Water in cylinders. Yikes!!!

[Bratcher4079]

I have an 89 Valiant VIP with a GM v6 motor. I had a previous thread that was regarding water in the oil and lifters tapping. Here's the current update that I need advise on. I had a mobile boat mechanic come out and here is what he found. Both of the rear cylinders have water in them while running on muffs. This is the back cylinder on each side. We pulled the plugs and water came out of the two rear cylinders. Water is in the oil pan too. The mechanic thinks both head gaskets are leaking. All cylinders had 150 psi pressure. I'm thinking what is the odds of both head gaskets going at the same time. Would the intake manifold leaking make more sense? How can water get in both of the rear cylinders at the same time? They want 1300.00 for a head job. What would my best course of action be. Please advise. Thanks...

 

[bruceb58]

Re: Water in cylinders. Yikes!!!

I would do a pressure test of your cooling system before I did anything else.

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

I'm new to boating. Can you explain how to do the cooling system pressure test?

 

[Reinell-BRXL-191]

Re: Water in cylinders. Yikes!!!

I would first take the intake manifold off, you should be able to see if there is any freeze damage or cracks that would allow water in to the rear cylinders - if you don't find anything.. then you have to move to the heads.. I personally think that it is very unlikely that 2 head gaskets would fail in the same place at the same time... I am voting intake manifold

But it is obvious that you can't run the engine the way it is, so no point in not taking it apart... You have to find the source before you can determine a cost to fix it...

 

[bruceb58]

Re: Water in cylinders. Yikes!!!

If you did take off the manifold, no guarentee that you would see cracks that allow water to enter the cylinders. If the water was entering the cylinders this way, the crack would be between the water passage and the intake passage which you would not be able to see. Any cracks that you see on the underside of the manifold will be putting water directly into the crankcase.

Before you take anything off, do a pressure test. if it passes the pressure test, no need to take off the intake manifold.

Pressure test is easy to do. Basically, block off the hoses going to the exhaust manifolds. You can just take the hoses off the manifolds and loop them back to eachother using a piece of pipe and hose clamps.

Buy a gas pipe pressure gauge that includes a schraeder valve and rig this up with some pipe, adapters and hose and attach this to the thermostat housing where the hose that brings water up from the drive.

If it passes the pressure test, I would think it could possibly be bad manifolds/risers. If you have the batwing manifolds(probably do) you won't have risers. You would only get water into the cylinders once the engine was turned off and water that had leaked into the exhaust passage of the manifold could go through open valves into the cylinders. Water that sits in the cylinder can then seep into the crankcase over a period of time.

This boat used in salt water ever?

 

[Idlespeedonly]

Re: Water in cylinders. Yikes!!!

I doubt it is the intake. There are no water passages in the back of the intake. Possible to have a bad intake gasket on both sides though. I would look at the riser gaskets. But I would pressure test before I removed anything.

 

[bruceb58]

Re: Water in cylinders. Yikes!!!

I doubt it is the intake.

I was thinking the same but I think there is a small possibility that water could enter the intake chamber and roll towards the back cylinder if the boat is run on the trailer with the bow high.

 

[Idlespeedonly]

Re: Water in cylinders. Yikes!!!

I maybe wrong but i dont think the front coolant passage shares a common wall with any runner. But stranger things happen.

 

[Reinell-BRXL-191]

Re: Water in cylinders. Yikes!!!

The rear water passages in the heads come up to the manifold, they don't share a cross over.. the front cross over has a passage that expands out to the walls of the front 2 runners right in the center of the plenum... after thinking about it, I am starting to think his problem may be in the risers, the possibility of the intake gaskets failing and it not pouring water in the the lifter valley is pretty slim - but he is saying he is having a lot of water in the oil... water doesn't get by rings very easy unless they are damaged.. so, its kind of got me scratching my head.. but I am sure we will all find out shortly what it is...

Of course I am assuming this is a stock OMC manifold on the stock engine for the year of the boat.. if someone has installed a newer EFI engine in to the boat, there were models with rear water passages (normally truck/SUV)

 

[bruceb58]

Re: Water in cylinders. Yikes!!!

He probably has batwing manifolds if he is using stock OMC manifolds still so no risers.

Some water, not much, can seep by the rings. I had manifolds fail and got a tiny bit of water into the oil causing it to get milky.

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

Thanks for all of the replies. I do have the bat wing risers but i have no idea of the age of them. The intake manifold appears to be a stock omc. It's not EFI either. I dont know if the boat was ever in salt water. I get about a quart of water in the oil pan (reading the dipstick) in about thirty minutes of running on the muffs. After pressure testing the manifold if it's ok should I then pressure test the exhaust manifolds. If no issues there where would I go next. I'm starting all of this saturday and would like to have all of the what iffs answered so i can proceed without delay. Thanks to everyone for there help.

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

What is the PSI for the intake test and how long should it hold the air pressure for testing.

 

[Toypirate]

Re: Water in cylinders. Yikes!!!

There is a mercruiser vortec V6 intake manifold that has a water cavity in the center above the lifter valley, Identifiable by the drain plug on the front starboard face where the crossover passage is. Check it out.

 

[Toypirate]

Re: Water in cylinders. Yikes!!!

take it up to 20 psi, it should actually hold to 40 but dont chance that, if it holds for 15 min. theres no leak in what was pressurized.

 

[bruceb58]

Re: Water in cylinders. Yikes!!!

After pressure testing the manifold if it's ok should I then pressure test the exhaust manifolds.

You can't pressure test those exhaust manifolds. You could take them off and see if there is signs of water/rust at the exhaust ports. There should be ZERO water in the exhaust ports between where it bolts up to the head to where it exits up at the top of the wing.

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

I just completed the pressure test. I pressured it to 20 lbs and let it sit for 20 minutes. It only lost 1 pound over the twenty minutes. It appears to be ok. Where should I look next?

 

[Howard Sterndrive]

Re: Water in cylinders. Yikes!!!

do your manifolds have removeable risers?

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

Intake manifold pressure test is ok. For my next test I connected a water hose to the the incoming hose line from the outdrive to the thermastat housing. This pressuzied all of the motor water passages. I pulled the spark plugs and slowly rotated the motor by hand. Water began shooting out the left rear cylinder. As I continued to rotate the motor the rear cylytnder quit leaking an the second cylinder be began leaking water. Rotated again and front cylinder sprayed water. All of the cylinders on the left shoot water out of them when the motor is rotated. The cylinders on the right does the same but the water has much less volume. More of a occasional trickle. So what's next. The intake monifold held pressure during it's test. I couldn't see any water spraying into the motor while looking into the holes in the cylinder heads (valve covers were off). Should I have the bat wing exhaust manifolds magnafluxed to check for cracks. Or am I looking at two head gaskets or a cracked block. Please advise and thanks again for everyones help...

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

The risers are the batwing style...

 

[Bratcher4079]

Re: Water in cylinders. Yikes!!!

I disconnected the two water hoses that go from the thermastat housing to the exhaust manifolds. I Then tied to two thermostat hoses together to make a loop. Like I did for manifold pressure test. I turned the water back on and did not have any water coming from any of the spark plug holes. This would leave me to beleive the the water must be coming in from the exhaust manifolds and dumping water in the the cylinders from the exhaust valves. Does this make sense to anyone?