Blown Head Gaskets? Somthing else?

We have a 2011 Moomba Mobius XLV with ~120 hours on it. The boat has been running perfect until yesterday. I don't know if this is coincidence or not, but when my son was emptying one of the ballast bags, the fitting came loose so instead of pumping the water out of the boat, the water went into the hull. Not realizing this, he drove the boat home (not far) and as he got close to the lift at our place, the motor starting running rough.

So tonight I pulled all the plugs, and on each side, the front two (nearest the transom) were perfect. However, the back two were wet, and not with fuel. I dis-connected the coil and turned the motor over and particularly out of the third cylender on EACH side, a bunch of what appears to be water pumped out. The last cylinder was not as bad.

We dried off the plugs, fired the motor up, and everything seemed to run pretty well. However, the check engine light was on, and as we got back to the lift, the motor started running rough again. Pulled the plugs, same thing....

My initial thought was that we either cracked a block, cylinder head, or blew a head gasket. However, it just seemed strange that it would affect the SAME cylinder on EACH side of the motor?

Next step is to take it into the dealer and prep the checkbook for a very big bill. However, I thought I'd reach out and see if anyone has heard of anything similar with Indmar motors? Bad timing, we're in the NW and we're going to miss the best month of the year!

Thanks in advance for any insight.

Scott

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Originally Posted by scottg

We have a 2011 Moomba Mobius XLV with ~120 hours on it. The boat has been running perfect until yesterday. I don't know if this is coincidence or not, but when my son was emptying one of the ballast bags, the fitting came loose so instead of pumping the water out of the boat, the water went into the hull. Not realizing this, he drove the boat home (not far) and as he got close to the lift at our place, the motor starting running rough.

So tonight I pulled all the plugs, and on each side, the front two (nearest the transom) were perfect. However, the back two were wet, and not with fuel. I dis-connected the coil and turned the motor over and particularly out of the third cylender on EACH side, a bunch of what appears to be water pumped out. The last cylinder was not as bad.

We dried off the plugs, fired the motor up, and everything seemed to run pretty well. However, the check engine light was on, and as we got back to the lift, the motor started running rough again. Pulled the plugs, same thing....

My initial thought was that we either cracked a block, cylinder head, or blew a head gasket. However, it just seemed strange that it would affect the SAME cylinder on EACH side of the motor?

Next step is to take it into the dealer and prep the checkbook for a very big bill. However, I thought I'd reach out and see if anyone has heard of anything similar with Indmar motors? Bad timing, we're in the NW and we're going to miss the best month of the year!

Thanks in advance for any insight.

Scott

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Sounds a lot like the water is coming in through the exhaust.
Are you missing your flappers?

Didn't even think of that, will have to check that! Thanks for the idea...

Well, that wasn't it, both are still there. Besides, if any water did get through, it has a pretty long climb to get up into the motor. The water that did get into the engine compartment could not have gotten much more than above the oil pan. I checked the dipstick, and it does appear to have water in oil pan. So water is definitely getting into the motor, just not sure if it's a block, the heads, a head gasket, or something else?

Is there water in the oil?

Brian

Yes, there is also water in the oil pan. So water is getting into the motor, just not sure how or where from. Worried about the big things like cracked blocks, cylinder heads, or blown gaskets, but HOPING for something simpler!

When the boat is running rough and the engine light is on, what are the reading for temp and oil press? It is possible that you have a problem with your exhaust risers, allowing water back down through the exhaust. However, it sounds more engine related. Since you can pull the plugs, get a compression tester and check the compression on the cylinders. Autozone type stores rent them and harbor freight sells one cheap.

What seems to strange, at least to me, is that I have water in the oil pan and the rear (away from the transom) two cylinders on EACH side of the motor, but the front two cylinders look great (the plugs are dry and the color is perfect). They worst cylinder on each side is third cylinder away from the transom. It just doesn't make sense that same two cylinders on each side would be good and the same two cylinders on each side would be bad.

When we ran the boat last night, the water temp never seemed to climb above the lowest level on the guage, although we didn't run it long once we saw the "check engine" light on. Oil pressure is above 14 psi, so I don't think that is the issue.

I'm not familiar with the exhaust risers, but would they BOTH be bad, and would water typically creep into one or two cylinders only?

Appreciate your time and thoughts on this!

The risers are essentially a set of headers inside of a big cooling jacket. If the header pipes crack, water will drip down in the exhaust valve when it opens.

No, it wouldn't make sense that both would crack in the same place at the same time.

