Volvo B20 water in oil

[Hofty]

Purchased this boat knowing of this issue. So previous owner did not winterize the motor. Now there is milky oil.

- Where or what do I start with to figure out the severity of the leak and where it is coming from?
- On other forums folks have alluded to potentially the water pump failing and leaking water into the oil that way. This can't possibly be the issue
- Next thought is the head gasket but would prefer not to go that path unless totally necessary

See pictures attached. Any advice would be appreciated.

 

[Hofty]

Pulled the plugs. Sprayed fogging oil into all 4 cylinders and left for 4 hours to penetrate. Slowly turned over the crankshaft and it rotates. Little tight but she rotates.

Noticed one core plug had popped out behind the intake manifold. I'm going to slowly dig away to figure out this issue and get this motor running if at all possible.

 

[Scott Danforth]

Not winterized and a core plug out and now water in oil means the block is busted


Most likely manifold too.

Start looking for new long block

 

[Bondo]

Purchased this boat knowing of this issue. So previous owner did not winterize the motor. Now there is milky oil.

Ayuh,...... Find another B20 that wasn't frozen, 'n busted,.....

 

[kenny nunez]

Other than the engine or the head there are other places that put water in the oil.
The engine oil cooler is one of them. As previously mentioned the water pump is also a possibility..
You need to get all the rubber sealing grommets that seal the pipes along with a gasket set. The block may still be good.

 

[Hofty]

Other than the engine or the head there are other places that put water in the oil.
The engine oil cooler is one of them. As previously mentioned the water pump is also a possibility..
You need to get all the rubber sealing grommets that seal the pipes along with a gasket set. The block may still be good.

So if the current engine works. That's a HUGE bonus. I get a tax refund each year which makes a engine repower an option. I would like to use current motor yet also hoping its toast so i Can invest in a total rebuilt or fuel injected model. Either way this old lady will run nice when done!!!!

 

[Scott Danforth]

so i Can invest in a total rebuilt or fuel injected model.

There isn't a marine fuel injected motor that will replace the B20 easily.

 

[Hofty]

There isn't a marine fuel injected motor that will replace the B20 easily.

What do you mean there is not a marine fuel injected motor that will replace the B20? I was thinking of a Crate Mercruiser motor to repower?

 

[dubs283]

Smallest crate motor you can get from merc with efi is a 4.3 or 4.5 these days.

Actually unsure of the 4.3, they're rare in the oem marine world these days aside from the used market

You could try to source a used 3.0 ec mcm motor, I've seen a couple in babyliners recently. Number one failure ime has been r and r intake/exhaust manifold due to not winterizing

 

[Scott Danforth]

What do you mean there is not a marine fuel injected motor that will replace the B20? I was thinking of a Crate Mercruiser motor to repower?

And bolt to what? The B20 PDS housing will not bolt to a GM motor. And the transom shield is a 4-cylinder only setup

You need VP AQ series PDS housing and transom shield from behind a V8 for your vintage drive, and you have to swap the lower to get the right gear ratio.

You could source a 1986-1990 vintage 280 or 290 setup and swap in.

If you want to change drive to anything else like a newer SX drive or even a Mercruiser setup, that means full transom replacement. The hole for an AQ series is about 2x the keyhole of today

There are the conversion kits that came out to put an SX drive (or Mercruiser) in a transom originally rigged for an AQ. The casting alone was well over $1200 last time I saw one in 2018. Yet alone the whole kit which is NLA

While you could spend lots of money converting the boat to EFI by swapping everything, ask yourself "is it worth it"?