1989 454 hydrolock questions
07-16-2012, 08:08 PM
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1989 454 hydrolock questions
1989 454 600 hours
No sooner do i figure out my over heat on my starboard engine...my port motor hydrolocks...i was out one day ran great...when to start it the next and starter makes an awful grind
symtoms...
just starbord bank of cylinders...all filled with water..
with riser and manifold off water leaking out of cylinder 8 and 6 valve holes i dont know if its becuase the motor leans back that its toward the back cylinders
what ive done:
taken exhaust off starboard side...pulled all plugs...disconnected all water lines...drained motor of oil...had some water in it...even though it was not run...never got milkshake. i refilled the motor with oil...left off all water lines..sprayed fogging oil into the cylinders and poured some oil into the carbureter...turned the motor over on the starter for about a minute to recoat all walls and make sure nothing would rust...
whats next...im assuming head gasket or cracked head...is this correct or could it be something else...i will begin teardown as soon as i hear anything from you guys...id would like to try and save the motor and get a few mor years out of it...i just can't afford a new motor...right now...what do you guys think
No sooner do i figure out my over heat on my starboard engine...my port motor hydrolocks...i was out one day ran great...when to start it the next and starter makes an awful grind
symtoms...
just starbord bank of cylinders...all filled with water..
with riser and manifold off water leaking out of cylinder 8 and 6 valve holes i dont know if its becuase the motor leans back that its toward the back cylinders
what ive done:
taken exhaust off starboard side...pulled all plugs...disconnected all water lines...drained motor of oil...had some water in it...even though it was not run...never got milkshake. i refilled the motor with oil...left off all water lines..sprayed fogging oil into the cylinders and poured some oil into the carbureter...turned the motor over on the starter for about a minute to recoat all walls and make sure nothing would rust...
whats next...im assuming head gasket or cracked head...is this correct or could it be something else...i will begin teardown as soon as i hear anything from you guys...id would like to try and save the motor and get a few mor years out of it...i just can't afford a new motor...right now...what do you guys think
07-16-2012, 08:23 PM
#2
First suspect would be leaky riser / manifold, especially if run in salt water. And yes, that would tend to fill the rear cylinders first. Compression or leakdown test will probably confirm if it is a leaking head gasket. Take a close look at that riser and manifold first, though - that is the #1 cause of hydrolocked motors.
07-16-2012, 08:41 PM
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with the manifold and riser out...i have water coming out of the number 6 and 8 exhaust ports...if i just leave the manifold on...i can watch it fill with water and leaking into the front two cylinders as well through the manifold...will do a compression test tomorrow...but would love whatever else information you guys here have for me
Last edited by formula18; 07-16-2012 at 08:45 PM.
07-16-2012, 10:23 PM
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I wouldn't waist the time with a compression test. If it leaking water you won't have any compression. Spend the time pulling the head off and you will know what your problem is. The faster you get it apart the quicker you can clean the water off and prevent rust. The biggest question is, did the hydrolock hurt the bottom end?
07-17-2012, 04:38 AM
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from what i hear big block heads don't like raw water cooling. they rot through way before the engine blocks. in the sportfish world there are NO raw water big blocks. get a pair of heads. the other one is just as bad-just hasn't popped yet...
07-17-2012, 05:19 AM
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ok i will pull the head and skip the compression test...I'm hoping I didn't hurt the bottom end...o never ran since it hydrolocked
Last edited by formula18; 07-17-2012 at 09:05 AM.
07-17-2012, 04:52 PM
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drain oil, or at least bottom quart or so if oil is brand new to get the rest of the water after you are done pulling heads. that block is tough. you didn't hurt it. what heads, peanut (330 hp) or square port (365 on up hp)?
07-17-2012, 08:05 PM
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ok i pulled the starboard head...the head gasket looked really good...as well as the head...the valves have some surface rust on them so i will take them to a shop along with the intake to be cleaned up....i don't get it everything seems really good...the only thing i didn't love was the intake manifold gasket...could that create a problem only on one side?
i do have one question though and maybe its just new to me(big block) what the passage for on the inside of the head...in the middle, along the intake runner. i count 4 exhaust ports and 4 intake ports but there is a square one in the middle that i can see a valve? maybe im wrong and i wonder if this could create the problem
(peanut port)
i do have one question though and maybe its just new to me(big block) what the passage for on the inside of the head...in the middle, along the intake runner. i count 4 exhaust ports and 4 intake ports but there is a square one in the middle that i can see a valve? maybe im wrong and i wonder if this could create the problem
(peanut port)
Last edited by formula18; 07-17-2012 at 08:34 PM.
07-17-2012, 09:20 PM
#10
That is the exhaust heat riser passage. It takes some of the hot exhaust and circulates it under the intake to warm the charge for cold weather operation. It can be useful on a car, but not needed in a boat. If you look at your gaskets, you should see a metal blockoff plate to keep the exhaust from circulating.
It could be as simple as an intake manifold gasket leak, but the heads should be closely checked, along with the intake manifold and exhaust manifolds / risers. If those risers are more than 4 years old running in salt water, they should probably be replaced.
It could be as simple as an intake manifold gasket leak, but the heads should be closely checked, along with the intake manifold and exhaust manifolds / risers. If those risers are more than 4 years old running in salt water, they should probably be replaced.
