Tired of chasing water intrusion in Merc...

[EEVW]

Once I water in oil in my 1997 5.7L. Replaced exhaust and riser gaskets once. No problems for a while.<br />Year later, water in cylenders, destroyed starter trying to compress.<br />Mechanic said I had a craked exhaust manifold-starboard side. REpaced it along with new gaskets on both manifolds and risers.<br /><br />Mech says water still coming in. He pulls intake and says he repalced intake gasket. Still more water coming in. Also broke a tooth on flywheel because mech either didn't install starter correctly, or more water in cylinders. <br />All labor and parts paid for up till now.<br /><br />Now he wants to tear everything down and pull the heads...this time I have to pay for more labor.<br /><br />I have spent alot of money and still prblem is not solved. I have "fired"this mechanic and am trying to recoup some of the labor hours.<br /><br />Current status:<br />1. Broken tooth on flywheel<br />2. Water under intale manifold...I pulled off the manifold<br />3. possible head problem, head gasket<br />4. sligtly possible crack in block...very unlikely I think<br />5. No apparent water in oil pan, dipstick level okay<br />6. No rust on port side spark plugs, haven't pulled starboard<br /><br />I live in Savannah, GA area, and all boating is now in salt water.<br /><br />CONSIDERING :<br /><br />1. Rebuilt 350 long block ~ $1700- $2300, depending on rebuilder<br /><br />2. Converting to used outboard with a bracket<br /> ~ cost for transom bracket, fabrication and used outboard unknown<br /><br />I really don't want to keep putting money in the current engine. Any thoughts.<br /><br />REgards<br />SVW<br />Bluffton

 

[jeremyp111]

Re: Tired of chasing water intrusion in Merc...

Finding where the water is coming from can be somewhat tricky. Do you know what cylinder(s) you are getting water in? When you had the exhaust and riser gaskets what were the conditions of the manifolds and risers? Are they original? Is the boat used in salt water? Is it fresh water cooled or raw water cooled?<br /><br />If you are getting water in under the manifold it could very well be a head problem.<br /><br />If you don't know what cylinder(s) the water is in:<br />Pull the plugs, pull the wire from the coil out of the distributor cap and ground it to the engine block with a screwdriver or something metal and crank the engine. See what cylinders water is coming out of.<br /><br />If you know what cyliner(s) the water is in:<br />Pull the heads and have them checked for cracks at a local machine shop. Inspect the risers and manifolds for excessive corrosion and replace if necessary. If they are original and your boat is raw water cooled then it would be a good idea to replace them now anyway since it's all apart.<br /><br />Don't go buy a long block just yet. That's a last resort and only if it proves to be a cracked block (not likely). <br /><br />Jeremy

 

[rodbolt]

Re: Tired of chasing water intrusion in Merc...

hello<br /> no water in the oil just in the cylinders? can you post me back and I want you to tell me all possible points of water intrusion in just a cylinder. tell me that and I will advise you on how to solve this problem. time for a thinking can and a cool refreshing beverage. and at least you have a good seal on the rings.<br /> good luck and post us back.

 

[Walt T]

Re: Tired of chasing water intrusion in Merc...

manifolds/risers/ or riser gasket. Flappers could be gone, and could have a blown head gasket.

 

[EEVW]

Re: Tired of chasing water intrusion in Merc...

I am going to try a DYI and pull the heads. Never messed with anything under the valve covers before.<br /><br />The labor rate for marine mech is $70 and hour.<br /><br />I already have risers, manifolds, intake, carb, distributor,<br />valve covers ,thermostat as well as shift cables and wires.<br /><br />How and where do I have heads, risers, manifolds tested?<br /><br />Oh, I broke a tooth off the flywheel trying turn the engine over. Please don't tell me the entire engine has to be pulled. Can you operate with a broken tooth.<br /><br />Regards<br />Steve VW

 

[rodbolt]

Re: Tired of chasing water intrusion in Merc...

hello<br /> ok you wont even guess for me.<br /> there are limeted ways to introduce water into a cyl. it can come from a crack in the cyl head. normaly due to an over heat or plugged riser for that back. it can be sucked in from a sticking exhaust valve . it can come through a cracked manifold or riser or bad manifold to riser gasket.<br /> I assume this motor is salt water cooled. if so its almost at an age where its not worth messing with. you couild have a blown head gasket. a leak down test will find most head/head gasket problems.no good way to test a riser just toss them in the trash every three years or so. the manilfold you can make a 3/8 thick al plate with a new gasket and air pressure in the cooling hose.<br />well gotta get. wimmins just came home. ill be back

 

[EEVW]

Re: Tired of chasing water intrusion in Merc...

Rodbolt<br /><br />Thanks for the replies. The 5.7L spent 5 years in all fresh water, only 1.5 years ( 15-30 hours in salt).<br /><br />The maifilds and risers have no corrosion!<br /><br />However, if I have to pull the entire to replace a flywheel, then check and maybe replace heads.<br />With motor wit a history of water intrusion, that $1500 long block is looking better and better.<br /><br />Better yet, I'm tempted to sell my Alpha One outdrive ( ~1,000) use that to fabrivate and go with an outboard.<br /><br />Regards<br />steve VW

 

[BRIAN03]

Re: Tired of chasing water intrusion in Merc...

Have your checked the static line in the boat. If all cylinders are being filled with water. All rusted cylinders. Water is being pulled in thru the exhaust at idle. Call any high performance marine exhaust manufacture. They will explain it.

 

[Bondo]

Re: Tired of chasing water intrusion in Merc...

Good Point,BRIAN03......<br />EEVW Seems to have all the other bases covered....<br />I Think the grenerally accepted Static Line measurement is 13" of fall, from the water dump in the risers to the Waterline outside the boat....<br />Of Course, More is Better......

 

[dvarnadore]

Re: Tired of chasing water intrusion in Merc...

First things first get yourself a Haynes chevrolet overhaul manual. It will show you all the basics if you never pulled the heads before.<br />Sounds like you have a blown head gasket. Bring your engine to top dead center and remove the heads and take them to a reputable machine shop preferably one that is preformance oriented (In my experience they do better work)ask the machine shop to check out the heads for any major defects.a valve job and seals, including decking the head will run you about $120. your gaskets will be about$150. to $170. when you reinstall your heads spray the head gaskets with copper coat. doesnt matter if it says on the gasket it doesen't need to be it will ensure an excellent seal,you can find it at any auto parts store. Have all your head bolts laid out and ready to install as the copper coat stays tacky for about ten minutes and don't forget to put thread sealant on the threads of the head bolts.<br />If the heads have ever been removed before and they forgot this step it could very well be why your having this problem. Once you reinstall and run the engine if you still experience the same problem then you have a cracked block. At the very least you know for sure all you need is a short block. Don't sweat the flywheel issue now its not your real problem. <br />Good Luck keep us posted

 

[EEVW]

Re: Tired of chasing water intrusion in Merc...

Capt Dave,<br /><br />But if I have to replace the flywheel, meaning remove engine from boat, pull heads, examine at shop, gaskets assemble everything to an engine that has had water intrusion, put bak in boat...<br /><br />boy seems like getting that reman long block with <br />seems less risky.<br /><br />I don't trust this motor, and darn it is only got maybe 150 hours...90% freshwater.<br /><br />EEVW

 

[airman]

Re: Tired of chasing water intrusion in Merc...

Don't be too crazy about getting a reman long block. A "deal" is usually cheap for a reason. Check out the recent post on rebuilds... I'm not saying that they're all bad but two of my friends on the dock could tell you unhappy stories about their rebuilds. If you need to do this on a budget, consider a local tech school. There are no guarantees there either but at least you won't be out so much cash if you still have problems. You'll probably find the same with an O/B conversion - good ones are big $. The older ones can be gotten a bit cheaper but you'll nearly double the fuel bill and get a 20yr old motor to fight with.

 

[BRIAN03]

Re: Tired of chasing water intrusion in Merc...

You will keep putting engines in this boat Untill you find what the problem is. New engine,reman or rebuilding isnt the problem. The engine isnt the problem its the installation of the engine in that boat. You will keep putting engine in this boat one after another. There is a way to check what you need. When the engine is installed there is measurements for the x dimension ,the static line, and exhaust placement and route. All these demension need to be calculated befor the engine is installed. You have changed everything on the engine. You are guessing and alls you have done is spent money. You havent found the real problem. You need to use science not guessing. You need to prove or disprove what wrong. If there is water(rust) in the middle of the risers and exhaust manifolds it doesnt belong there. If both risers have rust in the exhaust side (in the middle of the risers) If both have rust in them the problem is on both sides of the engine. Its not a head gasket(a blown head gasket would be on one side and usually on two cylinders at the most).Bad manifold or riser one side again. I find it hard to believe both riser or exhaust manifolds go bad at the same time. If all cylinders have rust in them the water is coming in thru exhaust. It not the bad flappers either. Now when you put a new or fresh engine in I feel you should replace the exhaust manifolds and risers and exhaust flappers(shutters) as a cautionary measure. You need to find Why the water is entering the engine thru the exhaust.

 

[rodbolt]

Re: Tired of chasing water intrusion in Merc...

hello<br /> DO NOT USE COPPER COAT.<br /> if this is a saltwater used boat I recommend OMC gasket sealer or quick silver perfect seal or just carefully clean the heads and install the gasket dry. if all the surfaces are true,clean and flat it will seal dry. coat the bolt threads with perfect seal or gasket sealer.<br /> copper and saltwater and other ferrors metals dont get along. it will cause the less noble materiel to go away.if you use never seize make sure its a nickel based not copper based. I agree with bria03 about you need to find out where and why the water came in. sometimes the damage is so severe or widespread that it is impossible to determine. I am currently replaceing a 7.4 340hp merc due to a bad riser. one bad riser fed water to all 8 cylinders then the motor sat for a few weeks . complaint when I got it was it wont turn over. bad thing is the motor was replaced 3 years ago. that is why I always say at 3 years toss the risers by 6 toss the manifolds and the riser. risers are like water pumps, if you ever "need" one odds are you need other parts as well. most modern hulls have sufficient X diminsion as part of mercruisers engineering program. but sometimes due to outside influences the X diminsion will change and no longer be valid. all it takes is one stuck exhaust valve or one time to "disiel" at shut down and some times it can just stick due to sitting. always fog the engine and stabilize the fuel if it will sit longer than 30 days.<br /> good luck and keep posting

 

[SS MAYFLOAT]

Re: Tired of chasing water intrusion in Merc...

Do you trailer this boat? Launching and loading each time you use it? I have noticed that a few times of launching the boat too fast can force water back up into the cylinders. Then on steep ramps, while loading I have had water intrusion because it caused the static water level to go way below what it should and bingo, water in the cylinders.<br /><br />Just a thought.....

 

[BRIAN03]

Re: Tired of chasing water intrusion in Merc...

The new style flappers (shutters) close realy well if installed correctly. Water will not come in that way. If you launched the boat and water came in the cylinders the engine would hydo and you couldnt start the engine. Thats not where the water is coming from.

 

[SS MAYFLOAT]

Re: Tired of chasing water intrusion in Merc...

Brian, what if the flappers are bad? I know on sudden rushes of water they will do their job, but if the boat is submerged for a length of time, say 4 or 5 minuets, the flappers may not shut off the water 100%.<br /><br />If this has been an on going problem and the backflow flappers haven't been checked, could it possibly be the problem? You did mention if they were installed correctly, so you can say that if they are not working properly, this could cause it? <br /><br />In my line of work, you must not assume that all componets are doing their job until they have been checked out for proper function.<br /><br />Just a thought, not looking for an argument, just a solution to the problem.

 

[BRIAN03]

Re: Tired of chasing water intrusion in Merc...

The only time I have see the flappers gone is when the engine has been over heated. As for a rush of water from putting the boat in the water. I think you would need to be going 30 mph. To force water up the exhaust it would have to go up the y pipe and up the top of the riser and go in the exhaust manifold and find a exhaust valve thats open. There is a pocket in the exhaust manifold that will hold water. I do believe that if the boat is on plane and you lost the ignition and the engine was still rotating(the flappers are open) to a stop the water behind the boat could have a chance of getting to the cylinders. The difference is the engine is rotating and there is a wave of water behind the boat. Thats why the exhaust flappers are there. If the engine isnt running and you back the boat in the water i think the chance of water making it to the cylinders is slim. If water did make it in the cylinder and didnt hydro the cylinder and you started the engine and there was no damage. Once the engine started the water would be expelled. They have redesigned the flappers(shutters) for water injestion not water being pushed up the exhaust. The new shutters fit really tight in the y pipe.