Proper Draining of Volvo 5.0 Gxi Raw Water Cooling

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DarinSchmidtMN

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Joined
Sep 6, 2008
RO Number
30712
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48
Hello Everyone,

I am new to the forum but it seems like there is some great information to be found on here. I am hoping someone can help a newbie out.

My wife and I purchased our second boat last fall, a 2003 Larson 31. It has Volvo Penta 5.0 Gxi 270 horsepower engines (with DuoProp out drives, if that matters.) The engines are raw water cooled. My previous boat had a Mercruiser engine, and I always did my own winterization on that engine myself. The drain plugs were easy to find on the Mercruiser engine, but I am having a tough time finding them on these Volvo engines.

On the left side of each engine there is a drain hose with a garden-hose fitting on the end, that appears to be connected to the block and manifold. To me that appears to be for flushing out the engines, but is that how they are drained, too? If I loosen the cap on the hose and lower it down, water flows out. I cannot find any drain plugs anywhere on these engines. I just want to make sure I do this correctly.

Anyone have experience with these engines? Thanks in advance for your help!
 
The drains are located on the lower part of the block. There might be a sending unit (knock sensor)on the starboard side that is round with a single wire that goes to it. The drains are about 1/2 inch in diameter and about 1.5 inches long.

It would be best to remove each one. Then use a piece of wire to make sure the block drains. Usually the block is stopped up from rust, sand, and other debris at this location especially if used in salt or brackish water.

Since you have the VP DP, you need to pull the drive, grease the u-joints, and then reinstall. OR there is a drain on the starboard side of the drive that MUST be rodded out and then hope all the water drains.

Ken
 
Didn't we see one of these Volvo drives cracked this spring from water that froze during the winter? Don't they self drain like Mercs?
 
Yea, there was one that had water trapped that cracked. I helped the RO figure what had happened. Volvo took the position that it was his fault for not pulling the drive for the winter. The drain on side "should" work, however it is VERY possible for it to become stopped up and not function. While I was rebuilding and repainting my drive, I enlarged the drain by about 100%. Freezing is not an issue here, but while I had it apart, I planned for the future.
The pictures he sent me showed how much damage was caused, and let me say it was BAD. It took a long time to get the drive off due to the distorted housing and the fact the gimbal bearing was stuck to the input shaft.
When they did get the drive off, it brought he gimbal bearing out with it.

Ken
 
I read through my Volvo manual (the one that comes with the owners manuals for the boat) and it has a diagram showing the location of the drain points. I guess the block drains from that hose, the only two plugs on the entire engine (according to the picture) are the manifold plugs, one on each side, on the BACK! How do they expect someone to get back there? Maybe in a single engine application that is okay, but not with twin engines. No wonder you never see any overly large marine mechanics!

The manual says to hook up a fresh water hose and flush the engine out without running the engine. I guess the reason for that would be to force fresh water through it, breaking loose any sand or other deposits that could clog the drain holes? Usually I would run a screwdriver or pirce of wire through to break loose any clogs, but with the hose attached to those drain holes I guess that's not a possibility. I am trying to figure out if this was a bad design or not. From what I have been told, anything that is not Mercruiser is superior, but right now I am really starting to miss having those little blue drain plugs!!

So I guess my plan is to do as the book says and flush fresh water through the engines without running them, then when the boat is pulled I'll drain the engines by dropping the hose into the bilge, then somehow get back to the backsides of the manifolds and remove those two drain plugs, then pull the hoses for the thermostat housing and heat exchanger (for the water heater) and then maybe backfill it with the pink stuff, and I should be good to go.

As far as the outdrives are concerned, I think I will leave that up to a mechanic.
 
I just pulled up the manual on that engine. Volvo updated to the flush system you described. You could remove the flush system and install drains if you wanted to. Also, you can remove the hose from each side of the block so that you could run a wire/coat hanger into the block to ensure water is able to get into each bank. I personally would not trust the Y method that is in place.
There are 2 fittings on each manifold, one is in the front the other is in the rear. Depending on the setup, access to the rear ones might be tough. You could always pull the hoses at the front of the manifolds, then either: 1. lower the tongue of the trailer to ensure all the water runs out, or 2. lower the lift (if kept on a lift) to do the same.

Ken
 
Thanks Ken. I had never really looked at that hose along the side of the engine before, I just thought it was for flushing but it turns out it's for draining, too. A friend of mine had a little open bow with a 3.0 Liter Mercruiser and the "quick drain" system. I guess the only difference between this setup and the one I am seeing on my Volvos is the size of the hose. But, if I recall correctly, the little blue hoses drained both the block and the manifold at the same time. I still don't know if I would trust that!

Maybe I will call a local service place and ask them how they do it with those Volvo engines. They'll probably just tell me to let them winterize it, and charge me big bucks to do it. No thanks!

Thanks for the help Ken. I definitely would sleep easier this winter if I know that I got all of that water out. Boring out the drain holes seems to be the only way to be sure it is done correctly, short of hiring the boat yard to do it.
 
quote:
Originally posted by DarinSchmidtMN

....then pull the hoses for the thermostat housing and heat exchanger (for the water heater) and then maybe backfill it with the pink stuff, and I should be good to go.

Click to expand...


Darin - seems you have it down pretty good. Just a small note, you mention using "The Pink Stuff" in your block. Assume you know the difference between that and automotive anti-corrosive antifreeze. Pink stuff is for water systems, not the engine. Many of us use the Prestone Low Tox or Siera brand antifreeze. It contains proplyene glycol which is better for the environment. There are a few threads on this topic.

By the way, I was just at Wally World and started to load up on Prestone pink stuff. They had it on a prominately displayed shelf for $4.98. Behind hidden away on another shelf was the Dow brand pink stuff for $3.93. We buy lots of it for closing the pool and winterizing the boat, so a few bucks saved is good.

Good Luck.
 
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