Hydrolocked - now what??

[regal_bill]

Greetings all – I’m hoping to get some advice. This is for a 1990 Volvo 5.7 engine in a Regal Ambassador 233.

I took the boat to a new mechanic (the old one went out of business) to have a failing starter replaced. He reported that the engine was hydrolocked, that water came out of one cylinder (#3), and then it ran fine. I asked how water would get in the cylinder, he said something to the effect that it’s a one in a million shot, but water can leak into the boat, can come in through the carb and get into the cylinder, and that it’s fine now, and not to worry. I asked if water could be sucked in through the raw water system, and he said “not really”.

Reading up on hydrolocking, it seems that it IS something to worry a bit more about – especially since his “water coming through the carb” is virtually impossible in my case. And that water CAN come in through the raw water system.

I summerized the boat 7-10 days before taking it in, hooked up to a garden hose via muffs on the drive. It started up fine, ran to temp, then, trying to exercise the starter, I stopped and started a dozen or so times – start, run for 10 seconds, stop, start. Then I let it sit for 30 minutes, and started again. All of this was with no problem, so obviously no hydrolock.

I store the boat inside with a cover on. Even if water COULD get in through the cover, the decking channels the water out through scuppers in the transom. Even if a huge amount of water got in and overwhelmed the drainage system, it would only get into the engine compartment around the engine, not on top. This is why I say water coming in through the carb is virtually impossible. I don’t think it rained between taking it in and it getting worked on at the shop either.

So I’m open to suggestions on how water got in, and what I should do next. I plan to check the cylinders again, and change the oil and see if any water is in there.

One other thing I should note – over the winter, after winterizing, I noticed what looked like engine oil leaking out of the outdrive exhaust – probably a couple tablespoons worth. I asked the mechanic about that – he said it was fogging oil from winterization. I’ve never seen that before, but it’s possible that I lowered the drive a little more than usual, just enough to let it drip out instead of pool. I accepted the “fogging oil” answer as plausible, but with the water in the cylinder, I’m wondering if the two may be related and point to a bigger problem?

I appreciate any input – thanks!

Bill

 

[BRICH1260]

I think you need to find a new mechanic. You probably have a bad manifold, riser or gasket. it is very unlikely that water came in from the carb. You might try doing a compression check to see how badly damaged that cylinder is before planning on replacing the engine.

 

[alldodge]

Agree do a compression test to see if there is a problem with that or another cylin

If you find water in the cylinder again need to look into other areas

 

[LundAngler1650]

Change the Oil ASAP to...if the cylinder was actually full of water like he claims, your oil has been contaminated.
Do a compression test, and leak down test.
Possibly blown head gasket???

 

[Lou C]

There is a Mercruiser document out there that explains how water gets in cylinders, but most often it can happen from the following:
leaky manifold to elbow gasket---> puts water in cyl, then oil
rotted elbow or manifold--->same
rotted intake manifold---> puts water in the cam valley right in the oil, not cyls
cracked cyl head--->will put water in a cyl, then oil
cracked block--->same as above
blown head gasket--->same as above

as long as the engine has not been overheated and it was properly winterized the last 3 are unlikely but the first one is actually pretty common especially with wet joint exhaust systems.

I always fog my engine but never saw any fogging oil come out of the exhaust housing, in nearly 20 years worth of winterizing.
Look at the joint between the manifold and exhaust elbow, if you see rust trails on the outside, it could be leaking on the inside and run right into a cyl from an open exhaust valve.

 

[regal_bill]

Thanks everyone so far for your input. Thanks Lou for mentioning that you've never seen fogging out coming out the exhaust - neither have I in all the years of winterizing/fogging this boat. Of the possible causes you've listed, would any of those account the the water in the cylinder AND the oil in the exhaust?

 

[Lou C]

Well oil in the exhaust could have other causes....bad valve stem seals, worn/sticking piston rings for a few. Then if you had an engine oil cooler or power steering cooler if either leaks it may be possible to see oil in the exhaust.
I’d do a compression test and check the exhaust carefully. See if your motor oil looks milky same with power steering fluid

 

[regal_bill]

Oil and PS fluid looks fine. Water again in cylinder #3. Skipped the compression test because I'd be taking it into the shop (a different shop) regardless of the readings to have someone who knows what they're doing figure this out. I'll post results here for posterity. Thanks for the input...