They also last about 10 years in salt water, so it really wouldn't make sense in your case.

Head gasket doesn't fit the bill either. Inboards run 20 degrees cooler than car engines and the cooling system isn't pressurized. Head gaskets won't fail unless you overhead and deform the head, or unless you have a ton of hours.

It sounds like exhaust, or intake. Did the spilled bag spill on the air filter? Have you recently gone from forward to a hard reverse? I know you said the flappers are way below the exhaust manifolds, but when you are in the water, the level in the exhaust is the same as water level. With ballast, its not a very big cilmb for the water.

Have you had the intake off recently?

I do not believe it is a head gasket.

I don't think the spilled water got much above the oil pan, given that the floor of the boat is even with the lower portion of the block. So I would think any excess water would just go up forward in the hull, right? As for a hard forward / reverse, I can ask my son (he was driving - I wasn't there), but before he emptied the bag, he was just surfing (10 - 11 mph), so I'm not sure that would really be considered a hard forward / reverse action? If the water DID come through the flappers / exhaust, would it be normal to have the water fill only two cylinders on each side? Would something like that trigger the "check engine" light, or do you think that is simply a by-product of it (and if so, what might THAT be)?

I have not had the intake off the boat. Up until Tuesday, everything was working perfect.

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Originally Posted by scottg

I don't think the spilled water got much above the oil pan, given that the floor of the boat is even with the lower portion of the block. So I would think any excess water would just go up forward in the hull, right? As for a hard forward / reverse, I can ask my son (he was driving - I wasn't there), but before he emptied the bag, he was just surfing (10 - 11 mph), so I'm not sure that would really be considered a hard forward / reverse action? If the water DID come through the flappers / exhaust, would it be normal to have the water fill only two cylinders on each side? Would something like that trigger the "check engine" light, or do you think that is simply a by-product of it (and if so, what might THAT be)?

I have not had the intake off the boat. Up until Tuesday, everything was working perfect.

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Water in the exhaust would likely trigger the O2 sensor malfunction code. This is a trigger for the check engine light.

Whichever exhaust pipes are the easiest for water to flow into would have water in the associated cylinders. I have never seen the internals of an Indmar manifold, but I would guess they are symmetrical.

If the two wet cylinders have the easiest flow path, it would make sense that only those two would be wet, and on both sides.

In the scenario I am using, the water would have to be coming in each exhaust port, at the same time. I cannot imagine any scenario that is more likely.

Sorry to hear about this man, I would be more looking at your insurance company then your check book, this bill will run you between 1k for simple to 6K for engine replacement / rebuild.

There is something missing to this story from the way i read it.

Details
Out surfing, No issues, no over heat, no problems
Draining Ballast and it drains into the bilge
Bilge pump works?
Still water only fills to 1/2 the depth of the oil pan

I was in a boat last year in Oct that we had water almost covering the crankshaft pully, and all we had was belt whistle and lots of splashing water.

Now engine runs ruff, and we have water in the 3 and 6 cylinders.

Oil pressure is LOW at 14psi, it should be 20 min with operating 40-60

Water in the engine means, blown head gasket, leaking exhaust manifolds, water through your intake.
Blown head gaskets are the most likely item yet its really rare you would blow both sides and leak in 3 and 6 cylinders only.

Leaking exhaust manifolds would be a good choice, depending on the engine firing order it could shut down with an exhaust valve open allowing water inside the engine. Would it be both 3,6 holes? IDK off hand. There is absolutely NO way water can go back through the exhaust manifolds into the engine when its running, you have 3 other cylinders pushing exhaust out the entire time.

Water in the intake, would be the least likely because for 1 you would have had to take a HUGE amount in, which would typically stall the engine, and it would be in all the cylinders.

Like i said something is missing from this story.

You best best is to do the compression test on each cylinder, good readings mean water is coming in elsewhere, bad reading on any cylinder means head gasket failed, or rings are bad.

Check engine light is default, it could be low oil pressure, emissions readings, fouled plugs, exhaust is rich with fuel, engine is knocking due to dead cylinders. To many things to worry about, the worry is that you have water in the engine and oil.

You're right on the oil pressure, I think that may have been a typo, although I don't remember what the guage WAS reading. I'm really stumped on this, it just seems so wierd to have problems in the same two cylinders on each side at the same time, with no signs of problems ahead of it. Blown head gaskets / cracked cylinder heads don't seem reasonable to me, even a cracked block, because of the symmetry (same cylinders, similar amounts of water, etc).

