Cracked block or two blown head gaskets?

[MFK27]

My husband and I recently bought a 2006 Malibu Wakesetter VLX with an Indmar 340 engine with 700 hours. Before buying, we test drove the boat for over an hour, checked engine oil before and after running, inspected the hull, have previous owner’s maintenance records, etc. Based on the following info, would probably hire someone to inspect the next boat we buy....life lessons

After using the boat for a little under 7 hours for wakeboarding and wakesurfing, we noticed the oil was milky. While still in the water, we siphoned out the oil and found 6 quarts of water. We then changed the oil and ran the boat again for 10 minutes back to the boat launch. Once we got it out of the water, we drained the oil again and found more milkshake/water. Based on our research we thought it might have been the exhaust manifolds leaking so we removed and found water in all cylinders (some more than others). We did a very basic test to see if the exhaust manifolds were cracked/leaking and the results indicate they are not. The extent of our knowledge about boat engines is limited, so we stopped there. 

I should mention - the engine did not overheat but the engine was having trouble turning over once we hit the 7 hour mark (prior to emptying the water out of the engine). 

Based on the symptoms I described, does this sound like two blown head gaskets or an internal crack to the block? The boat was winterized by a marina and we have the maintenance records to prove it. The marina who winterized is telling us it’s two blown head gaskets (compression test results - zero pounds of compression on starboard middle cylinders and 40 pounds in port middle side. Did not provide results on the other cylinders) another marina we went to for a second opinion does not believe that’s true and they are very confident it’s a crack in the block but only did a visual inspection. 

With that background info, how likely is it to blow two head gaskets simultaneously without an engine overheating/just generally? What is likely to cause that much water to enter the engine? 

Really appreciate any perspective you can provide! Thank you.

Edited May 31, 2020 by MFK27
Misspelling

[ahopkins22LSV]

I am sorry this is your first post, but welcome.

Did you test drive the boat before winterization? I don't see how this couldn't be caused by an improper winterization with the test drive you described. Right now I agree with the second shop that this sounds like a cracked block.

[minnmarker]

Those compression numbers are telling.   What prompted you to check the oil?  Some perfomance anomaly?

Head gaskets, absent other issues, will be a cheaper fix than a cracked block.

[oldjeep]

Sounds like a couple cracks in the block in the cylinder walls.

[MFK27]

Thank you everyone for your quick responses! 
 

@ahopkinsVTX - thank you, appreciate that. We test drove the boat after winterization. The previous owners picked up the boat from the marina’s storage unit and our test drive was the first time they put it in the water during 2020. We checked the dates on their winterization form and they had it winterized before the first frost and picked it up after the last frost. 
 

@minnmarker - We were prompted to check the oil when the check engine light went on and we started powering down. 
 

@oldjeep we thought so too. Hoping it’s not but also wonder if the marina will work with us since it’s a winterization issue and we have record of everything they did. 

Edited May 31, 2020 by MFK27

[Woodski]

It potentially sounds like both - head gasket on starboard side and maybe a block crack on port side.  The Small Block GM engine has the exhaust valves adjacent to each other in the middle cylinders and the cylinders are siamesed so that tends to be a hot spot.  Result if engine gets hot is head gasket deterioration and ultimate failure between those 2 cylinders.  You will hear the result as a popping sound through the intake system.  A failed head gasket is not a winterization issue, it is a heat related issue.  To answer your head gasket question without an overheat very unlikely to blow 2 head gaskets simultaneously.  The port side low compression coupled with water in the oil points toward a block crack which could be a winterization issue although the most common crack is between the core plugs.  Another potential could be a holed piston if coupled with another path, an intake manifold gasket, the water got in to the combustion chamber. 

A few more observations -

• you note 6 quarts of water, can you elaborate on whether that is an additional 6 quarts of water in the oil pan or you drained a total of 6 quarts of oil / water mix out of the pan. 
• indicating you have all cylinders water filled, that points to some other ways the water got in the combustion chamber.  If all are full, there is a potential the water came via the exhaust side, you indicate ballasted type of activities, did you perform these with a lot of ballast?  Was the boat shut off hot in the water with a lot of extra weight thus having the waterline high on the boat?  That would allow an easier opportunity for the water to draw back in to the dry section of the exhaust manifolds.
• you note during the test phase the oil was checked before and after the runs and can one make the assumption that all was good and no milky oil was present?  How does that run compare to the 10 minute run where milky oil was discovered?
• trouble turning the engine over was probably due to water in the cylinders and the engine being on the cusp of hydrolock, the extra water in the combustion chamber would in effect raise the compression ratio thus taxing the starter.

