Water in 2 cylinders when de-winterizing, what to do now. block or head gasket issue?

[glocklt4]

2005 Merc 5.0 with only 155hrs. Tried to start the boat and engine seized after about a half crank. Found water in two cylinders after pulling all plugs. I'm a car guy and have rebuilt an engine before but still learning specifics with boats, so in my world it would be cylinders 5 & 6 since it's a GM block. In case that is different, they were 2nd from back on both sides of engine.

De-winterized like normal for the past 4 years since I got the boat. Winterization process was to change drive lube, engine oil and filter, fuel filter, fog engine, open all 5 blue plugs on engine block and drain water then put plugs back in and fill engine with -50F deg antifreeze via main coolant hoses. To De-winterize I just check fluids again (and in the future will pull plugs to check for water!), check hoses and start her up with water flowing through impeller. Have never had this problem before with any engine.

Last year in Dallas we were below freezing for about 3-4 days straight, down to 8-10F. No problems with boat last year at all. Same winterization and de-winterization process last year as this year. This year I don't think we were below freezing for more than 8 hours, lowest was upper 20's overnight once or twice. We really didn't have a winter at all... I REALLY don't think it's possible that the block is cracked from frezzing unless it was cracked all last season but still worked fine (only got about 15-20 hours on her due to being out of town a lot).

Water in cylinders was pretty orange and rusty. No water in oil. I have not pulled drain plugs on engine to see if there is oil in the anti-freeze (this could be difficult to identify too). With all plugs pulled, I ran the started for 20-30 seconds listening to the crank/rods for knocking and also the valvetrain for ticking. All sounds good and quiet, so hopefully no damage from trying to start a hydrolocked engine.

My possible options on the cause are:

1) cracked block (but affecting two cylinders on opposite sides??)
2) two head gaskets that leaked into only one cylinder each (maybe coincidence that the two affected are exactly opposite each other)
3) rotten/cracked exhaust riser that leaked antifreeze or undrained water back through exhaust into cylinders

Compression on all cylinders was 105-115psi with one compression stroke except #5 (2nd to back right), which was only 90. I can retest all cylinders with more than one compression stroke but not sure that will make a difference. The times that I did get more than one compression stroke the cylinders were over 140-150psi, including one of the ones that had water in it. So this tells me no valve damage from seize.

So... I am not sure what to do to figure out how the water got in these two cylinders. On a car I'd use a block tester to verify if exhaust gases are getting into the coolant, but that only works on a closed lop cooling system.

After reading here and other forums I am thinking the next step is a leak down test and listen for air escaping when listening down the oil filler tube. That MIGHT indicate head gasket(s) are gone. If no hissing there maybe that indicates possible issue with block.

The other big variable which I just don't understand since I haven't taken one apart yet is the exhaust riser. I have read that it's possible for this to rot and let water in the exhaust. If only cylinders 5 & 6 had their exhaust valve cracked open then this could make sense.. but not highly likely. I just simply don't know enough about how these work.

Also, with all plugs pulled I ran the starter for about 20-30 seconds and listened closely to the small block and the valve train for knocks and ticks. Seems like the seize due to water in the cylinders did not bend anything from my initial investigation. I'm open to any suggestions on other tests to be sure that seizure itself did not cause any problems.

Recommendations on how to figure out how water got in these two cylinders??

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Couple more things. I have never noticed the engine overheat. I replaced the outdrive impeller 11/09, so it has been less then 3 years. Water flow through exhaust when I winterized was good. There was a bit of steam which I have never liked (as a car guy), but since coolant flows out the same spot as the exhaust, and got engine can cause coolant to steam when it's cool out, I think that was ok. It is a possible indication of a blown head gasket though. It did NOT steam immediately when started, only when warm.

Also, the more I read the more I am suspected the exhaust risers. again, I do not know much about these, however I do know that they have not been replaced. 2005 boat/engine, so that means they are 7 years old. Previous owner said that they ran the boat in Houston harbor area in salt only a few times and flushed immediately after. He worked for NASA, so I trust that he knew what he was doing with this flush. I have never run the boat in salt and the boat is kept out of the water except when we take it out.

