1998 4.3 GL Head Replacement

[drew_caplan]

Hey everyone!

I have a 1998 Volvo Penta 4.3 GL that didn't survive winter. I have been winterizing boats a long time so not sure if I did a poor job and missed something or it was just bad luck. The motor only had 113 hour on it and when I went to start it I noticed water coming out between the exhaust manifold and the head. I was hoping it was just a gasket gone bad, but when I pulled it off I found the head cracked at the frost plug. (see image). The engine ran great, but alas, here we are. I am looking to order a new head, located in Canada and trying to make sure I order the correct part. Any advice on where to find one and how to make sure it is the correct head for this motor; I am seeing a lot of variation in images when I find them online. Also, any advice on replacing this head would be appreciated; I am mechanically inclined but this is my first head replacement.

Thanks!

 

[Bondo]

Ayuh,..... The odds are slim to none, that just the head froze with water in it,....
Water would also be in the block too,.....

 

[drew_caplan]

Ayuh,..... The odds are slim to none, that just the head froze with water in it,....
Water would also be in the block too,.....

Well the block seems to be intact and is the engine is actually running fine. I did a visual over the entire block and there was antifreeze in the block that came out. So I am thinking that most of the anti-freeze was throughout the engine, just not in the one head, hence the crack. I have checked all frost plugs and nothing else looks out of normal externally. I also ran a compression test and all looks good.

 

[Lou C]

It’s just a Chevy 4.3 V6 (probably Vortec) cyl head nothing special. Remove the valve cover & get the casting number & visit a machine shop…

 

[drew_caplan]

It’s just a Chevy 4.3 V6 (probably Vortec) cyl head nothing special. Remove the valve cover & get the casting number & visit a machine shop…

Yep, it says Vortec on the valve cover. Thank you in advance.

 

[Lou C]

Sometimes the blocks crack on the inside, where you can't see it till the intake manifold is removed. You'll know more when you get the intake off and can see the block area in the cam valley. These engines were used in Chevy Blazers and S-10 pick up trucks so those heads should be easy to find remanufactured. The main thing is to match up the casting #s.
Here's an example:

GM 1997-2001 4.3 LTR /262 ci - V6 cyl Cylinder Head - Casting : 10235772<br />12556140

machineworldny.com

this place is local to me and I got a pair of pre-Vortec cyl heads for my top end overhaul about 7 years ago from them. The main thing is to have the casting #s which you have to remove the valve cover to see.

 

[drew_caplan]

Sometimes the blocks crack on the inside, where you can't see it till the intake manifold is removed. You'll know more when you get the intake off and can see the block area in the cam valley. These engines were used in Chevy Blazers and S-10 pick up trucks so those heads should be easy to find remanufactured. The main thing is to match up the casting #s.
Here's an example:

GM 1997-2001 4.3 LTR /262 ci - V6 cyl Cylinder Head - Casting : 10235772<br />12556140

machineworldny.com

this place is local to me and I got a pair of pre-Vortec cyl heads for my top end overhaul about 7 years ago from them. The main thing is to have the casting #s which you have to remove the valve cover to see.

Thank you in advance!

 

[Scott Danforth]

Verify it is a vortec head (8 intake bolts)

Any 1996 - 2003 GM truck with a 4.3 V6 in your local salvage yard will have the same head.

However you should look at the other head and block as well. The chances of just a single head being freeze damaged is extremely low

 

[drew_caplan]

Verify it is a vortec head (8 intake bolts)

Any 1996 - 2003 GM truck with a 4.3 V6 in your local salvage yard will have the same head.

However you should look at the other head and block as well. The chances of just a single head being freeze damaged is extremely low

Thanks for your help!

 

[Lou C]

This is one of the issues with raw water cooling on an inboard. In salt water you get flakes of rusted cast iron that can clog drains and even in freshwater you get sand and silt that can block drains. Rodding out those drains and making sure that everything drains is very important. I have a relative with a 2020 Merc 4.5 with the single point drain. What I told him I’d do is this, while it’s still fairly new and everything drains well, collect the drain water & measure it. Write this on a tag in the engine compartment. Then each time you winterize it measure what comes out. That’s the only way I can think of to know when it’s starting to clog.
Back on my pet soap box, ALL cast iron GM inboards should be closed cooled, at least a half system. That would avoid this catastrophic damage & let them run at the temp GM intended with pressurized coolant with corrosion inhibitors….