I would suggest a leak down test to help further the diagnosis, including using a stethoscope to pinpoint where the leak is happening.  You will want someone that understands how to do this.  Also, prior to starting the engine any more, remove the spark plugs to turn the engine over to evacuate all the water and don't fire it if the oil is milky.

[MFK27]

@Woodski - Thank you for all the information. I hadn’t considered that it could be a head gasket and cracked block.

to answer your questions...

1. It was an additional 6 quarts of water. 
2. We did have ballast filled in the back tank but did not shut it off hot. We thought potentially water was getting through this way also but during the 10 min drive from our house to the boat launch, the oil became completely milky again and more water draining (zero ballast) 

3. yes before test drive we checked the oil and it looked great. Then we drove for an hour at different speeds, with and without ballast etc, and tested the oil after and still looked great. We then got the boat home and had it in the water for 7 hours before the oil became milky (We checked the oil after every trip). We brought the boat back to the boat lift at our house and siphoned the oil and water out / changed the oil. Then drove it back to the boat launch (10 min) and the fresh oil had turned completely milky again. 
 

Thanks for the advice on the leak down test. We will talk to the marina about this. 

Edited June 1, 2020 by MFK27
Typo

[oldjeep]

How much additional volume did you get after the 2nd time the oil went milky?   It does take a few oil changes to stop that from happening if you have not pulled the pan and valve covers off and really cleaned all the mayonnaise out of the motor after you get water into it.  Especially if you were siphoning and not draining from the pan drain.

Edited June 1, 2020 by oldjeep

[MFK27]

@oldjeep - good point. There was another 1-2 quarts of water in the oil the second time (not in addition to the oil, from what I remember). So we changed the oil again (third time) and then trailered it to the marina. so three oil changes in total and we didn’t put it back in the water after the third. However, the marina ran it again via fake a lake and the oil turned milky a third time. 

Edited June 1, 2020 by MFK27

[oldjeep]

18 minutes ago, MFK27 said:

@oldjeep - good point. There was another 1-2 quarts of water in the oil the second time (not in addition to the oil, from what I remember). So we changed the oil again (third time) and then trailered it to the marina. so three oil changes in total and we didn’t put it back in the water after the third. However, the marina ran it again via fake a lake and the oil turned milky a third time. 

OK, so with that volume it is definitely still getting new water into the engine

[MFK27]

Yes unfortunately :/ 

Edited June 1, 2020 by MFK27

[MFK27]

15 minutes ago, oldjeep said:

OK, so with that volume it is definitely still getting new water into the engine

Yes unfortunately :/ 

just figured out how to do replies correctly ha! 

[BoatFlyRide]

 

On 5/31/2020 at 7:59 AM, MFK27 said:

My husband and I recently bought a 2006 Malibu Wakesetter VLX with an Indmar 340 engine with 700 hours. Before buying, we test drove the boat for over an hour, checked engine oil before and after running, inspected the hull, have previous owner’s maintenance records, etc. Based on the following info, would probably hire someone to inspect the next boat we buy....life lessons

After using the boat for a little under 7 hours for wakeboarding and wakesurfing, we noticed the oil was milky. While still in the water, we siphoned out the oil and found 6 quarts of water. We then changed the oil and ran the boat again for 10 minutes back to the boat launch. Once we got it out of the water, we drained the oil again and found more milkshake/water. Based on our research we thought it might have been the exhaust manifolds leaking so we removed and found water in all cylinders (some more than others). We did a very basic test to see if the exhaust manifolds were cracked/leaking and the results indicate they are not. The extent of our knowledge about boat engines is limited, so we stopped there. 

I should mention - the engine did not overheat but the engine was having trouble turning over once we hit the 7 hour mark (prior to emptying the water out of the engine). 

Based on the symptoms I described, does this sound like two blown head gaskets or an internal crack to the block? The boat was winterized by a marina and we have the maintenance records to prove it. The marina who winterized is telling us it’s two blown head gaskets (compression test results - zero pounds of compression on starboard middle cylinders and 40 pounds in port middle side. Did not provide results on the other cylinders) another marina we went to for a second opinion does not believe that’s true and they are very confident it’s a crack in the block but only did a visual inspection. 

