OMC Stern Drive 400 - Water in oil - Waterpump housing

[Ottern]

Hi! Been reading up un these forums the last couple of days, and as I feared the problems with these drives are plentiful.
My problem: Water gets into the oil in the waterpump housing.

What have I done so far:
New impeller kit, with all seals, did not fix problem
Resealed complete upper unit at a local shop, did not fix problem
Changed housing, resealed this, did not fix problem
The housing passes both vacuum and pressure testing, but leaks when I get it in water and the engine runs.

I have had axles inspected as well, and they are in good shape. Also, I can put new oil in, run the engine at idle for one minute , and this will cause the oil housing to overflow with water. In other words it seems like the waterpump is pushing water into the oil somehow.

My local shop cannot seem to understand why this is happening, since it has all new seals, new impeller kit and passes pressure / vacuum tests.

Any of you guys have any suggestions on what this problem could be?

Thanks Fredrik

This is my boat, with the darned drive on it!

 

[CobiaXL]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

Did you use sealant on the 4 bolts that go thru water pump housing?No matter how hard ya try,you cant keep all the water out of upper....I found it easier to check and replace as needed.That and a few other issues and why OMC is gone.

 

[superbenk]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

Did you use sealant on the 4 bolts that go thru water pump housing?No matter how hard ya try,you cant keep all the water out of upper....I found it easier to check and replace as needed.That and a few other issues and why OMC is gone.

Really? I don't get water in either case - ever. I'm not sure how it can pass vacuum & still leak. Are the o-rings around the fill & plug screws ok?

 

[CobiaXL]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

Really? I don't get water in either case - ever.

1 %er

 

[Ottern]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

Hi!

I have used sealant on the 4 bolts.
The o-rings are also brand new.

I think calling this a "leak" might be underdoing it a bit. The drive pushes plenty of water into the oil "tank" to the point that it will overflow after just a minute of running the engine on idle.

Thinking of dumping the price on the boat, just to get rid of it, and let someone else hassle with it..

Thank you for taking time to answer my questions!

Cheers
Fredrik

 

[Howard Sterndrive]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

I was about to ship a 400 upper bare housing I had sold on eBay about 2 months ago..... just before shipping, I noticed the tiniest of hairline cracks right in the impeller housing area.

It's very common for people to leave the 400/800 tilted up over the winter and rain/snow fills that area and breaks the impeller housing- I have changed lots of impeller housings (i.e. full kit). now, I'm going to start inspecting the case there too. I suspect yours has suffered the same fate. It seems the ice can actually crack the case. Why they pass a pressure test, I'm not sure.... but I think the one I was selling had been tested ok in the past too.....but the gears were toast from marginal lube. probably water was in there.

 

[Ottern]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

I have been very strict on draining the engine block, and flushing the system with coolant before winter storage.
Can not account for previous owners though.

I am leaning more and more towards dumping the price on the boat, just to get rid of it.
Cannot be bothered taking the thing off AGAIN, just to see the same problem when I get it back together again.

Thanks for your time!

-F

 

[Howard Sterndrive]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

I have been very strict on draining the engine block, and flushing the system with coolant before winter storage.
Can not account for previous owners though.

that has nothing to do with what I am discussing

 

[Ottern]

Re: OMC Stern Drive 400 - Water in oil - Waterpump housing

Howard Stern Drive:
Sorry.. I also meant to write: and store it tilted down.. =)

Cheers
Fredrik