Oil in heat exhanger, but not anti freeze in oil - how did it get there

[Njrulli]

I have a 1986 bayliner capri with a closed cooling volvo penta aq125b with a 270.

I have redone nearly everything and thought it was running great. My oil pressure dropped a little, and for no apparent reason I took the cap off the heat exchanger and oil mixed with anti freeze gushed out.

I have no loss of power, it is not overheating. I know I am losing oil and it is going into the heat exchanger.

How is the oil mixing into the heat exchanger, if it was a head gasket wouldnt I lose power and have antifreeze in the oil?

I am not sure where to start, any help would be greatly appreciated. For nearly every other fix over the past year I have been able to find the info already posted but this time I can not seem to find anything listed.

Thank you,

Nick

 

[Njrulli]

Re: Oil in heat exhanger, but not anti freeze in oil - how did it get there

Am I the only one to run across this? If you have please tell what the fix was

 

[GA_Boater]

Re: Oil in heat exhanger, but not anti freeze in oil - how did it get there

I'm not familiar with Volvo, but some closed cooling motors also have a separate oil cooler in the mix. Yours?

 

[Grub54891]

Re: Oil in heat exhanger, but not anti freeze in oil - how did it get there

It could be the power steering oil cooler how is the oil in that? Mabe I'm wrong,as the ps cooler might be cooled on the freshwater side of the systym. The heat exchanger might run oil through it,under a small bit of pressure,thus only letting oil out into it,not totally familar with the volvo systym. However it works out for ya,at least ya caught it before the entire thing blew up.
Grub

 

[kamby]

Re: Oil in heat exhanger, but not anti freeze in oil - how did it get there

the 125b i dont think has n oil cooler or power steering i have a 125a and it doesnt have either. My speculation would be a crack in one of the cooling passages letting oil into the water, somewhere in the water pump area maybe or in the block. It could be minor to were it hasnt showed up in the oil yet. only way would be to have the oil sampled and see the glycol levels. Try perhaps draining the antifreeze and refilling, see how bad it really is.. Jd

 

[kamby]

Re: Oil in heat exhanger, but not anti freeze in oil - how did it get there

Also is it going into the exchanger part or the expansion tank. Expansion tank has a radiator cap, exchanger has round twist on cap where the sea strainer is.