Hydrolocked, high oil level, why?
 

Motor is hydrolocked & the oil level is high. It wasn’t overfilled & there are no signs of water in the oil. Why would it go up like that w/ no signs of water? Compression varies from 115 to 160psi. The motor only has 100hrs on new top end. It has the 454HO cam, which I thought, shouldn’t have any reversion issues but now I wonder. Boat still has through prop exhaust.

My daughter was pulling me when she ran aground in the mud. I think this probably blocked some of the water passages & overheated the motor & thus blowing the head gaskets. Both sides of the motor had water in the cylinders. Just want to make sure this is a overheat issue & not something else like reversion, detonation, etc. What all should I check?

I have heard of this happening a couple of times
from people I know after they overheated and shut the
engine off.

What happened was that the
engine "dieseled", ( ran on) but kicked backwards,
water is then drawn back into the exhaust.

So the motor ingested all the water between the flappers in the y-pipe & the risers?

Any idea on the high oil level?

If you are sure it is not water.... then its probably fuel... pull the dipstick and take a wiff... does it smell like gas?
If so, GET THAT CRAP OUT OF THERE..... fuel dilluted oil will trash a motor fast. Since you have a new top end, did the carb get rebuilt? how is the tune? What do the plugs look like? are they all fouled out?

Ahh... just read yo overheated and had water in the cylinders.... that will do it, it will clear the rings and run down the cylinder walls into the oil pan... but you said earlier it was NOT water? Its either water or fuel; both equally destructive.

you have either rotted away an interior section of the intake manfifold towards the rear cylinders or rotted away a part of the exhaust manifolds and filled up a couple of cylinders w/ water which ran down by the rings and filled up the oil pan. do two things right away...

get the plugs out and rotate the motor by hand until the cylinders are clear and fill w/ oil and then get the heads off ASAP. if the motor won't tturn by hand then you have either rusted the valves to the guides or the rings to the bores and every day you wait costs you many more dollars in repair.

if you rust up those bores badly it goes from a couple hundred to fix to a couple thousand very very quickly.

I'll drian the oil & whatever else is in there & pull the heads tonight. Its not milkshake & doesn't smell like fuel. All the plugs where wet & showing signs of rust. The motor freely turns over w/ the plugs removed.

Without cooling water in the exhaust, the
flappers in the y pipe don't live too long.


The one's that I had dealings with were sea pump
failures, and after the impellers were changed,
and the water was purged from the cylinders,
and oil was changed, they ran fine.

The key here is that this was all handled quickly,
they didn't let things sit and rust.

What signs did you check for water in the oil? My exhaust leaked and put water in the oil pan past the rings. The dipstick looked normal. For some reason the oil pushed up into the dipstick without any water. Rub your finger around the oil fill hole (inside) on the valve cover and check for cheese.

No water bubbles, no milkshake... just looks like clean oil. I would think it would have mixed up when I did the compression check & looked like milkshake. I'm going to run home @ lunch & drain it.

Should I pour diesel in it & crank it over & then drain that? I read that will displace any water & lubricate everything?

the ones that i have seen like this have the water and oil seperate cleanly w/ the water sitting on the bottom. when you drain it, you will see clean water come out... then the oil. after you get the water out and fix whats wrong, i would just run some clean lightweight oil thru it for a couple of changes... just run it to temp at idle for 20 or 30 minutes then drain then repeat .

the trick is to id what went wrong. i have seen a lot of them rot the intake manifiolds away near the rear intake ports if its a salt water boat.

no guesswork when you do this... you have to know where the water got in from 100 % certain... no maybes

Like steve said, the water is sitting in the bottom of the oil pan. It probably didn't have time to mix up a lot with the oil. Most likely the bearings are trashed now and you'll need a complete rebuild.

Oil floats on top of water !!!

Drained the oil & there was water in the bottom of the pan. Not much though, maybe a quart or two max.

I'll pull the heads & check them out tonight.

454/502 HO cam 24502611 6 192, 2611, 261668-
210-230*
511/540”

Reversion shouldn't be an issue w/ the above cam, huh? Its ran for 100hrs so seems like it would have been a problem sooner if there was a chance of reversion.

You overheated the motor right and found water in the cylinders? Have you had water in the cylinders before?? Pretty clear cause and effect to me. One thing would be to try and see if the exhausts are cracked from the overheat before taking the heads off. Exhausts have to come off first anyway.

BTW, not much water in the pan??? A quart or two is a lot.

If you overheated the engine you could have warped a head or blew a gasket. Take the heads to a machine shop and have them checked. Reversion would act different than what you are seeing. Reversion would milkshake your oil and you would see moisture in the engine not water in the pan. What engine do you have? I have a complete set of heads for a Gen V 330HP with a fresh rebuild. Good luck, I have been there.

pulled the heads. both head gaskets blown. no noted cracks on the exhaust, heads, cylinders, or cheese under the valve covers. With a straight edge I couldn't see any signs of warpage on the heads. I'm going to take them to the guy who ported them for a second opinion.

the motor is a stock gen V short block, w/ ported vortec heads, 496 exhaust, 454HO cam, performer manifold.