Is it easy to remove the risers to check for rust and see if this was the cause of my leak?

Does the fact that water was in two specific cylinders possible indicate that the anti-freeze I put into the hoses of the engine while winterizing mean that it went through the risers and back through the exhaust ports?

I have never had any problems with this engine at all except sometimes it takes a while to start, which I attribute to being a carbed engine (all of my cars have been FI and start much quicker than the boat ever has).



BTW, others on the vette forum i've been apart of for over 10 years are saying that cranking the engine over to check valve train and things as well as compression on cylinders was a bad idea with rust in them and that probably means that i've scored the cylinder walls causing a rebuild now.... awesome.

 

[SCORPIO]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

First off, I think I'd spray a lot of WD-40 or other water displacer into those cylinders to lube them up and drive off the water, will also help prevent further rust. Its possible you scored a cyl but only a borescope or a teardown will tell you. I think you need to find the cause before you try a cure. I'm concerned that there was WATER in you cylinders. If a riser failed and you had all the water out of the engine then the only thing that should have been able to leak into the cyls would have been anti freeze. Since you say it was in fact water, then I don't think you got her drained out well enough before filling with AF. I always open my drains, and poke a stiff wire into the opeings to see if there is any scale plugging the hole preventing complete draining. I then pull any hose that could have water in it, especially the big hose from the circulator pump to the thermostat, its usually full of water. Also pull the inlet hose after the oil cooler as well as the hoses off the bottoms of my exhaust manifolds.
OK, you know you had water in there somewhere, no the HOW it got into the cylinders. A bad riser is a possibility but the fact that you had water on both banks is a bit odd. I don't really know the valve timing on GM engines that well so I can't say that only those cylinders had exhaust valves open. Could also have to do with the agle the boat was stored as to where the water would accumulate. Is your boat carbed or FI? Could rain water have leaked past a hatch and gotten into the intake and from there into the engine via open intake valves? I always cover my carbs with plastic bags after fogging to help prevent water intrusion.
I'd pull you risers and check them, in fact at 7 years old I think I'd replace them as they can and do fail with age. I have four seasons on mine and am planning on changing mine after this season. I'm in salt water though, but I do flush, still don't know how effective flushing is for risers.
After you get the cyls lubed and dry, a compression check and an oil change are going to be in order. I like the leakdown test idea too. I somehow doubt you have a cracked block. Usually a water passage will crack the external block and you would be able to see that. Its possible that you have a dual head gasket failure but on the same cyl on both banks is really unlikely unless its some kind of pattern failure with that engine design.

If it were me, and I could, I would scope the bores, do a compression check/leakdown, pull the risers and inspect, and lastly, if nothing jumped out at me, pull the intake and heads. Start from the simple and work to the complex and let us know what you find. Pics are a great help as well in helping us help you.
Good luck
PS forgive the rambling stream of my post, haven't had my coffee yet.

 

[dlvwill]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

I would start with taking the risers off and see what you have. Loosen clamps and the 4 vertical bolts holding it to the manifold and see what you have. You need to get oil , WD40, something into those wet cylinders while you are diagnosing to stop the rust.

 

[BonBini]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Check to see if you’ve got some exhaust drain blockage back at the transom.

1).. the eng hydro locked during cranking. I seriously dought any damage was done.

2).. #5/6 cylinders had water in them not the antifreeze you poured in. So the contamination to the two cylinders in question did not come from the engines water jackets or cylinder heads. most likely came from the exhaust that you are eluding to. the water did slowly leak past rings and contaminate the engine oil. you rolled the engine over and mixed it all up so an oil change is now due.

3).. compression test results are inconsistent. when performing compression test, turn over engine about ten pumps. if you got 140/150 then don't worry about a leak down test. that’s only for pinpointing problem if you got a low hole.

4).. you fogged the engine for cylinder protection. when the water got in, it most likely floated the oil film protection off the cylinder. but only in the area the piston was parked for the winter.

