1996 787 water in cylinder

[two80mine]

I have a 1996 Challenger with twin 787's. This is my first post. I need some help trying to root cause water in my cylinder. This happens randomly throughout the summer, I cannot establish a trend or pattern. The boat is kept in the water all summer. It is the white motor and the pipe plugs have been tig welded. So here is what is happening. I will go to start engine it will start to turn over then hydro lock. I will remove plugs, turn over engine with my fingers over plug holes to get water out. I will let it sit for about a half hour after plugs are dry and it start and run fine. Like I said sometimes this happens and sometimes it doesn't. I am at a loss for what it could be. Please help :banghead::banghead::banghead::banghead::banghead: Thanks everybody, this is a great site and I have learned so much.

 

[Coastiejoe]

First,, be VERY careful doing the finger over the hole thing. Water, (gas and oil) are not compressible. So, it WILL come out of the hole due to you plugging the hole. The issue is, it can easily tear your skin open and inject under high pressure all kinds of nasty things...

Is there water in the hull?

This water HAS to be coming from somewhere. If I had to guess, it is collecting in the lower block and when you crank the engine, it gets sucked into the cylinder.

If you simply can not find where it is coming from, then you need to change things. Change or use a different cover. Pull the boat so it does not sit in water, ect ect. With a change, see if the issue goes away.

 

[two80mine]

It does it even with a dry bilge, that is why I am confused. Can the RAVE, head cover, and or exhaust gaskets cause any issue like this? The one time I did have water in bilge it started fine for 2 weeks straight. It has done it after I have put boat back in water when I took it out to clean algae from the hull. Boat was out of the water for a few days.

 

[Coastiejoe]

Do you have some pics of how the boat is stored, what if any covers, ect ect...

 

[two80mine]

No I do not, and I do not keep boat covered in the well. I have an auto bilge

 

[Coastiejoe]

No I do not, and I do not keep boat covered in the well. I have an auto bilge

To be clear, a "Well" is basically a garage on water, yes?

Just trying to figure out how water is getting into the engine. If there is NOTHING that is allowing it to enter externally, then there MUST be a crack or bad gasket, such as a head gasket for example.

 

[two80mine]

A well is a slip in marina, and yes I agree it is possibly a gasket, just don't know which ones to start with .

 

[racerxxx]

How is the boat winterized?

 

[Coastiejoe]

A well is a slip in marina, and yes I agree it is possibly a gasket, just don't know which ones to start with .

I was wondering if it was covered or just sits at a dock kind of thing?

I would think you could pull the head and get a pretty good clue as there should be a rust line if it is up top.

Does the water come out of both plugs or only one?

 

[two80mine]

Usually just out one cylinder, I believe the one to the rear of boat. I don't know how the boat was winterized in the past. I followed the manual this year when I did it.

 

[Coastiejoe]

If it were mine, I'd be pulling the head. If the cylinder is cracked it will likely be VERY clean from the steamed water that happens during combustion.

 

[racerxxx]

Gonna be tough when you pull that head. I can guarantee water will drop in the cylinder. Honestly, the ideal way to do it is to pressure test the cooling system. If that can't hold pressure then it will show up. It's a ton of work just to check it out. The base gasket could also have rotted out. In the front of the gasket they're thin and and water will lay in a pocket ALL the time. I had one that did it, luckily it pushed out, not in. I have a Challenger coming in cause the base gasket pushed out.



If you locate the 4 small holes in a square pattern, those cut outs to the left and right are where water will lie all the time. There is a chance that is where the leak is bridging into the large cut outs above them.

 

[two80mine]

I am gonna pull the cover and start from there. I really appreciate the advice. I will keep you updated on the progress. Thanks again, Matt.

 

[Sandman251]

Not to be a stickler....but there is no way you could own a 96' challenger with twins. Anyway good luck with your problem.

 

[two80mine]

Now I am going to double check my registration.

Not to be a stickler....but there is no way you could own a 96' challenger with twins. Anyway good luck with your problem.