Nate's thoughts on the water coming in from the exhaust seems like it could be more likely, as it would be even on both sides, and we did appear to have similar amounts of water in the third cylinder and fourth cylinder on each side. Plus, there seemed to be MORE water in the third cylinder than in the fourth. Of course, that may be "hope" shining through, as that seems like it should cost far less than heads / blocks!

We have to take this into the dealer, it's beyond my skill set, but the more I can do to try to eliminate it will hopefully save the dealer some time and hopefully help me avoid getting screwed over by them.

Really appreciate you guys taking the time to provides some thoughts and insight. I haven't had issues with our boats, so I'm trying to figure this out from a "car guy" perspective.

Ask me how I know: If your impeller or water pump fails, you can warp a head, blow a head gasket, or crack a block.

Do you have the engine with CATs?

Since your boat is an 11, it is still under warranty from Indmar. Call the dealer.

I'm guessing you've been there then? I wasn't in the boat, and my son didn't think to look at the temp gauge, so we're not sure if the boat was overheating. The local repair shop thinks the motor overheated and we blew the head gaskets. That WAS one of my initial guesses, but seems a little weird that both blew, and in the exact same spot. I did have my son check the impeller and he "thought" it seemed to work fine, but when we tested the motor briefly last night, we could never get the water temp guage to move, so maybe it's not picking up any water? Sure wish these things came with some sort of "alarm" when the temp got to a certain level, but too late for that!

Not sure if this will be under warranty, we bought the boat used last year. Not sure whether the boat has CAT's or not.

There has to be a transfer of warranty paperwork and a 200 fee to indmar to transfer the motor warrantee. I believe.

Details on warranty.

http://www.moomba.com/warranty/

This is a wild ass guess at best but after a quick look on google the intake on that thing would be my first suspect.

since it is always the same cylinders that makes it tough to be the exhaust.
Water in oil can be explained by the water leaking by the rings. Or one of the coolant passages in the intake cracked across to a shared intake runner.

Again this is a guess based on many years of automotive experience and looking at pictures of what could be an engine like yours.

The easiest thing to do, if you have the tools, and the skills is to run a compression test. All the cylinders should be very close, any more than a 10% variance should be looked at. But I doubt that if you have a blown head gasket there will only be a 10% difference. If after this and you find a variance you could run a leak down test. Which is more difficult and requires another tool. The leak down test will help you figure out what is leaking. Either way water in the oil is not good and probably requires at best removal of intake first, then heads if nothing found well then keep going. If you are so inclined and just want to try, you could change the oil and see if water gets in the new oil. If you try this say a prayer first, it may help. I also find it hard to believe that there were not alarms going off if the motor overheated. A good rule of thumb for oil pressure is 10lbs/ 1,000 rpm. So i.e. 4,000 rpm should have 40lbs to be safe. So if you did indeed have 14lbs oil pressure you have some serious issues. But I would be willing to bet you mis read the gauge or faulty gauge, again you would have alarms going off. Clear as mud??

Brian

Thanks to everyone for ideas, at this point we're just going to take it to the shop and pray that they don't screw us over too bad. I agree that this doesn't look like blown head gaskets or cracked block / heads, the symmetry of the problem just doesn't seem to support that thesis.

There were NO alarms going off at all, so I don't think it overheated or had low oil pressure, but clearly something IS wrong! This has been very helpful though, as I can have some ideas / perspective when I'm talking to the shop(s) to see if they have some ideas, or if they are just guessing and are going to throw time / parts at it until they figure it out.

Many thanks to everyone for taking the time to provide some thoughts and ideas here, really appreciate it!

What ever happened on this? I'm late to the party, but am curious how it turned out.

I had a small water leak from the port exhaust manifold a few years back, near the rear two cylinders. I pulled the riser and exhaust manifold to find that the Permatex Indmar uses for the seal between the engine and the manifold had failed or wasn't probably applied - looks like they didn't use enough.
Coupled with that I think that my riser gasket was installed at an angle, allowing a small amount of water to leak out of the water jacket portion of the riser-to-manifold joint, and seep down to the manifold-to-engine joint.

So, I removed the permatex from the manifold and engine, and installed a paper gasket - works great. I also installed a new riser gasket. No issues since.

My only thought, in addition to what has already been said, was maybe your riser gaskets failed on both sides. It seems strange to lose both at the same time, but, anything is possible. Contrary to what Mike said, I know that you can get leaks from the water jacket in your exhaust down to the engine - luckily it wasn't a large amount of water in my case.