Uh Oh...Water in Cylinders

[mike7a10]

I have been running my old A-4 with raw water cooling for 4 years and have never had water in the cylinders. I have also never had the need to close the seacock.

Today for Mothers Day my wife and I were going to go for a cruise and after starting the engine I found a water leak where the cooling water enters into the water lift muffler. The 1 1/4" pipe had rusted through and after removing all of the fiberglass tape it was apparent that I needed to build a new exhaust "hot" section from the exhaust manifold to the water lift.

Went to Home Depot and got all of the parts. The engine started fine but I had a few minor leaks in the system that I had just built. A little while later I could not start the engine. Futzed around for a while until I pulled a spark plug and bingo...found water in the cylinder closest to the exhaust manifold flange (#3 firing).

After freaking out I closed the seacock and turned the engine over until most of the water had been blown out of the top. The dipstick shows signs of a tiny bit of water in the oil. It put a lot of MMO in the cylinders, poured a little raw gas in the cylinders and fired her up. After a bit of coaxing the engine came back to life I opened the seacock and I ran it for about 30 minutes. It ran great.

I then intentionally waited 25 minutes to see if the problem returned and of course as luck would have the cylinder closest to the exhaust manifold exhaust flange was again full of water. I repeated everything but after getting her running again I turned it off with the seacock closed. I am going to start her up tomorrow and I am planning on changing the oil several times to remove any water.

What is going on? Did the new "hot" section of the exhaust cause the water to siphon easier because it is clean and new? I did move the hot water heater hose "T" to the "front" of the loop (closest to the exhaust flange). Do you think the water from the hot water heater is draining back into the exhaust manifold? That seems a bit of a stretch but since that was the only thing I changed from the original set up it seems a likely possibility. I am thinking of changing that setup and moving the hot water "T" back to the "back" of the loop where it originally entered directly into the water lift muffler.

In reading all of the years of people writing in on the forum about water in the cylinders it seems like a lot of people shut off the seacock (before?) stopping the engine and reopen it once the engine has been started. Like I mentioned at the beginning I have never had to do this before and I will of course do this if necessary but that is a bit of a pain. I am truly stumped.

In the end, is it common practice to shut off the seacock prior to shutting down the engine and then reopening once the engine has been started? As always I very much appreciate any help/info I can glean. This website (and Don) have saved me many times in the past. Best regards, Mike

[gfatula]

Did you drain the water lift muffler?

George

[mike7a10]

I did not drain the water lift muffler. I have not heard of this before. Should I drain it prior to rebuilding the hot portion of the exhaust system?

[msauntry]

This is an easy one...

The water "T" goes in the back of the hot section away from the flange, otherwise it drains straight into your engine as you've found out. Move it back to where it originally was and some oil changes will take care of the water in the oil. No harm done.

[MikeB.330]

In late fall and early spring I have the water valve shut off prior to starting the engine. During the colder times of the year I do this just because it may take a little extra cranking to get her going.

From about this time of the year until early fall I open the valve before starting. If the engine doesn't fire with the first touch of the starter button I shut off the water valve before starting.

[mike7a10]

Thanks guys. MSauntry: As you saw that is what I suspected. Thought I was pretty smart on this one but it bit me. I will be rebuilding the section this afternoon and plan on moving the T back to just above the water lift muffler. I believe that this should solve the problem. I will repost once I determine if that is the "fix".

Mike

[mike7a10]

Update

Thanks again to everyone. I was able to rebuild the exhaust hot section and placed the "T" back where it was originally and this seems to have fixed the problem. I am keeping a wary eye on it...

Interesting thing happened though. After I got the engine running again I noticed that the timing had to be reset. I am hoping that this indicates that the exhaust was restricted enough to have been robbing me of some power.

I'm not sure when I can take her out for a quick spin but I am hoping to be able to do that this afternoon.

I appreciate everyone's input. Once again Don's website has helped me out!

