Internal Coolant Flush and Winterizing VP 4.3 GXI-BF

[domer7]

Hello,

I have a new to me I/O with a Volvo Penta 4.3L fuel-injected engine with an internal coolant system along with the raw water coolant system. How do I flush the internal system and add new coolant to achieve adequate freeze protection for my area - Wyoming? It currently shows +20 degrees with a coolant bulb tester.

Also, is there a good guide to winterizing the whole engine as I can only find bits a pieces on line. I've drained the raw water pump, removed the hoses at the bottom of the heat exchanger and pulled the plugs on the exhaust manifolds. The boat is garaged, but currently, tho well insulated, the garage does drop down into the 20's. Last winter I put two trouble lights under the engine with halogen bulbs and that kept the block 36-40 degrees.

Thanks,

Steve

 

[alldodge]

I've drained the raw water pump, removed the hoses at the bottom of the heat exchanger and pulled the plugs on the exhaust manifolds.

Remove the block drains, there is one on each side. Re-install plugs and fill with 50/50 or higher concentration.

Don't know of a detailed write up other then the owners manual maybe

 

[BRICH1260]

You need to drain that +20 mixture out of the block as it is too weak a concentration for winter. Like stated above use a 50/50 mixture. You need to drain the heat exchanger, hoses and the manifolds of all raw water. You can leave dry but I prefer filling with good quality pink antifreeze to prevent corrosion. If you do this you will not need to rely on external heat sources.

 

[Scott Danforth]

also good idea to pull the HX end caps and clean out the debris in the tubes

 

[Lou C]

With this job it’s not the draining that’s tricky it’s the refilling & bleeding all the air out. I’d pick up a Lisle radiator funnel kit that makes it much easier to bleed the cooling system. You’ll prob have to run the engine at fast idle 20 min to a half hr to make sure the thermostat opens. In fact I’d probably pick up a few spare thermostat gaskets remove the stat housing and fill the engine with AF, via the opening in the intake manifold, then reinstall the stat housing with a new gasket and refill your H/E. Then use the Lisle radiator funnel to bleed the system; when you get no more bubbles you’re done. Then drain the raw water side of your H/E and manifolds if they are not closed cooled (Volvo exhaust is raw water cooled). You can add no tox AF to both of them if you want to reduce corrosion.
It’s important to get the air out of your closed system or else you can get an air lock and have overheating.

 

[domer7]

Remove the block drains, there is one on each side. Re-install plugs and fill with 50/50 or higher concentration.

Don't know of a detailed write up other then the owners manual maybe

Thanks alldodge but I'm pretty sure this block doesn't have drains due to internal coolant system.

 

[Lou C]

ALL GM marine engines have block drains, they are simply adapted auto engines. You just have to look for them....on the starboard side, between the starter and engine mount, same place on the port side. Even with a closed cooling system when it comes time to change the antifreeze, there would be no way to get all the old stuff out, if there were no block drains.

 

[alldodge]

ALL GM marine engines have block drains,

What Lou said
look for 7/16 hex head pipe plug down low close to the middle of the block

 

[domer7]

Okay - I'll do more investigating! I appreciate the responses.

 

[muc]

Okay - I'll do more investigating! I appreciate the responses.

Might help if you told us what 4.3 you have. If it's the latest generation ---- most everything posted so far is wrong. The new ones do have block drains, but they are in a new place and look very different. Also the new engines need a special coolant.

Use a 13/16 inch wrench, remove the drain plug from
the Front End Accessory Drive (FEAD).

Use an 8 mm ball end hex socket wrench to remove the
starboard engine block drain plug.

Remove the protective rubber cap from the engine
drain plug fitting.
Use an 11 mm wrench and remove the drain plug from
the port engine drain fitting.

 

[Lou C]

Yep it’s hard to give advice when we don’t know exactly what you have. However if it’s the older cast iron version there are 2 plugs on either side of the block, low down not easy to see depends on boat installation. If you do wind up draining the AF remember what I said about bleeding out the air after refilling; trapped air will cause overheating.

 

[ripjmk]

Didn't the OP tell you enough in the title of the post?

VP 4.3 GXI-BF​

Shouldn't that be a red engine around 2001?

 

[Lou C]

Sorry some of us are not fluent in V/Ps arcane and nonsensical model letters/numbers. But now that you posted it....

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Just as I said above, a drain plug on each side of the block like every other Chevy small block V8 or V6....

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Since 1998, iboats is the most trusted water lifestyle online store for boat parts and accessories, boats for sale, and forums. Enjoy great priced products with fast shipping.

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other details that might be helpful....flush system....closed cooling system...etc....

I find it astounding what the mark up is on V/P parts....that can be purchased from other vendors.....they sell a GM Saginaw power steering pump for over 600 bucks....and you can buy remanufactured ones on ebay and other sources for $150 or so, in fact I got a Mopar reman Saginaw pump for our older Jeep for around $125 or so. Another example is a 4bbl Holley carb, that they have the nerve to list for a grand, that you can buy brand new exactly the same thing, from Holley direct for as little as $550 on sale. They charge a grand for the "unrebuildable" Power Steering actuator that is prone to leaks....but there is a place in Fla that will rebuild yours for $450. I found that the older model in my boat, also "unrebuildable" is the same unit used on older Corvettes and Mustangs, and it can be rebuilt with a $50 rebuild kit and maybe 3 hrs on a Saturday. Yes thats the truth, OMC and Merc used this old style actuator with the seperate control valve and hydraulic cylinder (also a Saginaw design) up to 1990 but the parts are still available because people are still restoring old Corvettes and Mustangs!
I feel sorry for people who own these boats and have the marinas or shop do everything. What a racket!
otherwise known as.....
Highway robbery.
If you're going to pay these parts prices you might as well move away from I/Os with their designed in headaches and switch to 4 stroke outboards, at least then you get some real advantages, in safety, maintenance and performance.

 

[muc]

Didn't the OP tell you enough in the title of the post?

VP 4.3 GXI-BF​

Shouldn't that be a red engine around 2001?

Ha Ha, I missed that completely!
Most everything I posted is wrong for OPs engine.
I should have payed closer attention.
Most everything posted by people other than me is correct.

 

[alldodge]

Ha Ha, I missed that completely!
Most everything I posted is wrong for OPs engine.
I should have payed closer attention.
Most everything posted by people other than me is correct.

Always glad to see you comment, your the expert with vp. We all make mistakes and with your current record your hardly ever wrong. All good from my view

 

[Lou C]

Yep muc can teach us things we would never be able to learn thanks for all the help!

 

[muc]

@alldodge and @Lou C thanks for the kind words.
I’m pretty embarrassed right now.
i have 4 pet peeves about this forum.
1. people who start a post without telling us exactly what product they have.
2. people who assume all 4.3s or all Volvo’s — etc etc — are the same.
3. people who reply without completely reading everything the OP posted.
4. people who don’t post a resolution to their problem.
Looks like I’m guilty of breaking 3 of them!

 

[bruceb58]

Sounds like he has a closed cooling system with a heat exchanger. If so, why does he need to drain his block?

 

[Lou C]

I think he said the AF wasn’t strong enough to protect against freezing.
My pet peeve is that people don’t believe in buying shop manuals and self teaching. It’s ok to ask questions but really you need to have SOME base of knowledge!

 

[muc]

Sounds like he has a closed cooling system with a heat exchanger. If so, why does he need to drain his block?

Ha Ha, I see what you did there. Got me on #3
I deserved it.