With that background info, how likely is it to blow two head gaskets simultaneously without an engine overheating/just generally? What is likely to cause that much water to enter the engine? 

Really appreciate any perspective you can provide! Thank you.

The symptoms you describe sound remarkably similar to what I experienced on my old Response LX. My guess is that the boat was over-heated at some prior to your ownership and you bought the boat with head gaskets that were on the verge of failing. 7 hours of high-load use later (I am assuming here based on your comments on ballast) they decided to let go.

My old Response would start and run well even with almost zero compression on the middle cylinders on one bank and mid 50's on the other. The only symptom was a high rpm misfire.

Edited June 1, 2020 by BoatFlyRide

[MFK27]

44 minutes ago, BoatFlyRide said:

 

The symptoms you describe sound remarkably similar to what I experienced on my old Response LX. My guess is that the boat was over-heated at some prior to your ownership and you bought the boat with head gaskets that were on the verge of failing. 7 hours of high-load use later (I am assuming here based on your comments on ballast) they decided to let go.

My old Response would start and run well even with almost zero compression on the middle cylinders on one bank and mid 50's on the other. The only symptom was a high rpm misfire.

Sorry to hear you had this issue too... it sounds like then, that you also had lots of water in the engine? Did you end up replacing the head gaskets or doing more? 

The engine definitely has high hours, so it’s possible our ownership timing is just really bad (sigh) or the previous owners knew what was happening and sold it to us anyway without disclosing. 

[UWSkier]

700 hours isn't really that high honestly.  These engines are made of iron and aren't high-strung race motors.  It takes something fairly catastrophic to break one.  Very strange indeed to have water in both banks.

[boardjnky4]

6 quarts of oil sounds like a lot more than what a head gasket would do. Especially since you ran it for a limited time and found ANOTHER 2 quarts.

I have heard of freak instances of winterizing a boat where the heads end up cracked. It was a dealer winterized boat, and they don't know how it happened.

Is there a lot of white smoke if you run it on a fake a lake?

Sadly, many time it takes a dissassembly to find the root of the issue. If it were me, I'd pull the heads. Inspect the heads, inspect the water passages and all cylinder walls while heads are off. I'm sure you'll find your culprit before long.

Edited June 1, 2020 by boardjnky4

[BoatFlyRide]

21 minutes ago, MFK27 said:

Sorry to hear you had this issue too... it sounds like then, that you also had lots of water in the engine? Did you end up replacing the head gaskets or doing more? 

The engine definitely has high hours, so it’s possible our ownership timing is just really bad (sigh) or the previous owners knew what was happening and sold it to us anyway without disclosing. 

I did both sides myself. It was pretty straightforward and ran about $1,200 bucks including machining and parts.

Dealership quote was over $5,000.

 

I agree with others that more diagnosis is needed before pointing to solely at the head gaskets.

It’s just odd the problem didn’t surface during your water-test otherwise.

[MFK27]

15 minutes ago, UWSkier said:

700 hours isn't really that high honestly.  These engines are made of iron and aren't high-strung race motors.  It takes something fairly catastrophic to break one.  Very strange indeed to have water in both banks.

Okay, that’s good to know about the hours. Concerning about a catastrophic event haha.. but I think you’re right. This situation is so strange... However have to keep in mind the marina that winterized the boat believes it’s the head gaskets (a non winterization issue). But hey, after this is all over I might be reporting back on this page that the marina was right. Trust but verify! 

[MFK27]

16 minutes ago, BoatFlyRide said:

I did both sides myself. It was pretty straightforward and ran about $1,200 bucks including machining and parts.

Dealership quote was over $5,000.

 

I agree with others that more diagnosis is needed before pointing to solely at the head gaskets.

It’s just odd the problem didn’t surface during your water-test otherwise.