 

[drew_caplan]

This is one of the issues with raw water cooling on an inboard. In salt water you get flakes of rusted cast iron that can clog drains and even in freshwater you get sand and silt that can block drains. Rodding out those drains and making sure that everything drains is very important. I have a relative with a 2020 Merc 4.5 with the single point drain. What I told him I’d do is this, while it’s still fairly new and everything drains well, collect the drain water & measure it. Write this on a tag in the engine compartment. Then each time you winterize it measure what comes out. That’s the only way I can think of to know when it’s starting to clog.
Back on my pet soap box, ALL cast iron GM inboards should be closed cooled, at least a half system. That would avoid this catastrophic damage & let them run at the temp GM intended with pressurized coolant with corrosion inhibitors….

This is a great idea, thank you very much.

 

[drew_caplan]

Alright, so all of you were right, I had cracks in the valley. I am ordering a new long-block for it but I need to identify whether I have a 090 or 090M. Not the best news but honestly, with the price of a rebuilt head up here in Canada it isn't that much more to get an entire long block from Atlantic Marine.

 

[drew_caplan]

Alright, so all of you were right, I had cracks in the valley. I am ordering a new long-block for it but I need to identify whether I have a 090 or 090M. Not the best news but honestly, with the price of a rebuilt head up here in Canada it isn't that much more to get an entire long block from Atlantic Marine.

 

[drew_caplan]

Never mind, found it! For anyone else in the same situation I found it above the starter by sticking my phone camera back there to snap this photo. It is a 090.

 

[Lou C]

The M I think was metric fittings vs imperial

 

[Scott06]

The M I think was metric fittings vs imperial

Yes the 090 M had metric bolts on the starter, side motor mounts, and flyhweel cover. every thing else was SAE... Found this out when I did a 4.3 to 5.0 conversion.

to the OP yes easier if it is a non metric block but a metric will work with about $40 worth of bolts. Michigan motorz also carries remans

Remanufactured Marine Engines - Marine Engines - Products

www.michiganmotorz.com

 

[drew_caplan]

I picked up a long block from Atlantic Marine for 1795 plus shipping to the border. In Canada the best price I could get was $6500 from a reputable builder.

 

[Scott06]

I picked up a long block from Atlantic Marine for 1795 plus shipping to the border. In Canada the best price I could get was $6500 from a reputable builder.

Great price

 

[Donald0039]

Have you figured out what went wrong with winterizing? It's never luck.

My method on raw water cooled Mercruiser

1) drain block on both sides. Poke in hole for rust chunks
2) drain exhaust manifold, drain plugs or pull hoses
3) pull hose from raw water pump to outdrive and pour antifreeze down it
4) pull the top of large diameter hose coming near top of engine and fill with antifreeze
5) pull each hose to riser and pour in some antifreeze
6) if you have a hot water heater you need to pull one end of the hose and blow through it before you put drain plugs back in during #1.

Some people try and suck in antifreeze using muffs. That really only works with outdrives with impeller in outdrive. Merc Alpha One.

Some people have not let the engine fully warm up and the thermostat full open. If you try and feed in antifreeze and thermostat is not fully open you will not get the block filled with antifreeze.

 

[Scott06]

Have you figured out what went wrong with winterizing? It's never luck.

My method on raw water cooled Mercruiser

1) drain block on both sides. Poke in hole for rust chunks
2) drain exhaust manifold, drain plugs or pull hoses
3) pull hose from raw water pump to outdrive and pour antifreeze down it
4) pull the top of large diameter hose coming near top of engine and fill with antifreeze
5) pull each hose to riser and pour in some antifreeze
6) if you have a hot water heater you need to pull one end of the hose and blow through it before you put drain plugs back in during #1.

Some people try and suck in antifreeze using muffs. That really only works with outdrives with impeller in outdrive. Merc Alpha One.

Some people have not let the engine fully warm up and the thermostat full open. If you try and feed in antifreeze and thermostat is not fully open you will not get the block filled with antifreeze.

See post # 1 OP mentions antifreeze suspect that was the issue flushing with AF vs drain then backfill with AF