Engine temp. rising higher than half when planed out...

[Saline Marina]

I believe the thought is related to this: If you pulled the sterndrive and driveshaft off the boat, there's two housings that mate up together as the nuts are tightened, and a "formed o-ring" type seal that is a flange-gasket between the two housings. In function, its between the "gills" where the water is sucked into the lower unit and the flex hose which runs up thru the transom plate.

There also can be o-rings which seal the same flex hose to the transom side of that same cavity.

If any of these seals are compromised, it ends up as the same effect as sucking water thru a cracked straw. Despite best efforts, a lot of air is getting pulled in. I wanted to be sure when i pulled my drive that I didn't create this situation and used a light coat of grey RTV on cleaned and dried surfaces to further enhance the "formed o-ring". It will require a utility knife to carefully slice thru the RTV when i next pull the stern drive but in my mind that's a small price to pay.

 

[Scott Danforth]

its a volvo drive.

pull the drive and carefully inspect the fitting the hose attaches to on the drive. they are problematic. the old castings last about 2 years, the plastic fittings about 3

 

[kenny nunez]

There is a “O” ring that seals the lower gear housing to the stainless swivel tube that goes through the suspension yoke. That is another place that can draw in air when the boat is on plane.

 

[Lou C]

1998 four winns sundowner

OK by the year of the boat it has the SX style drive not the AQ style drive, also those still had flappers I believe they were discontinued around '99 or so....

On this style drive one there are a few trouble areas that come up running on plane...
the grommets in the lower unit for the water transfer tube sometimes rot out and allow air in...
the plastic hose nipple that is in the pivot housing can crack if water does not drain for winterization, that can allow air to be pulled in when the boat is on plane

If it still has flappers, if there were ever an overheat, they can melt and drop down and block the exhaust. Only way to know is remove the elbows and look.

There is a document floating around the net "Volvo Penta Overheat Diagnosis" it is a PDF and gives good troubleshooting hints for this style Volvo.

http://www.volvopentastore.com/Exha...on_id.448951254--store_id.366--view_id.789099

don't know your model # but this shows the flappers...

http://www.volvopentastore.com/Lowe...on_id.448951254--store_id.366--view_id.782033

water tube sealing grommets....

couldn't find the transom mount in Volvo's incredibly difficult to navigate US catalog so found the OMC/Volvo joint venture model which is the same for both OMC and Volvo....

https://www.crowleymarine.com/johnson-evinrude/parts/57052.cfm

water nipple is part 18 in the diagram, says its unavailable but they are still out there if you search on the OEM part #

I was able to buy a few spares for mine a couple of years ago.....

 

[wmubronco]

Great info, thank you for that. Will be able to get back down to boat over the weekend and will start the diagnosis. I'll replace the water seal inside water pump behind impeller. If that does not do the trick, I'll check thermostat. If not there, I'll go down the road of all this great info and let you guys know what I find.

Appreciate it, and have a great week!

 

[Lou C]

see if you can goggle up that document...its really good....

 

[wmubronco]

Replaced entire water pump with brand new one. Old seal inside around shaft had adhered to the metal housing and when I took out old pump, you could tell the bearing was starting to go since some small chunks of metal fell out and had some difficulty spinning freely . Just took it for a cruise and temp creeped up to around 3/4 of the gauge. I used an IR gun near the thermostat at it was just over 160.

maybe thermostat is now the culprit?

 

[wmubronco]

Planed out again and temp on IR gun was around 186.... not good.

 

[Scott Danforth]

And what did the input hose fitting look like?

 

[wmubronco]

And what did the input hose fitting look like?

Will be out of pocket until Monday morning to get back to it. I'm suspecting this is the problem area, and will have to pull boat out of water for this.

 

[harojs]

Manifolds or Risers clogged up? - that would reduce flow needed at planing, but would look ok at idle.

Also, if it is a dropped flapper in the Y-pipe, you can fish it out with a coathanger if you remove top rubber elbow. You have to have a good feel and patience with "coathanger fishing" - it is possible - ask me how I know ...

I also used a $35 endoscope from Amazon that worked with my cell phone to verify the flapper was indeed stuck down in the Y-pipe. Great little tool.

 

[GA_Boater]

Dead thread as the OP has not been around since his post in August.

Closed.