Oh wow - that’s a good cost savings. I think between my husband and I we could probably replace them ourselves. Yes, at first we thought maybe an intake manifold crack? But we don’t know too much about boat engines... not sure if 6 quarts of water would get in that way. Or maybe a crack in the block expanded after engine got up and running a few hours? Guess I need to be patient and get some additional tests done at the shop that winterized it

Edited June 1, 2020 by MFK27

[Woodski]

Blown head gaskets between the middle two cylinders may not ingest water in to the cylinders, if the fire rings simply fail from hot running as noted above you will get a high speed misfire and intake popping.  The hard starting and of course having water blow out the spark plug holes indicate cylinder filling so don't try to start it  with water in the cylinders as that can bend a connecting rod or crack a piston.  There are lots of cavities that retain oil when the engine is shut off so as noted it will take a while to purge all the water mix.

I second the comment on 700 hours, many water ski schools will put 2,500 hours on their engines prior to needing any significant work.  To create the type of failure you are seeing it usually takes some out of normal operation event to cause it.  Typically it is an overheat or freeze event.  Raw water pumps are not the most robust and shredding an impeller, filling the system with weeds that cuts off the supply water leads to running hot.  Poor winterization practices can lead to water freezing in the block.

If you tackle it yourself, you don't need to know a lot about boat engines, just make sure as you go to replace the parts you select the key ones that are marine v. automotive (and head gaskets happen to be one of them as they have stainless steel fire rings).  If you know how to tackle a small block Chevy / GM your are equipped with the knowledge you need.  Simply ask here for the marine to automotive difference, many members on this thread know.

Edited June 1, 2020 by Woodski

[MFK27]

12 minutes ago, Woodski said:

Blown head gaskets between the middle two cylinders may not ingest water in to the cylinders, if the fire rings simply fail from hot running as noted above you will get a high speed misfire and intake popping.  The hard starting and of course having water blow out the spark plug holes indicate cylinder filling so don't try to start it  with water in the cylinders as that can bend a connecting rod or crack a piston.  There are lots of cavities that retain oil when the engine is shut off so as noted it will take a while to purge all the water mix.

I second the comment on 700 hours, many water ski schools will put 2,500 hours on their engines prior to needing any significant work.  To create the type of failure you are seeing it usually takes some out of normal operation event to cause it.  Typically it is an overheat or freeze event.  Raw water pumps are not the most robust and shredding an impeller, filling the system with weeds that cuts off the supply water leads to running hot.  Poor winterization practices can lead to water freezing in the block.

If you tackle it yourself, you don't need to know a lot about boat engines, just make sure as you go to replace the parts you select the key ones that are marine v. automotive (and head gaskets happen to be one of them as they have stainless steel fire rings).  If you know how to tackle a small block Chevy / GM your are equipped with the knowledge you need.  Simply ask here for the marine to automotive difference, many members on this thread know.

Okay, it gives me some hope that once we figure out this issue (hopefully not as terrible as a cracked block) this engine will still have many hours left as long as we maintain it properly. 
 

good to know about marine to automotive differences. With that in mind, it might make more sense to have the Marina who winterized or maybe a different one dissemble the entire engine, take off the heads and examine / perform a leak down test so we actually pinpoint the issue before committing to the major/expensive work of replacing the head gaskets. So if it is the head gaskets we can do them ourselves. Thanks a ton!

[Eagleboy99]

15 minutes ago, MFK27 said:

With that in mind, it might make more sense to have the Marina who winterized or maybe a different one dissemble the entire engine, take off the heads and examine / perform a leak down test so we actually pinpoint the issue before committing to the major/expensive work of replacing the head gaskets.

They should warranty their winterization work.

[MFK27]

8 minutes ago, Eagleboy99 said:

They should warranty their winterization work.

Right, they do. Based on my research, if the head gaskets are blown that doesn’t necessarily mean poor winterization? So I’m thinking it might make sense to try and do those ourselves if that’s truly the issue. 

[Eagleboy99]

I blew the head gasket on  my boosted turbo sports car years ago - it was due to overheating.  I would think that your first step is determining if it is the block or not.  If the shop that winterized says it is the gaskets, and they replace them and it still a problem, I guess they will have to replace the block.

[Michigan boarder]

48 minutes ago, MFK27 said:

 

good to know about marine to automotive differences. With that in mind, it might make more sense to have the Marina who winterized or maybe a different one dissemble the entire engine, take off the heads and examine / perform a leak down test so we actually pinpoint the issue before committing to the major/expensive work of replacing the head gaskets. So if it is the head gaskets we can do them ourselves. Thanks a ton!

Once they have gone this far you might as well have them complete it and reasseble though, since a lot of the labor $$ will have been already spent.