I wastn't in the boat when it stopped. I first thought it was just a dead battery so I never noted the temp. This is my best guess so I want to rule everything else out so it doesn't happen again.

i think it extremely unlikely that failed head gaskets will put clean water in your cylinders sufficient to lock them up and run down into the pan.

but who knows. i suppose its possible.

only takes a small amount of water to lock it up.

Probably also pushed the head gasket into the valley where the bolt pattern is lacking on a BBC which actually is sealing the water passages. Definitely get a bunch of water in the pan with that scenario. Don't know about how much water will leak into the cylinders with a head gasket problem but I got a quart of water in the oil pan with an exhaust manifold leak by pushing past the rings.

I'm open to suggestions? I noticed the Knock sensor was disconnected when I tore down the motor last night. My guess is the default is the reduced timming mode. It didn't seem to run as strong that day so I'm pretty sure it was in the reduced timming mode.

could detonation somehow cause the this?

It's not very likely to happen to both gaskets at the same time. Are you 100% sure the correct head gaskets were installed?



Darrell.

Were was the gasket failed? It sounds like it was ingesting a small amount of water prior to the over heat ( water jackets/ bad flappers). You can not compress water so the cylinder pressure rises and you get failures. Both sides though makes one wonder? It is possible the over heat issue was extreme. Make sure they pressure test the heads as well as checking the surface. Check your sea water pump, if that is smoked then you had an extreme over heat. ouch. Check the exhaust flappers ( they should be replaced any way after a good over heat). Check the exhaust system for water leaks into the exhaust side from the water side.

Also with that much heat and cylinder pressure the top half of the rod bearing and the bottom half of the main bearings have a tendency to flatten out (squish). So do not be surprised if your oil pressure is a little lower than before once it is back together. Use an oil primer to prime the engine oil system before the first restart.

Let us know how you are making out. Good Luck.

Man I feel for you!

I blew a starter the other day and thought it was because of the compression! Someone mentioned Hydraulic Lock Up while I was complaining abou thow crap my starter was so I raced down to the work shop and got to work ripping the heads off...
The engine turned after I cleaned it all out, drained everything and dried things up. Fortunately for me, this happened on a hose so the water was fresh and clean.

Here's the Starter and here's what I found:

The head gaskets are the Felpro 17042 (.038-.042” Gen 5 & 6) which are slightly thicker than the stock. The original motor w/ the peanut heads had .027” gaskets. The gaskets failed between the cylinders.

The rubber coated exhaust flappers in the y pipe were intact & seem fine. Not brittle like it was overheated.

No sea pump but the impellor in the outdrive (king cobra) had some sand in it. The impeller itself had a couple cracked tips but overall was not trashed. The o-ring seal on the housing was bad.


Jaayteee “What happened was that the
engine "dieseled", (ran on) but kicked backwards,
water is then drawn back into the exhaust.”

Not knowing exactly what happened scares the crap out me but the “diseled” theory seems to make the most cense.

Ghostrider. Looks like we have the same problem. what caused yours?

My own stupidity. Had the timing wrong on the distributor when going for start up after a cam / intake / carb swap. Finally sorted the carb out then when I went to start, she back fired due to timing, but was on the hose so when she spun the wrong way she took out the starter and flooded a couple of cylinders. I didn't notice or even think about it. I just checked the timing, adjusted the distributor and went to crank again. That's when I noticed the starter had crapped out.

I went home, posted on here about how crap my starter was and MER Performance rightfully suggested what might have been the root cause. I screamed back down to my workshop and tore the engine down to find that he was completely correct! :ernaehrung004:

I've cleaned it all out, drained it, spun it, oiled it, drained, spun it and done it all over again just to be sure. Now I'm waiting on my new starter to put it all back together again and see if I can't screw something else up! :drink:

How's your coming along?

John

Got the head gaskets in Saturday & got the heads back on. Compression is back & consistant.

Cracked my Performer manifold trying to E-Z out a vacuum plug. Ordered a new Air Gap RPM which should be in tomorrow.

Installing Corsa diverters & fighting the rigging.

Should be up & running by the weekend.

What cam & manifold did you switch to? You were running the Air Gap & 731 cam correct?

Sort of, I had a Victor Jnr Manifold and the 731 cam but I was using the stock cam for break in as the 731 cam hadn't arrived by the time I wanted to start. I've now got the 731 cam but I'm testing a Crower with similar numbers (lift and duration) to the 731 but it's only got 110 Deg LSA. I also just acquired a 741 to put in next but I need the correct lifters and to re-check my springs for that!

The Air-Gap is on now with a 2" spacer and the Holley 850 HP, when the new starter arrives, I'll let you know if it all works!

Good luck with yours, keep us posted!