issue has now been resolved. I contacted an experienced mechanic that is familiar with this engine and serviced my boat before I owned it and he pointed me to the correct resolution. He remembered a Volvo Service Bulletin for this engine addressing water cooling system upgrade.

I will share this info, hoping it will help others in the future.
Engine:
1997 Volvo Penta GS 3.0L
Issue:
Overheating within minutes on plane at 3500RPM - 200F on the gauge.
Symptoms:
High pressure in the U-shaped hose between stat housing and circulation pump (feels like a tennis ball at idle speed), NO pressure in the hose from stat housing to manifold (even when the gauge is registering 190-200F and the stat "should" be open), I can press the rubber elbow hose with my 2 fingers and do not feel any water flowing to the manifold and do not feel any pressure.
I think the Stat is just sitting in a cold pocket and never opens.
I think the overflow water flows ok from the stat housing to the elbow/riser.

Using an infrared thermometer, the manifold registers 200F - 205F or higher at several points. The elbow/riser is always just warm to the touch, never too hot (90F). The engine block register approx 150-160F on the IR Thermometer.
No blockage in the water passages, no flapper, no impeller vanes.
Resolution:
There is a service bulletin about upgrading the water system in Penta 3.0 GS

New Service Kit Thermostate Housing. Part# 21163552 (includes Stat housing, hoses, etc..)

Volvo Service Bulletin dated 09-2006 Group 20-0, Number 11, Version 03. Page 4 Talks
Here is the link to the service bulletin.
https://www.yumpu.com/en/document/read/30962697/30-l-upgrades-sx-marinemechaniccom

Or just upgrading the thermostat housing to the new part #3861409 superseeds to 3861550 and not the entire Service Kit.

This resolved the overheating issue and the high pressure in the hoses and the extremely hot manifold. Now the manifold is just hardly warm to the touch.
It seems that overheating issues are not easy to troubleshoot.
I hope this helps. Good luck to all!
Thank you.

 

[alldodge]

Thanks for the info.
Would be nice if the Bulletin was pdf, but will save as jpg for later ref