MerCruiser 135HP Water in Oil/Compression OK

[DarrenL]

I have a 2005 Glastron MX 175 with the 135hp Mercruiser I/O. 2 weeks back I noticed water in the oil. Oil has since been changed, compression test done on the engine and then the engine was run with a hose for about 45 minutes with no water seeping into oil.

Took the boat in the lake this past saturday, drove it for about 10 minutes, stopped to check the oil and there was water in it again. I don't believe it could be a head gasket or crack in the block because the compression test was ok.

Could water be coming back through the exhaust system? I believe there is some type of valve in the system. Any other ideas?

Thanks,

Darren

 

[Bondo]

Re: MerCruiser 135HP Water in Oil/Compression OK

I don't believe it could be a head gasket or crack in the block because the compression test was ok.

Ayuh,... A Compression Test has Nothing to do with a Cracked Block...
You need to air Pressure Test the Cooling System...

 

[DarrenL]

Re: MerCruiser 135HP Water in Oil/Compression OK

Ok, I did an air pressure test on the water cooling system. It held at 8 psi no sign on a leak anywhere. Any ideas from here?

 

[JustJason]

Re: MerCruiser 135HP Water in Oil/Compression OK

put in 30 to 40 psi. because thats what the water pressure is when it's running.

 

[DarrenL]

Re: MerCruiser 135HP Water in Oil/Compression OK

Ok, thank you. I will re-test the system this weekend.

Darren

 

[MercBravoIII]

Re: MerCruiser 135HP Water in Oil/Compression OK

How watered down was the oil? Have you overheated the engine ever? what was the readings from your compression test? alot of people say yea my readings were good, hoping to find the a differnt answer to thier problems. Some Possible ways water can seep into the crankcase are by Intake Manifold, Head Gasket areas. When you first found water in oil did you previsouly run the boat?

 

[DarrenL]

Re: MerCruiser 135HP Water in Oil/Compression OK

I believe I may have figured out the issue. I did the compression tests and everything was ok, did a cylinder leak down test up to 75 psi and each cylinder held. I always took apart the exhaust a looked at the flapper valve and that was ok and I checked the cooling system and it was ok. So, I changed the oil and filter again and have run the boat and have had no issues with water in the past week.

About a week prior to the water issue I was having problems with my carburetor. While up on plane, the engine died out on me and the boat came to an abrupt stop. I think that I may have had water pass through the exhaust valve when the engine shut off. The first time on the lake after I had the carburetor problem is when the water showed up. I am going to keep an eye on the oil but I am hoping thats it.

Thanks for the help,

Darren