Water in Oil and Cylinders
Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: Common Questions
Forum Discription: Visit here first for common questions regarding your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=28922
Printed Date: November-24-2024 at 11:44pm
Topic: Water in Oil and Cylinders
Posted By: SKI NH
Subject: Water in Oil and Cylinders
Date Posted: February-06-2013 at 9:17pm
|
Hope someone can help. I have an 85 SN 2001, 351PCM engine. The boat has always run perfectly and started easily but one day last Summer, I suddenly ended up with water in the cylinders which made the boat first hard and then impossible to start due to hydraulicing. Checked the oil and found water there also. This all seemed to happen overnight. The engine always ran at 160 degrees and definately did not overheat. I pulled it apart and checked everything out, pressure tested exhaust risers and heads and found nothing obviously wrong except for one corroded exhaust valve seat. Head gaskets looked fine. Did a complete valve job and reassembled, ran on land but not in the lake yet. The boat stays in the water tied to the dock all summer and I'm wondering if heavy wave action could have forced water up the exhaust? There are rubber flaps but they would tend to open, I think, on the downstroke of the waves. This also happened to my last boat (350 Mercruiser) which makes me suspicious. Has anyone seen this before? I can dock the boat with the bow out but that is a pain. Appreciate the help. ------------- SKI NH |
Replies:
Posted By: 8122pbrainard
Date Posted: February-06-2013 at 9:45pm
|
Steve, I doubt that wave action forced water into the engine. With riser type manifolds plus the rubber flappers I have to say it would be nearly impossible. You didn't mention doing a compression test before you pulled it apart. How were the gaskets and their mating surfaces between the manifolds and risers? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 74Wind
Date Posted: February-06-2013 at 10:48pm
|
My friend had this exact issue with his 73 Century Coronado, water entering thru the exhaust and then directly into the engine/cylinders. With his, however, there is very little rise from the transom to the manifolds. I'm sure Pete is correct that it's not likely this could happen with your modern setup/risers. ------------- 1974 Southwind 18 1975 Century Mark II |
Posted By: SKI NH
Date Posted: February-07-2013 at 1:37am
|
Thanks for the replies, guys. A compression test was not done. The exhaust manifolds and risers were tested as units so the gaskets should have been good. In any case, all is new now. I don't se how I could have gotten water in the cylinders and oil as well from only one bad exhaust valve seat. Only other thing I can think of is the intake manifold but that looked fine. The cooling system was pressurized with a garden hose and water did enter the cylinder with the bad valve seat but when the engine is stopped, some valves will always be open so I guess I don't quite understand the logic there. I'm not a mechanic but did some of this work myself and the rest was done by a reliable mechanic. I'm thinking of trying shrouds about 4 inches long aound the exhaust tips and flappers to help keep the flappers closed as the boat comes down off waves when it is tied up. The lake gets pretty rough in front of my house on weekends. Its the only other thing I can think of other than backing it in every time. ------------- SKI NH |
Posted By: TRBenj
Date Posted: February-07-2013 at 12:22pm
|
I suspect the rusty exhaust valve seat is a symptom of the water intrusion, not the cause. Water should not be entering the cylinders in the first place. When you tore it down, did you note any signs of where the water was coming from? Any water in the runners of the exhaust manifolds? Any rusty water tracks in the valley that would indicate an intake manifold leak? Which exhaust valve was it? How did you pressure test the exhaust manifolds? Presumably the heads were magnafluxed when you had the valve job done? Im not entirely clear- what is the current state? Freshly assembled and run on the hose with no issues yet? Or are you seeing more signs of water intrusion since the reassembly? You may still want to do a compression test- a failure would most likely indicate a cracked block. I highly doubt water is coming back in through the exhaust ports. A few people have seen the engine turn backwards a revolution or 2 upon shut down, which can be enough to suck water back into the engine and hydrolock it (I havent heard of any credible reason for why this happens though). ------------- |
Posted By: SKI NH
Date Posted: February-07-2013 at 4:52pm
|
No obvious rust tracks anywhere. The heads were magnifluxed and found good. Head gaskets had no obvious bad areas. You are right, we should have done a compression test first thing, I suppose. That will be first if it does it again, for sure. I do remember the engine backfiring when starting it that time. Can that suck in water? What causes the backfire? Status now is: All reassembled with heads planed, all valve seats ground and all new marine gaskets ( heads, manifolds and exhaust risers. The mechanic tested the exhaust manifolds and risers. Not sure how as I missed that part but trust what he says. The watery oil was drained and fresh petroleum oil filled. The engine was run up with the garden hose for half an hour. No water anywhere. Started and ran perfectly. Drained that oil and refilled with AMSOIL as always. I now have to wait for Spring to get it back in the water. You guys have all talked me out of thinking the water got in through the exhaust outlets.Can't help thinking about that backfire. ------------- SKI NH |
Posted By: Dadof8
Date Posted: April-28-2013 at 9:10pm
|
SKI NH, Water in Oil and cylinders. That's very scary to hear as I just pulled off the top of the exhaust manifolds on both the port and starboard sides. Plugs 1,4,and 8 showed signs of water contact. The Starboard side manifold show signs of rust, where as the port didn't, but cylinder 8 still had water contact. Of course the oil was nice and milky. Any of this sound familiar to anyone? I, like everybody doesn't want to pull off everything to find out its simply the exhaust manifolds need work. Help! ------------- Make each day on the water last as long as possible. Unless it's because the boat died. 77 Ski Tique 302 Ford |
Posted By: 84SNautique
Date Posted: April-29-2013 at 12:37pm
| Sounds like internal cracks to manifolds...they get heat soaked after shutdown and cracks will open...almost impossible to see or find while cool. |
Posted By: backfoot100
Date Posted: April-30-2013 at 1:13pm
Not scary at all. Fairly common problem on here. Need more info on how you found the water in the oil. What the conditions were. How it was running at the time. Did it overheat? Has it ever overheated? Does it run in salt water or has it ever run in salt? How many hours on the engine? What maintenance has been done? What engine is it? Most common problem is exhaust manifolds either cracked or riser gasket shot. Is there any signs of water tracks on the outside of the exhaust manifolds? You pulled off the top of the exhaust manifolds. Why? Standard gasket replacement or troubleshooting the water intrusion. Other potential problems are cracked head, cracked block or blown head gasket. Have you done a compression check or leak down test? More specific info would help out a lot. By the way, welcome to the site. I think you'll find a lot of helpful info here. Pics and more info about your boat are always welcome too. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Dadof8 wrote:Posted By: SKI NH
Date Posted: April-30-2013 at 9:36pm
|
Not sure about Dado but in my case, to answer some of your questions, engine is PCM 351 with about 750 hours. Never a problem with anything before this. Never run in salt water. The boat was running perfectly up until the day. When starting after sitting at the dock for a week, it was harder starting than usual. Had a pretty severe backfire at that time and I've been wondring if that had anything to do with it. Finally started and ran but was eratic. after shutting down, it locked up and after pulling the plugs, found water in a couple of cylinders as well as in the oil. Checked and rebuilt the heads and manifolds and runs perfectly again just in testing onshore. Not in the water yet so time will tell. Any thoughts appreciated. ------------- SKI NH |
Posted By: backfoot100
Date Posted: May-01-2013 at 12:59pm
|
I suspect the backfire would have been the result of water in the cylinders not the cause of it. You've taken care of any of the potential issues that could have caused your problem without confirming which one was the problem to start with. You said the mechanic tested the manifolds. Was that before or after the gaskets were changed? If it doesn't have any issue now, run it and be well. If it happens again, some more investigation would confirm the problem before tearing it completely apart. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |