5.7L bravo 1 Water in cylinders 1 and 3 after overheat need advice

[mr300z87]

First some back history. Three weeks ago my wife and I went out for an evening sunset cruise, my lack of attention to the missing channel marker caused me to suck some sand through raw water pump into the water hose located under the engine and caused an overheat This is a BRAVO 1 with the belt driven pump. I shut the engine off before the alarm rang at 180 degrees, re stared and it quickly rose to 200 degrees and the alarm sounded I shut it off immediately . That night night I go towed, did some quick troubleshooting in the dark and determined no water going to engine. The next day I took off from work went to the boat cleared raw water hose and check raw water pump (Bravo 1) re assembled and all good. Ran normal temps 140 at no wake and 150 at 3000 rpm cruise speeds. I did run it a little harder than I normally do with no issues. The wife and I took her out again that weekend with no issues. The boat then sat all week and last weekend before leaving for our family beach vacation (no boat), she gave me a hard time staring which it never has before, but it started and seemed to be running fine. So we went out for a short cruise and all was well, and I again ran it hard (no wife) for a short burst, then about half way through the no wake area approaching the marina it developed and miss. Since we were getting ready to leave I only had a few min to troubleshoot. I figured it was probably carb or fuel related so I ordered new fuel filter to be installed upon returning home. So hear I am

Got home this morning, we had a great week in Ocean City NJ, and I figured I would go to the boat to do some more troubleshooting. As I always do I checked the oil and the gear lube, which looked good so I went to fire her up and much to my dismay it went clunk and the engine turned only a couple degrees and stopped. After a couple of bad words I determined that it was hydro locked. I pulled all 8 plugs and found water in cylinders 1 and 3 only(thankfuly my mainra in all the way up the Metedekonk river and is fresh water). After more bad words and a lot of staring. I continued to crank engine until no more water came out, I then sprayed WD40 in the cylinder and cranked it again them more WD40. Put all the plug back in cranked it one more time and left to go home and cry. LOL

I am pretty confident that is it not a riser/elbow or back wash issue because last year I updated the manifolds and risers to DRY JOINT type and the elbows are well above the water line at least 4 inches above Mercruiser minimum.

My plan of attack for tomorrow when I hope to get a helper is to do a compression test which I would assume would be low on cylinders 1 and 3 if it was a blown head gasket. Does any one know the marine felpro #? Also if it is the head gasket should I do both? In the water or out? What else should I look for? Would a mild overheat like I had be the cause? FYI my engine is a 5.7L Bravo 1 330 or so hours, the serial # is in my signature file. Thank in advance for any advice. Now is time for BEER and more crying. I have no time for this I want to go boating!!!!

Mike

 

[Grub54891]

I think you are barking up the right tree. A compression test will tell you a lot, And possibly a leak down test also. The gasket set comes with both gaskets, ya may as well use them. I'd do the work, preferably in the garage, out of the sun, and tools handy.

 

[mr300z87]

Plan as of now it to go to the boat with my friend and the trailer early tomorrow, do a compression test and then most likely bring her home for repairs. Unfortunaly I have no garage so I will still be outside. I found this kit no felpro # 17214. Is the the right one? Merc wants stupid money for their gaskets, probably made by felpro and I did not even get to the intake gaskets yet. Lol

 

[Rick Stephens]

Grub idea of a leakdown might save you some misery of missing anything later on in the repair.

 

[thumpar]

One thing to check is you shutters. They are probably missing. It wouldn't take much of a wake to push water up the exhaust.

 

[mr300z87]

This morning we took the boat out of the water and it brought home. There was no more water in the Cylinders (I drained the block and manifold yesterday). I ran a compression test with not so great results

After my cold test I put it on the hose and ran it to normal operating temp and here is the weird thing it ran fine or as good as it always has considering the compression #s. When I pulled the plugs for the hot test, there was NO water in cylinders 1 or 3. There is no water in the oil either. Beside looking for an engine, I am guessing my next step is to pull the port side elbow and check the flapper (don't think I can get at it without removing the elbow and saving $35 for the gasket). Where else could the water come from? Dry Joint exhaust, no water in oil, no water in cylinders after running on hose. I will let it sit a while longer and check cylinders 1 and 3 gain. A friend at the marina said usually there is water in the oil when its a head gasket. Also I would think compression number on the cylinder with the a blown gasket would be way off. I would like to find the water intrusion and fix it so I can nurse the tired engine along for another couple weeks as boating season here in NJ will be over in early September, then I can come up with a game plan over the off season. As always any advice is greatly appreciated. Have a great Sunday.

 

[Rick Stephens]

I haven't dry joint, but seems that gasket is in the ten or twelve dollar range, not thirty five. Shutters are fairly pricey though. Having overheated you can be pretty sure they are toasted.

 

[mr300z87]

Thanks for the response Rick, I am going to pull the elbows and check the sudders this week when time permits, but might pull the drive and see if there are shudder parts in the exhaust first. I switched to dry joint system to prevent water intrusion from failed manifolds which were of unknown age. Here is a link to the gasket I need http://www.ebay.com/itm/MERCRUISER-...4280&clkid=7379851556397092920&_qi=RTM2247625

and he is the cheapest around. I bought them from this seller last year when I did the upgrade. Will post my finding here. Maybe I can get the boat back in the water next weekend and run it as is for the rest of the season. I thought my boat was a little hot rod as it was, I can only imagine what it will be like with as good engine.

Mike

 

[mr300z87]

Well tonight after work I pulled the drive hoping to see some burnt up flappers in the exhaust. Unfortunately I found nothing. Next step will be to pull the exhaust elbow on Thursday when I am off from work. If I find the flapper intact where do I go from there?? As I stated above, the engine ran fine the other day on the hose and I left water in the block and manifolds for an hour or so with none leaking into cylinder 1 or 3. I am also planing to pull the valve covers to check valve lash for a possible cause of low compression. Over the next few week as time permits I will pick up and leak down tester to try and diagnose the compression issue further. a couple of additional things I wanted to mention is I have no oil consumption, blue smoke, fouling of the plugs, the engine runs great (when no water is in the cylinders), has plenty of power and revs all the way the 4600 rpm some where around 45 mph(GPS) at WOT. Have a great evening.

 

[Grub54891]

Try a different compression tester. Sometimes they don't work just right.

 

[mr300z87]

That is not a bad Idea, will give it a shot.

 

[mr300z87]

Today I ran out to the Merc dealer and pick up a $42 dry joint gasket but decided that I should run the engine and let it sit for a while to see if any water makes its way to the cylinders. I can return the gasket if I done use it. So I gave it a good long run on the hose and it ran normal at nice cool 140 degrees (idle) then I shut it off and let it sit for an hour and half. I then when out and pulled no 1 and no 3 plugs, what I found was a few drops of water on no 1 and no 3 was dry. So I do not think it is the flapper. They guy at the Merc dealer said definitely that this is caused by a pin hole corroded through on the manifold. I have a new set of wet joint manifolds in my possession from a friends boat, they have maybe 10 hours on them, my question is there any reason I can not run the wet joint on port side and dry joint on starboard for testing?

 

[harleyman1975]

No answer to that but did you open throttle to full when doing compression test? if not that will explain low numbers.

 

[mr300z87]

So things are not looking good, besides it being 97 degrees with 97 percent humidity, I swapped out the exhaust today, I saw no evidence of water in the dry joint manifold that I was running but I swapped it out anyway with a brand new Mercruiser wet joint manifold and elbow. As usual the engine ran fine on the hose, we ran it up to temp plus another 10 minutes, then it was shut off and let to sit for a couple of hours. When we returned I pulled no 1 plug and much to my dismay there was some water on the plug and weeping from the plug hole.

With close to an hour of run time on the hose there is still no water in the oil. Yesterday before closed it up for the day I drained the water off the block only and left the exhaust manifold full. I had small amount of water in no 1 this morning. I only drained the block from the drain plug and did not pull of the large hose from the water pump as I do when winterizing. Is there still water in the from of the intake by the thermostat housing? Could there be a pin hole in the intake? I would think it would get into the oil if there was. Where do I go from here? If it was not so hot out I would be tearing off the intake I think? Hope to here some advice.

Harleyman I did not have the throttle plated propped open and I was thinking the same thing but was too lazy to redo. At this point the compression is the least of my worries as the engine runs great, I just need to figure out where the water is coming from. Not looking good for the rest of my 2016 boating season. I may just shift gears and try and finish project Sea Ray for next season.

 

[Rick Stephens]

If your manifolds are not the source, and you use acetone to check them. Then the block is. You can block off the hoses going to the manifolds and pressurize the block at the line coming in from the outdrive. See where it leaks. Use a stethoscope.

 

[NHGuy]

I'll bet it's the head gasket failed from the initial hot event. And/or the head or block surface could have warped. So when you do open it be sure to straight edge check it with a feeler gauge. The spec is .0039" or flatter. Your machine shop can do this correctly, it's best left to him.

 

[thumpar]

I like Rick's idea about using pressurized air. I would also pressurize #1 and listen.

 

[bruceb58]

Time to do a cylinder leak down test.

 

[mr300z87]

Thanks for all the replies. I need to PU an leak down tester, maybe tomorrow. My biggest problem at the moment is the weather. The heat index in NJ today is supposed to be around 110. Its like walking in to a brick wall when I go outside and unfortunately there is no end in site. Tomorrow AM I am going make sure there is no water in No 1 or 3 and run engine up to temp, then drain block, exhaust manifolds and intake so no additional water get in, Ill them fog those 2 cylinders with something to prevent any corrosion. Then when I get a break in the weather I can go out and do some more trouble shooting. This is an almost 30 yr old block with 330 hrs on it run mostly in salt water, could the block or heads corrode through. I would think if it was in the block or head I would have water in the oil, and I would assume that a hour of run time on the hose would enough cause milk shake if there was water in there.

Also wanted to mention that I found no standing water in the exhaust manifold upon removal, I did see what looked like a little bit of moisture on the exhaust valve. There are no rust stains in the exhaust ports. All I can do is keep plugging away at this. The good thing is I am fully capable of doing this kind of work, and actually enjoy it. I even have the gantry I built for the Sea Ray engine install to do an engine R and R if needed.

 

[mr300z87]

I thought I posted the above response yesterday but I guess it did not go through. Water was left in both the Manifold and block since running the engine on friday, and I was expecting to find water but both 1 and 3 were dry. After that I went and bought a leak down tester from HF and my results on cylinder 1 show all is good and I hear no air escaping anywhere??


I did find this on the underside of the port side filler cap so there is/was water getting in somewhere


I did some deeper inspecting of the dry joint manifold and I found no evidence of water entering from the exhaust. I would have expected to see some staining, and it looks to be in very good condition with little to no corrosion. I do not have enough acetone at the moment to fill the water side of the manifold for a definitive test.

Where do I go from here? As I am at a total loss. No water in oil, and leakdown test passes. This is so frustrating because if I new what was broke I could fix it, but I feel like I am spining my wheels going no where