My third Hydro-lock in my first year.

JohnEGraham

JohnEGraham

Active Member
Aug 5, 2008
1,013
Long Island, NY.
Boat Info
250 Sundancer 1998 5.7.
Engines
350 Merc / Bravo 3
:smt089Hi, I can't belive it but I just had my third Hydro-lock in my first year.
1) 10/2008. Bad Manifolds
Risers Replaced for $800 total plus extra= 3,865 of work
2) 07/2009. Cracked head. Most Likly due to bad Raw water pump, (overheat with out knowing it) New Head & full valve Job plus water pump and housing.$2120
3) This past Sat. 10/04/2009
Grinding Noise. Mechanic pulled plugs yesterday. Yes water:smt013
He said that the engine sounds terrible when cranking with the plugs removed. He will start breaking the motor down tommorow.
The boat has been running great. I asked him if the Exhaust Flappers? ( somthing I have seen on this web site ) He said they where checked.
Overall He feels bad and will not be charging me for his labor.
Any idears? ( other than I got the wrong mechanic ) I asked him to make shure the risers where correct

:huh:Thanks. John G
 
Last edited:
That's no good. Do you have any idea how it happened?
Come off of plane really fast?
Turn the engine off while underway?
Engine sputter and diesel when turned off?
 
Come off of plane really fast? NO
Turn the engine off while underway? Sometime there is a lot of seaweed in my slip so I will shut the engine off and pull the Boat by hand.
Engine sputter and diesel when turned off? NO
The Boat was running great when we pulled it into the slip.
John G.
 
I had a 1997 250DA 5.7 BIII and never had such an issue.
 
Another bad head maybe?
Sorry to hear that, but hopefully your tech takes care of you.
Best of luck.
 
Another bad head maybe? I guess anything is possible. The head cracked because of the unknown over-heating and Both heads had full Valve jobs. When the Head cracked it was a loud exhaust noise.
What I am looking for is other items which he should check?
John G
 
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Was the block checked for trueness after the overheat before slapping on a new head?
How could you overheat that badly without knowing it- no alarm sensors or gauge?
Where is the water in the cylinders- one side (same as before?), both sides??
 
What's above plus checking for the right ignition and valve timing. Was the timing chain disturbed?

But #1 would be bad exhaust system gaskets between the manifold, risers (if any), and elbow.

Best regards,
Frank
 
Hi, RE: Overheating. We put the boat away and it was fine. Never had any signs of overheating. The next day the boat started fine and we dove 200 yards out of the slip and up the creek ( no kidding) and then we started to increase speed and the Engine was 5x the standard engine noise the temp went from 120 to 220 all in 3-5 seconds then the alarm went off and the engine shutdown. (The cracked exhaust port was visible when the head was removed ) After repair the engine was running Great! quite and smooth better than before. We took a major trip from lindenhurst to Greenport about 7 hours round trip plus around 10 -1 hr trips to fire Island in the 2 1/2 months that we had the boat back the last time.
TIMING: Not 100% shure but the last time I looked at the engine stripped down, while waiting for the Heads to be re-done I believe the timing cover was there.
WATER: The first time water was on both sides. Other time will have to ask.
QUESTION: If its the risers gaskets gone bad would you only have water on one side?
Thanks John G
 
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Sound like you're going for an engine this time. $800 seems low for manifolds, risers, and elbows. Were they OEM? Was everything replaced? I'm very suspicious of the exhaust system.
 
fc3 said:
Sound like you're going for an engine this time. $800 seems low for manifolds, risers, and elbows. Were they OEM? Was everything replaced? I'm very suspicious of the exhaust system.
Click to expand...

Yeah if they were not touched after the reheat, the gaskets could have blown out, weakened or the risers themselves could have warped with the overheat.
 
JohnEGraham said:
:smt089Hi, I can't belive it but I just had my third Hydro-lock in my first year.
1) 10/2008. Bad Manifolds
Risers Replaced for $800 total plus extra= 3,865 of work
2) 07/2009. Cracked head. Most Likly due to bad Raw water pump, (overheat with out knowing it) New Head & full valve Job plus water pump and housing.$2120
3) This past Sat. 10/04/2009
Grinding Noise. Mechanic pulled plugs yesterday. Yes water:smt013
He said that the engine sounds terrible when cranking with the plugs removed. He will start breaking the motor down tommorow.
The boat has been running great. I asked him if the Exhaust Flappers? ( somthing I have seen on this web site ) He said they where checked.
Overall He feels bad and will not be charging me for his labor.
Any idears? ( other than I got the wrong mechanic ) I asked him to make shure the risers where correct

:huh:Thanks. John G
Click to expand...

What was the $3,865 in work for? Four grand to replace risers/manifolds (I hope not)?
 
I remember talking about the risers. They where all new and replaced the manifolds, risers, and elbows but I don't think they where Merc. I remeber him talking about different risers brands he would never use including the riseres that he took off my engine. Being new to all this I did not know how critical they are like I know now. Live & learn...
John G
 
Any chance the replacements were not tall enough? Fellow across the dock has some aftermarket manifolds and risers installed and the 6" spacer was left out by the mechanic. Caused a hydrolock on one of the engines.
 
Hard to leave spacers out on sterndrives. The system doesn't line up.
 
Thank you , Cap'n Frank for pointing out the error of my ways. I will endeavor to pay more attention to the size and engine configuration of the vessel before I open my mouth.:lol:
 
I know that I do have spaces because I saw all the parts off the engine and he said that the spaces will need to be replaced along with the other Exhaust parts manifolds, risers, and elbows. The Motor / Exhaust is being broken down this morning, I sould know by 12. Now I know how it feels to wait for a jury...$ or this $$$$. John G
 
Not that this could cause all your issues, but do you have the water thru hull at the transom plate (through the drvie) vs. a thru hull under the boat? Several inviduals have experienced the passage way to totally constrict due to corrosion I believe??

Double check that portion.

After all these overheat issues, you may be better off with just replacing the engine with a long block assembly.

Doug
 
The water through the drive. A bunch of small holes at the bottom / side of the drive
John G.
 
JohnEGraham said:
The water through the drive. A bunch of small holes at the bottom / side of the drive
John G.
Click to expand...

Ok, then look into the portion that comes through the drive to see if it has collapsed. That may have contrinbuted to one or a partial overheat.

Doug
 
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