99 Indmar 350 EFI Water in Oil. Troubleshooting help...

[tysidor]

I have a 1999 Malibu Response with an Indmar 350 EFI. I am by no means a mechanic but I understand the basics and I am trying to get some guideance on where to start. I am having someone else do the work and am trying to point him in the right direction. Engine oil becomes milky after very little run time. At this point multiple things have been done to the engine.

1. We have pressure tested the block. No signs of a leak.

2. Replaced Intake Manifold.

3. Replaced head gaskets and head bolts last year. But since that time the boat overheated due to an impeller failure. Should we look in that direction again?

What steps and in what order would you suggest us to troubleshoot. Your help and guideance is very much appreciated.

Thanks in advance!!

[Bozboat]

was the block pressure tested before or after it overheated?

[plano86skier]

If the boat overheated, it really sounds like head gaskets are leaking water into the oil. Water in the oil is what make it become milky. But since you have replaced the head gaskets before, you should be able to again without too much problem.

[tysidor]

Block was pressure tested after the overheat. Did a leak down and everything seemed to be withen tolerence. Would the head gaskets start to lead after the engine is heating up? Maybe even a warped head?

Another thing to mention is that there is a bunch of oil below the engine where the drain plug is. Is the a sign of anything in particular?

Edited August 13, 2012 by tysidor