Mike

[sastanley]

Nice work Mike. Especially smart to get all the water out right away to avoid rusting and internal damage.

There were reports from the P.O. of my Catalina 30 that the engine had been drowned (water in cyls #3 & #4) due to overcranking (engine not running) and the water intake open. This boat had a very short (probably original) hot section and as soon as the muffler filled up (or more likely still almost full from the last running) the water backed up the hot section and dumped into the cylinders. I rebuilt my hot section this winter, and made it as high and as long as possible, probably doubling the new hot section's length as compared to the old one, and added some uphill piping to help keep the water out.

I agree 100% that the relocation of the water injection probably allowed the cooling water to easily dump into the cylinders.

For reference, here is a pic of my old hot section (tape removed) & a pic of the new section dry-fitted, prior to final assembly. I tried to get the water injection as far away from the manifold as possible without completely redesigning the rest of the exhaust system.

I also got a tip from another website to use Permatex as a sealer in the pipe threads. I used the No.2 which is in a tube and a little thicker, but similar to the Aviation Brand (No. 3) Permatex that Don uses extensively. I think either would work.

[mike7a10]

Update II

I am finished with this job... It has turned out to be quite the job too! After moving the "T" to the back of the loop (closest to the water lift muffler intake) the problem was eliminated. But I had created another problem.

The engine would start fine, idle fine and then die when I gave it more throttle. The engine had gotten wet with a fine spray of seawater from the intial exhaust leak and after conferring with my marine mechanic buddy I was confident that there was condensation on some of the exposed electrical parts. So I changed the distributor cap, rotor, coil and spark plugs but the problems continued. I changed out the gas/water seperator filter. I changed the fuel lines. I then checked the cool section of the exhaust beyond the water lift muffler for restriction but I could find nothing. What was even more maddening was that the engine got to a point it would'nt even start.

The only thing left was the fuel. And sure enough my initial exhaust problem had caused a carburator problem...

The (new) carb had sucked in some seawater through the manifold and this in turn caused the floats to stick in the closed position. To compound this I had added a fuel additive named "Seafoam" to the gas. I don't know what exactly happened but I dropped the carb and sprayed it thoroughly out and reattached it. This did not fix the problem so I dropped it again and tore it open (and found the sticking floats). Hooked it back up again and it ran great...for about 3 minutes and started sticking again to the point it would not run again.

I dropped the carb again and tore it open and cleaned it. But before reattaching I drained all of the fuel out of the tank (I had to pump it out by hand with an inline pump...12.5 gallons...that was fun!). I then changed the fuel filter (again) and put fresh gas into the tank. I got her running and we had a nice day sailing with our out-of-state guests.

One benefit from pumping out the fuel was that I found no water in my 34 year old aluminum tank and just a little crud. At least I know that the tank is clean!

It is now running nice and smooth but is now hard to start. Once she gets going it runs great. I have noticed that it runs better with the choke engaged so I believe I have the carb set too lean and I am going to fine tune it this coming weekend after our guests have departed.

The moral of this story is that all of this could have been prevented if I had placed the "T" in it's original place. It is amazing that this one minor (or so I thought) change would cause 5 days of more work and worry. The other lesson learned is hang in there...keep plugging away and eventually you will most likely figure out the problem.

Again thanks to everyone and to Don for a great website. Though I don't often write in, over the years I run to this website anytime I have a question about the A4. I have saved thousands of dollars that I would have spent with marine mechanics by doing all of my own work over the years which would not have been possible without the support of this website.

Best regards to all...

Mike
S/V Plan Sea

[roadnsky]

Mike-
Nothing feels as good as hearing her fire up after fighting a nagging problem.
Congratulations on persevering and succeeding!

[rigspelt]

The (new) carb had sucked in some seawater through the manifold and this in turn caused the floats to stick in the closed position.

Excellent anecdote. Thanks for sharing this one, and congrats.