Volvo AQ125 died today on the water....hydro lock?

[2stroke1971]

We were out on the bay today...ran out to our fishing spot, about a 10 minute run....boat was running a bit hot, but not too bad...
Went to move after an hour and it would not start. I pumped the throttle a bit and it fired up but sounded rough....left it in neutral and gave it some more throttle and it started to run a bit better, started to clear out....so I took the throttle back down to idle and it died again. Cranked it again, would not start.....
Then I opened the throttle about half way, and cranked it....we heard a water sound....sploosh...but it would not start. I opened the hatch and it looked for all the world like it back fired water through the carb?!?
DId not try to crank it any more after that....got a tow into port...once there, we tried to crank it over and it wont turn. THe starter is engaging, but it appears the motor is locked.

So it probably has water in a cylinder...? But how does this happen? Sucked some coolant in through a failing head gasket perhaps?

Timing belt apeared intact...I suppose I will pull the head off of it and give it a look...

 

[jerryjerry05]

Pull the plugs and see if there is water in the pistons.
Turn it over and see if it comes out the plug holes.
Timing could have jumped?
Check the marks on the belt.
Taking the head off should be the last thing you do after checking everything.
How old is the manifold?
They usually last 15-20 years depending on salt or fresh water?

 

[2stroke1971]

The more I think about it, I wonder if it could have locked up on fuel...I pumped the throttle, then started it with the throttle open, etc....
What splattered all over the motor seemed like coolant though...not that I looked at it that closely...it was getting dark and conditions were getting a bit dicey on the water as well.
I will pull the plugs out today and see if i twill turn then and see what comes out of where....
Ive had a timing belt break at 3500 rpms before, and no damage...not sure if the AQ is an interference motor or what...I would have thought if it was I would have bent all the valves a couple years back when that happened. Will check the timing either way.

Just disenchanted with the whole thing. We've only had it out 5 or 6 times the last two seasons. Time was, we would fish once a week. Then my better half got sick (still not 100 percent) and we missed a whole season over that...non use is a killer for sure.
Add to that the fact that I can no longer keep the thing at my house....it now stays in a storage yard about 30 minutes away. I used to be able to tinker with it whenever I had a few spare moments. The way my life has been, it's hard to get a half a day free and drive out there and work on the thing. I always forget a tool or something and instead of just walking back in the house to get whatever it is...

Ive been working 60 to 80 hours a week for the last year and a half...whenever I do get a rare weekend off...lets just say I have too many hobbies. Too many motorized oddities that demand attention. Whenever I have the time--no money----whenever I have the money---no time.

Anyway, thanks for the reply! Will update!

 

[2stroke1971]

I pulled the plugs and sure enough some water came out of the two rear cylinders...(I think) at least one of the rear ones....Oil looks fine...The expansion tank was up to the rim....If I had lost coolant, between what it spewed out on the water and what came out of the cyclinders today, I would have seen the level had dropped a bit, but no.
No oil in the anti freeze....no anti freeze in the oil....
GIven the way it has been running a little warm....Im gonna say it was sea water it gulped, and through a bad exhaust manifold. WHo knows how old it is...Ive had the boat for 4 years... I bought the boat from a young man who had taken his Father's old boat which had been sitting for years and tried to fix it up....he gave me a list of stuff he did, and the manifold was not on it...the manifold could be 20 years old for all I know.
I sprayed some penetrating oil in the jugs and then some carb cleaner, starting fluid, etc....and blew it out with no plugs in it....
WIth the plugs in, it cranks seemingly normally...BUT---no SPARK now! So Id expect it would run---but now it has no spark. Jeez. I dunno. GOnna drag it back to storage now and maybe attack the spark issue this weekend.
My better half's confidence in the old boat has been shaken... not sure what I want to do with it. I think Id have to spend about 5 or 600 to put it right.......

 

[captmello]

I feel your pain. At one time, I too, couldn't store my boat at my house. How can you keep an old boat going when you can't work on it! Its sounds like a timing belt issue to me. Get the cylinders dried out ASAP!

no spark is usually bad points, or something simple.

Good luck, let us know what you find.

 

[jerryjerry05]

Like Mello said , dry out the cylinders and spray some oil in the cylinders.
The motor can seize in a very short time .

