Mercruiser Alpha 1 water in oil

[hooked514]

Need help, took boat out the other day rode for about 1 hour, temp and oil pressure normal. came to a stop and dropped anchor for a couple of hours when I went to start it up the starter was clunking and grinding but it eventualy started and ran normal I took it to the closest dock about 10 minutes and turned it off. Pulled the dipstick and found water in the oil. Pulled the plugs and found water in pretty much all the cylinders. Cranked the engine over and got the water out on top of the pistons and changed the oil. My question is on a 1993 5.7 mercruiser with 371 hrs on it. How to I diagnose what went wrong and is it worth trying to fix. Thanks, Tim

[ss3964spd]

Does the engine still run Tim?

Most likely culprit are the exhaust risers - especially if they have never been changed.

Dan

[hooked514]

Hi Dan, after we changed the oil and plugs we put the boat back in the water and it was making that noise like it was still hydrolocked. After I kept bumping the key it started but cut out when I throttled it down. I did not want to keep trying it and do damage. With the plugs out it cranks fine. How do you tell if it is risers ? should I replace them along with the manifolds? Thanks Tim

[ss3964spd]

Only way to tell if it's the risers, Tim, is to take them apart.

At this point the only thing you really know is water was getting into the cylinders. Oh-oh, getting into ALL the cylinders?

Dan

[hooked514]

Dan, The port side cylinders had most of the water. There starboard side both center plugs were a little wet. Tim

[ss3964spd]

So, it's not going to be the head gaskets since so many cylinders were affected. I think the GM engines of that time had some issues with intake manifold gaskets but, again, with so many cylinders affected, probably not that either. No cylinder head cracks, either, since so many affected. Almost has to be the risers Tim, and is where I would start.

Dan

[hooked514]

Thank you so much Dan, I will pull the risers should I pull the exhaust manifolds as well ? Tim

[ss3964spd]

Pull the risers first Tim. Once they are off you'll be able to determine if the manifolds also need to be replaced.

Good luck - take pictures!

Dan

[oneradride]

Also, might go without saying but water does not compress and you WILL snap teeth off the wring gear if you keep trying. Only putting this out there because I've done it.