Logo

AQ225D water in oil

I looked at a boat to buy, checked the oil and looked good. We put muffs on and started it and it sounded great, oil pressure jumped right up and temp got to normal and stayed there. We finally agreed on a price so I bought it.
After running on the muffs at home I happened to check the oil again and it's a milkshake.
I'm going to drain and flush a couple of times. I haven't dug into the manual to much yet, does it have an oil cooler?
What should I look at first?
Thanks for any ideas. Mike
 
......................
I looked at a boat to buy, checked the oil and looked good. We put muffs on and started it and it sounded great, oil pressure jumped right up and temp got to normal and stayed there. We finally agreed on a price so I bought it.
After running on the muffs at home I happened to check the oil again and it's a milkshake.
I'm going to drain and flush a couple of times. I haven't dug into the manual to much yet, does it have an oil cooler?
The AQ225D will not have an engine oil cooler.....
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7743320-21-17192.aspx

If equipped with Power Assist Steering, it will have a cooler for the PA fluid.


What should I look at first?

Before you remove the cylinder heads, perform a cylinder Leak-Down test. Not a Compression Test.... a Leak-Down test!

Thanks for any ideas. Mike
 
Thanks, no power assist steering. I guess a leakdown test will give an idea of ring and valve condition before I look for where the water is coming from .
It is odd that the oil was fine after running it before I bought it. I did run it a lot longer and I have a lot more water pressure here.
If worse case are intake and exhaust manifolds the same for a 305 and a 350?
If I do have to replace I would rather go 350 or 383 stroker.
 
..........
Thanks, no power assist steering. I guess a leakdown test will give an idea of ring and valve condition before I look for where the water is coming from .
The cylinder leak-down test may also reveal cracks that may lead into the cooling jackets.
With the Engine Circulating pump removed, insert your stethoscope into the cooling jacket area as you pressurize each cylinder.
If no results, you may need to block-off and pressurize the cooling jackets.


It is odd that the oil was fine after running it before I bought it. I did run it a lot longer and I have a lot more water pressure here.


If worse case are intake and exhaust manifolds the same for a 305 and a 350?
Yes!

If I do have to replace I would rather go 350 or 383 stroker.
 
The leakdown will tell you several things mostly the overall health of the engine. As you pressurize each cylinder check three areas with your stethescope. In the intake manifold for intake valves, exhaust for exhaust valves and crankcase for rings. If you get hissing in the thermostat hole that would be a cracked head or head gasket. I just use a length of vacuum tube or fuel line as a stethescope. Put one end in your ear and search with the open end. It works great for vacuum leaks the closer you get the louder the hissing. For exhaust you will hear a ticking noise the closer the louder.
 
Sorry it has been so long, I hate typing.
I pulled the raw water impeller and did a couple of oil changes to get rid of any water.
I pulled the intake and there is a cracked water jacket into the valley.
This has been parked since 1997,I guess the crack was rusted over and all the heat cycles opened it up.
Seeing as I have time I think I'll braze it up. If it doesn't work all I'll be out is the cost of intake and valve cover gaskets.
Compression and leak down were good.
 
I wish it was the intake but the crack is in the block.

Mike, that's a real bummer..... sorry to hear that!
When I read; "I pulled the intake and there is a cracked water jacket into the valley", I made the assumption that the crack was in the intake manifold.


In order to properly weld repair a cast iron cylinder block, the block would be stripped, cleaned and heated in an oven.
The oven heating will bring it up to a temperature that will allow for an Arc or TIG weld using NI Rod. TIG would be best!
Otherwise, you will end up with a weld area that is more brittle than the surrounding areas, and it will eventually crack again.

Since the cylinder block would already be stripped of crankshaft, rods, pistons, cam, etc,........ you may as well pick up good used 5.0L automotive cylinder block and re-build it using your re-usable existing components.
Or.... pick up a good 5.7L core and re-build it.




.
 
Last edited:
I brazed a crack on my old farm truck and it lasted many years until I scrapped it. If it would have failed I would have smelled coolant or it would have got hot. This being internal I would only know by milky oil or when it went bang.
I don't want to mess with rebuilding an engine now so I'll buy a long block 350.
 
...................
I don't want to mess with rebuilding an engine now so I'll buy a long block 350.

Use caution..... many rebuilders use the GM full dished pistons.
There is a much better choice, and it won't break the boat bank.
 

Attachments

  • Dished Piston.jpg
    Dished Piston.jpg
    4 KB · Views: 85
I have repaired sbchevs with careful cleaning, grinding and Marine Tech epoxy. EXACTLY what you have....I know where they crack. One 350 is still running strong to date. Repaired it over 20 years ago. The porosity of cast iron yields itself well to Marine Tech or even standard dry time JB Weld. Clean it up, heat a little with propane and wash with Dawn to draw oil out. Grind area to allow the epoxy a good grab. Wash and heat again. Apply epoxy. They always crack right above lifter bores. This is a darn good repair if done properly.
Rick....check out "Winterizing".
 
One more note. Drill a 1/8 or 5/32 hole at each end of crack to help terminate any possible continuance before you epoxy.
 
Back
Top