 

[2stroke1971]

Well.
A small bit of back story. Over the week of the 4th, we had the boat on vacation with us. Sometimes, we would get shocked just a bit from touching the window frames. Figured I had a short and meant to track it down. While I was in there the other night, I found a wire hanging free, it had 8 volts with ignition on...light blue--the oil pressure switch wire. That may have been my jolt....not sure if that ties in to my ignition dying.

Of course, Id like to reverse engineer a solution that makes what happened cheap to fix, etc, but I love figuring this stuff out sometimes.

I am starting to think that the hydro lock was secondary. My ignition system is not working. No spark. The hydro lock did not cause the spark to go away. (well, once on my old Dodge, a backfire DID snap the spit off the end of my distributor shaft..)

My ignition system did not decide to fail at just the same time I got the hydro lock. It was being hard to start...perhaps in the last sputtering backfiring gasps of my ignition system after cranking and cranking (sometimes with the throttle open all the way) it sucked the water in.

I sprayed oil in the cylinders, then some carb cleaner down the throat of the carb and intake....blew it out and then again...cranks normally.
Pulled a plug--no spark...pulled the coil wire off the distributor and laid it close to an intake bolt...no spark there. I do have 12 V at the coil with ignition on.
Primary tested ok, Secondary seemd a bit high.
I have an electronic ignition, converted by the previous owner. Not sure what variety (if there was more than the pertronix or whatever it was called..)
But with nothing coming out of the coil, I am suspecting the coil.

Im pretty sure if I get spark, it will run. Brings me back to the hydro lock. I was under the impression that the only way sea water would get in was if the manifoldle was bad...if the jacket was rusted through...but there is, of course, that spot at the end of the manifold where the exhaust AND the seawater both exit through that rubber donut into the outlet....I suppose seawater could backup there...it was a very rough day, we were getting tossed around pretty good...rear of the boat dipping and rising alot...3 to 4 footers at some points. And no, I dont have a flap on the exhaust. (Ive read many conflicting posts about that issue alone)...but given those conidtions and the fact that I was cranking and cranking and that it was sputtering and backfired, I could see it slurping some seawater... I would imagine cranking the motor would be moving some seawater through the manifold and with it not running and then backfiring.....gulp.

As for the running a bit hot, my belt was very loose and Id bet it was slipping on the engine water pump. (some rubber dust there)

Now I have to think about what to do. Getting some pressure to just sell it.

Thanks for the replies so far! Next will be getting a coil I can use to test it with.

 

[TonyR64]

If the valvetrain is good, you cannot hydro-lock an engine. The exhaust valve starts to open before the piston reaches bottom dead center and before the intake valve closes. So there is no way to hydro-lock an engine. A top fuel engine cylinder is 99% filled with liquid fuel and they don't hydro-lock.

 

[Maclin]

Tony, that is just bad information. Engines hydrolock on the compression stroke. If there has been sufficient water intrusion into a cylinder and it is ready for a compression cycle then it hydrolocks. The water can come in when the engine is off. If the water comes in while the engine is running then it tries to keep going, but if it dies then the water will probably be in a cylinder ready to compress next time it is turned over and hydrolocks. Gases can exit easier than solids, and there is just not enough overlap time to get any water out on anything but a full exhaust stroke, and not every cylinder that gets water in is at that point.

 

[Maclin]

I think when a top fuel engine hydrolocks they call it a GRENADE. If the fuel load does not ignite, then more tries to come in on the next several intake strokes the engine does not survive.

 

[2stroke1971]