Based on the above: Yes there is some cylinder damage. Most likely low in the hole and not up top in the critical compression area. Might use a little oil on those two holes. I would squirt some oil in all the cylinders and roll it over a few times. Put the plugs back in and fire it up and warm it up ( don't turn garden hose on full blast at first, get it running on some water then open it up). If it seems to run good. Then pull the manifolds for inspection and reseal. Also pull that drive for service and water pump replacement.

 

[testlab]

I'd start with the risers, then move onto exhaust manifolds. Then do leak down test or similar. I am guessing it's a joint failure (do 2005 5.0s have dry joints from new??). Seven years is a good run and perhaps your AF wasn't sitting in the risers and the lack of corrosion inhibitor has resulted in the riser or joint failing.

Diesel is great for drowned or wet bores. A bit messy but better than WD40 or CRC in my opinion. Squirt directly into plug holes while cranking several rotations ( use partial rotations) and then try and park engine with those pistons at bottom of stroke.

Edited to add after reading above... Isn't there a warning about running the hose too long without the engine running? Could the rusty water have been back flow? The rust coming from 7 year old risers and only entering these cylinders during de-winterizing?

 

[BonBini]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

I might be a little cautious about using any penetrating oils or rust breakers in the cylinders. Some of these oils actually do something to the metal to make drilling holes easier and there chemical properties attack surfaces. I'm concerned what would happen to the piston ring plating! Diesel fuel used to be pretty good for stuff like this, but now with the sulfur gone... not sure about that either. Just Sayin

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Thank you so much all for the prompt responses.

More info as requested:

-It is carbed.
-Do not think rain water got in. Sun deck is on top of engine and carb has flame artestor on it. We only took the sun deck off for 3 weeks to have it repaired and boat cover and flame arrestor still on. In hindsight I should have covered the engine with a tarp to be sure.
I have sprayed fogging oil in all cylinders, with about 5-6 seconds worth in the ones that had water (directions say 3 sec normally).

Couple quick things to add.

-The oil is now all drained and NO water.
-I used Splash brand -50F pink RV/Marine antifreeze. The water that was in the cylinders was pretty rusty so I don't know if it's possible that it was actually the AF that had turned from pink to orange. Not sure if it is possible for that AF to really rust like that. If NOT, then you all have a very good point about WATER in the cylinder vs AF, which I hadn't thought of. That would most definitely point out problem draining water from the plugs on the manifolds/risers.

After your recommendations I have taken the risers off. When doing this I unscrewed the blue plugs on each manifold and a good amount of rusty WATER (identical color water that came out of cylinders) came out of the right one, and not much out of the left (and not as rusty). I am now pretty confident that there was not AF in them. I pulled the other plugs on the lower block and the one on the water pump as well and nice pink AF came out. Did not look like any oil was in AF. So it does indeed seem like somehow I did not get water out of the risers/manifolds. Maybe I didn't undo them (which i would be surprised) or they didn't drain all the way as some have suggested. I thought that I got in the habit of sticking something up the drain hole to be sure it was drained because I have read about that, but it has been 6mo now and I may have forgotten to.

At this point I think the block is fine for AF or oil would have been mixed with the other probably. Also, there was plenty of AF in the block to prevent cracking.

Here you can see down the left manifold and water is sitting in there on cylinder # 5 which is the first one that I found water in. Seems like a riser/manifold issue if water is sitting there! Only way that I could see water getting there if it was not riser issue is if somehow cranking the engine pushed water out the exhaust valve and into the manifold, but i would have expected that to be at a high pressure and spray everywhere not just in that little area.

The other side doesn't look that bad, but still shows signs of rust and on the correct cylinder #5 that had some water come out (don't know why i have GOLD in my engine from the picture, but maybe I should take it apart to discover if someone poured gold down my engine... i'd be ok with that ):

Now, someone mentioned angle of boat... I think that COULD have to do with why cylinders #5/6 were affected. For winter i made sure that it was tilting a bit (not flat) in case of heavy rain. We park it outside by covered with boat cover. Angled towards the back due to tilt of boat on trailer and only two cylinders that are easily affected by water going straight down from the riser... the back cylinder directly under risers does make a bit of sense.