 

[Lou C]

If you’re getting water in one cyl here’s what I’d do:
Remove the exhaust on the port side check for evidence of water leaking in. Look at the top of the center exhaust passage at the top of the exhaust manifold. If you see that look at the exhaust valves see if there is corrosion on the stems, if so might need a valve job. If no water evident in the exhaust; re-assemble with new gaskets and get some clear plastic tubing about 3/4” inside diameter. Replace the hoses feeding the exhaust manifolds from the thermostat housing with the plastic tubing. Run the engine in the water long enough so that the engine fully warms up & the thermostat is open. Now look for bubbles in the hoses feeding the manifolds. If you see this you likely have a leaky head gaskets or a cracked cyl head or both. The bubbles are exhaust gas getting into the cooling water flow from the combustion chamber via a leaky head gasket. A compression test sometimes but not always will point to a leaky head gasket but water in a cyl or exhaust gas in the cooling water are true signs. These tests you can do yourself. At most you might have to pull the cyl heads and get them checked out by a machine shop.

I had water in a cyl and in the oil did all these tests and found that both head gaskets were blown probably from a past overheat 3 years prior to the water in a cyl. Checked exhaust and the water was not coming from there. The bubbles in the cooling water revealed the problem not really the compression test (normal). So I wound up installing a set of remanufactured 4.3 V6 heads, and still running well 4 years later. The old heads both had cracks and the cooling passages had gotten eroded by years of raw water cooling.

 

[Augoose]

You are getting great advice- keep positive and you'll get it figured out!

 

[regal_bill]

If you’re getting water in one cyl here’s what I’d do:
Remove the exhaust on the port side check for evidence of water leaking in. Look at the top of the center exhaust passage at the top of the exhaust manifold. If you see that look at the exhaust valves see if there is corrosion on the stems, if so might need a valve job. If no water evident in the exhaust; re-assemble with new gaskets and get some clear plastic tubing about 3/4” inside diameter. Replace the hoses feeding the exhaust manifolds from the thermostat housing with the plastic tubing. Run the engine in the water long enough so that the engine fully warms up & the thermostat is open. Now look for bubbles in the hoses feeding the manifolds. If you see this you likely have a leaky head gaskets or a cracked cyl head or both. The bubbles are exhaust gas getting into the cooling water flow from the combustion chamber via a leaky head gasket. A compression test sometimes but not always will point to a leaky head gasket but water in a cyl or exhaust gas in the cooling water are true signs. These tests you can do yourself. At most you might have to pull the cyl heads and get them checked out by a machine shop.

I had water in a cyl and in the oil did all these tests and found that both head gaskets were blown probably from a past overheat 3 years prior to the water in a cyl. Checked exhaust and the water was not coming from there. The bubbles in the cooling water revealed the problem not really the compression test (normal). So I wound up installing a set of remanufactured 4.3 V6 heads, and still running well 4 years later. The old heads both had cracks and the cooling passages had gotten eroded by years of raw water cooling.

Hey, Lou, I appreciate the detailed post. While it sounds like this is all something I could do, it goes beyond my comfort level. And at the end of the day, whatever I would find, I would still need to take it into the shop to get fixed. So I'm opting to just let them do the troubleshooting as well. At this point I'm hoping for just about anything but a cracked block. I did have an overheat a few years ago - maybe that was the root cause as you suspect in your case. Pretty sad when what I'm hoping for is blown head gaskets...

 

[regal_bill]

As promised, posting the mechanic's findings for posterity. The heads on the port side were corroded, and the main gasket wasn't sealing properly, allowing water to enter the cylinder from the water jacket. It's unclear if the gasket went bad, allowing water in, causing the corrosion, or whether the initial fit was off, allowing gradual leakage, or if there was unnoticed corrosion on the head when it was last removed, making the gasket fit off. New heads, a half dozen sets of different gaskets, and $2500 later, and I should be good. Still beats a cracked block....

Thanks again everyone for your input!

Bill

 

[Lou C]

sounds good, glad they could fix it without replacing the short block. Total parts price for my DIY job was
$550 for a pair of reman V6 heads
$120 for a set of Fel Pro marine gaskets (head, intake, etc)
$100 for a set of ARP cyl head bolts
So, about $850 for parts the rest was my labor. In all not a bad job. I was amazed actually that it came apart without breaking any bolts after 15+ years in salt water.

 

[regal_bill]

Yep, no denying that if you can DIY, you'll save a bunch. Total labor on my $2500 was $1060 for 9 hours. I would totally work for 9 hours to save the money - and have, on this boat - but I just don't know what I'm doing enough to take the engine apart.

 

[Lou C]

This was actually the first engine I've taken apart in my many years of maintaining my own vehicles (since 1972). I figured that I have nothing to lose and it would be a good learning experience which it truly was. I had to use an impact gun to get all the cyl head bolts out, and the intake manifold gaskets were baked on like kryptonite. Other than that, easy.

 

[regal_bill]

Inspiring....