bf150 milky oil from where?

I have a pair of 2003 BF150 outboards, great engines, BUT. The last trip out 1 engine set off the alarm.
Upon investigation, the engine oil was completely full with oil/water.

All the spark plugs are clean and burning fine. No sign of water. The alternator has rusty water marks and pretty bad corrosion, but no leaks when running?


Is there a common place or gasket that fails that can allow the water in the engine oil that is not the head gasket?


I have a copy of the workshop manual and am a mechanic by trade. I just don't want to disturb the whole engine if it is just a cover or gasket corroded.


ANY IDEAS? Please


I bought the boat earlier this year and it has been running fine up untill last trip. So don't know it's service history.

BTW I am in Australia and the nearest service guy is a long drive away.

Thanks,

Tony

I have searched back through most of the old posts and find no one else ever having mentioned this problem.

Maybe it's a rare thing and the head gasket may indeed just be blown?

I doubt it and think the water is getting in through a corroded part internally.

Has nobody come accross this before?

Tony

Good question. I can only think of one other place...there may be more. Thank goodness, I have never had this problem.

But, it should be fairly easy to see it there is a problem.

This is a long shot. Pull the thermostats and inspect the thermostat housing for corrosion. If there is corrosion, the thermstat housing could be leaking directly into the chain case and directly into the oil. There is also a gasket under the chain case directly under the thermostat housing that is supposed to keep the oil and water from each other. See part #16. http://www.boats.net/parts/search/Honda/Outboard%20Engine/2004/BF150A4%20LA%20VIN%23%20BANJ-1000001%20TO%20BANJ-1099999/CHAIN%20CASE/parts.html If that fails....well...you know...

Mike

Thanks Mike,

I will give it a shot and let you know.

Funny I had the thermostats replaced soon after I bought the boat as 1 engine was running rich.
Has only done about 15 hrs since. Maybe the gasket was not replaced or not sitting right?

If I pump air or water up the flushing port, it might be easier to find if it's not the thermostat o rings.
Is there a problem with testing the system like that?

Tony

The gasket I was referring to was not the thermostat gasket...it is the gasket between the chain cover and the engine block.

I would just inspect the thermostat housings for corrosion. If the housing is corroded, then that could be where the issue is.

I am not sure what pumping air into the flushing port will do. If you do, should should limit it to very low pressure. Let us know if it gives you the info you are looking for.

Mike

Finally just pulled the engine apart. I have been away and busy.
The story is, it looks like the Block is cracked from above the starter to the top!!!

It seem to be just a really fine line of salt but I think it is a crack as the alternator and starter and surrounding area is now rusty from the water.

it must be leaking while under full power and the water pressure must be enough to get it to leak on the outside too.

I have the egine on the stand and will strip it as soon as i get some time.


Is it viable to buy a new block and do the rebuild if it turns out to be cracked?


Will the CAR version of the engine be a cheaper option as i can just fit the marinsed bits to it and not have build a complete engine from scratch?

Does anyone know what the model of car engine is the same and IS it the same? And has any one done the swap before?

Thanks,

Tony