Additional pictures to assist.... (is it normal to see so much rust in the water passages of the manifolds and risers??)

Left bank:

Right bank:

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

One more question while I'm at it. Is it possible that last year I did not winterize the risers/manifolds well enough when we actually did have a good hard freeze cause them to crack, and that I was able to run the boat fine for about 15-20 hours over a 6mo period with it this way? Or with this kind of obvious leak, would I have noticed serious engine issues even prior to winterization this year?

Are there any classic signs of riser leaks besides flooded cylinders?

 

[ardeprint]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

If you have water in your exhaust pocket then it is safe to assume it came from a riser joint failure.

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Ok, good (kinda). So besides trying to figure out what other damage was done (if any), do I need to replace just the risers or do both risers and manifolds?

 

[fwebster]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

You have pretty well narrowed this down, but here are some observations:

Clue: water in the middle 4 cylinders- almost certainly points to water entering thru the exhaust system since moisture will end up in the cylinders right under the manifold exit to the riser.

The reason you have low compression on on cylinder is because the valve was open and there is some rust on the valve face. It may clear after running a few hours, but if the head or valve is pitted, count on a valve job in the future.


I suspect there is a crack in the interior water jacket on the riser on the side where you found the water. I would have that one cleaned and magnafluxed before reinstalling it or you are going to find water in the engine again ....soon.

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

You have pretty well narrowed this down, but here are some observations:

Clue: water in the middle 4 cylinders- almost certainly points to water entering thru the exhaust system since moisture will end up in the cylinders right under the manifold exit to the riser.

The reason you have low compression on on cylinder is because the valve was open and there is some rust on the valve face. It may clear after running a few hours, but if the head or valve is pitted, count on a valve job in the future.


I suspect there is a crack in the interior water jacket on the riser on the side where you found the water. I would have that one cleaned and magnafluxed before reinstalling it or you are going to find water in the engine again ....soon.

Good to know that center two cylinders points to risers easily.

I have no problem replacing the risers rather than testing/fixing since they are 7 years old now.

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

More pictures now that the risers are apart. Rust pretty much all over the place. Any of this look normal? Also, where is the best place to buy replacements, and are there core charges on these kinds of things like auto parts?

left:

Right:

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

UGGGH!!!!!!!!!!!!!!!!!!!!!! I was trying to put WD40 into the cylinder and the straw just flew off the spray nozzle and INTO THE CYLINDER!!! Just my luck that it happens to be at the bottom of the stroke and was able to fit inside... AWESOME.

So now, suggestions on how to get that out without pulling the head?? Grrrr........ The exhaust manifold is making it difficult to see and is why i wasn't able to hold the straw as I was spraying. Perhaps I should just go ahead and take it off so that I can get better access to see to try and fish that out now with something.

 

[ardeprint]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Try using a vaccum with a flexible small diameter hose. You may have to make one.

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Ok, thanks. Also have a buddy coming over that said he's gotten a spray tube in a cylinder before and used a hanger wrapped in some thin doublesided tape to stick to it and pull it out.

 

[glocklt4]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

Red spray tube is out of the cylinder! Thanks to my buddy who is great with hooked hangers (covered with some double sided tape to help be sticky and avoid scratching cylinder walls). Also, the cylinder head looks nice and clean. When we had the vacuum hooked up to a tube and were fishing around in there, some water came out and it was clear/yellowish. So I think that the cylinder is probably alright. I'm still going to order a scope to see if I can look in and see any corrosion.

 

[SCORPIO]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

For future reference when using one of those red straw tubes on a spray can in a cylinder, put a piece of tape on the tube. Use about an inch and a half of tape and center the straw in the tape and fold it over on itself. This 'wing' shape will prevent the tube from going into the cylinder if it should come off during use.

 

[dicor]

Re: Water in 2 cylinders when de-winterizing, what to do now. block or head gasket is

This may help retrieving the tube