So, it got worse somehow.
Last weekend, it was cranking over just fine, but no spark. Today, I went out the storage yard with a spare coil to test that out...and the battery was stone dead. Put another battery on it, and right away, the terminal arced and got VERY hot. Pulled it quick. Tapped the terminal on briefly and along with the arcs I heard a clicking. It was the starter relay.
I pulled the starter switch and put the meter on it, and it was conducting as if it was in the start position! So, at some point this past week, my starter switch shorted out and it must have cranked and cranked the motor until the battery died?!?!? Or something worse....I got the switch to behave, and put the fresh battery in...everything worked but when I went to crank the motor over, the same thing happened......volts dipped low, battery got HOT and nothing turned. The starter was not even engaging...no clicking from the solenoid, although the starter relay was clicking.
SO engine stuck? Well I put a wrench on the main pulley and it did turn, although it felt a bit funky....and guess what? The timing belt was NOT turning. I know if you go the wrong way it will jump and all, but I was going the right way, and got the pulley to turn about 3/4 a turn around....then it felt like it was binding up...I have no idea what the heck happened here.
MAybe the timing belt skinned some teeth off somewhere....it's not broken that I can tell, I cant pull it off/out...it feels tight as it should...and it even slacked up a bit when I turned it the opposite way just a bit.
I guess Im gonna have to pull the belt, see if the bottom end turns, and then see if the top end turns.......I wish I knew if the timing belt was turning last week when I could crank the motor over...if not, then thats why I had no spark...but now the starter isnt even trying....Bizzare. What it god's green acre happened with that ignition switch. My god, it might have cranked for 15 minutes and burned up the starter, and skinned up the timing belt....what the heck?!?!?
Im just about ready. Craigslist. Cheap.

 

[2stroke1971]

thought I would update this thread.
It broke down on the water, would not start, then hydrolocked.
Back at the yard, it was not getting spark as I started to diagnose it.
A week later, my starter was shorted out...burned up.

I thought my ignition failed and that had caused the break down.
However, as I went through the motor, turning the main pulley with a wrench, I noticed the timing belt was not moving. I cut the belt off and sure enough....ALL the teeth were just about worn off and a 6 inch section down at the main pulley had worn completely smooth.

THAT is what made it break down on the water, why I lost timing and sucked in some water, and why there was no spark when cranking it over back at the yard.

The night we got towed in, it started storming badly just as we got the boat on the trailer and I forgot to pull the drain plug.....THAT is what fried my starter, there was so much water in the bilge a week later when I went back.....(it rained the night I came in, and lots that week)

So....right away when it broke down, my better half was ready to get rid of it. It costs me $130 a month just to park the thing. We hadn't had it out much at all this year or last, and we were teetering on a channel and had a big ship blow it's horn at us when we were broken....so we planned to sell it...at first I was just going to put it up as it was, with a broken engine....but then i decided to get it running again. Add to the situation a minor cash flow crisis....So I set about working on it with the intentions of selling it.

I fixed the starter already....I was out there last night putting it on, and it was a cool night with a good breeze blowing. Sitting there, working by my LED fishing light, it sure felt like I was on the water at times. I sat back on the rear seat for a moment and I could just feel how relaxed I would get out there on the water. And then Im haning there, half inverted, bolting the starter on thinking about selling it and it was just sad. Not sure what Im gonna do at this point.

 

[500dollar744ti]

Replace timing belt and go boating! The engine is not interference so you just slap on a new belt and go.

 

[jrwarrick]

2Stroke1971...hate to hear of your run of bad luck. I'm scouring the forum looking for solutions because I'm having intermittent fuel/power problems with mine. You haven't posted anything recently and I'm wondering if you've have any success in getting your boat repaired and back on the water?

 

[2stroke1971]

I replaced the timing belt....took a while to get her fired back up. I wound up having to clean out the carb...it had some white stuff in it...might have been salt precipitated out from the water that got in there...it had clogged up the accelerator pump passageways and check balls, etc..(remember, it had backfires WATER out of the carb!) also changed the oil...some water got into it from the cylinders,,,,.

Took it out mostly to shake it down and it runs great. The starter is crappy...I put another used solenoid on it and it;s a bit goofy...sometimes it does not engage. Just need to buy a new one. Ive had it up for sale for almost two weeks and not one call about it. (not worried about that----sort of hope no one calls)

However, in the course of fretting over it for the sale, I have found some things that need attention... By the time I do everything to it that I want so that I feel good about selling it, I should just keep it....Really though, the sale was not brought on by "I cant fix it"...more like I hate to fix it again, only to have it rot away some more when we dont use it much. So, we had to take a hard look at why we stopped using it so much.

I think the key will be finding a place to keep the boat that has 24 hour access. We like to hit the water an hour before sunset and fish until the wee hours. With our current storage facility, you have to be in the gate by 10:00pm...(its not a marina, just a storage place that also has parking spots) We used to just put the boat at the house when done and then drive it back to storage the next day, but the parking is so bad at home that there is almost NEVER anywhere to put the boat at the house late at night.

Im just playing it by ear for now......