Had a bad weekend guys. Got a sick small block Chevy in the garage right now. Driving my 70 Blazer on Saturday and think I just experienced my first blown head gasket. Was driving it with a heavy foot and... bam. Engine started running bad and smoke out the exhaust. Pulled over and collected my thoughts. Tried to start the engine to limp it home, and it cranked for a few turns then hydro locked. Towed it home and pulled spark plugs. Milk coming out of #7 cylinder. Drained the oil. A ton of coolant came out with the oil. Sprayed the cylinders down with Sea Foam and spun the engine for a second or two. A guy at work told me to drain the radiator and change the oil, then run for a minute or two to burn off the excess coolant in the engine. Then he said to pull the engine and check for bent rod or cracked block. Do I need to do this? Would the starter have enough torque to bend the rod on it's own? Can I replace the drivers bank head gasket and see what happens? Any recommendations? Engine is 383 stroker/ .60 over/ iron vortec heads/ 9.5 compression ratio. Thanks!
CK5
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Blown Head Gasket -- hydro lock
- Thread starter andyweder
- Start date
cegusman
3/4 ton status
I would just pull the motor and do a tear down. Replace what needs to be replaced. I would hate to turn it over and cause more issues
I don't think the starter has anywhere near enough jam to hurt a hydro-locked motor...or enough speed. Hydro-lock damage usually occurs when the motor is running and takes in a beakful of water.
When the head gaskets went on my 6.2 it hydro-locked only when warm. I managed to re-fire it twice like that by hitting the key, waiting, try the key again, waiting, and finally the coolant in the cylinder would slowly get past the valves (and where-ever else)and it would fire on the next revolution. I did the head gaskets and it's been running like a dream ever since.
Rene
When the head gaskets went on my 6.2 it hydro-locked only when warm. I managed to re-fire it twice like that by hitting the key, waiting, try the key again, waiting, and finally the coolant in the cylinder would slowly get past the valves (and where-ever else)and it would fire on the next revolution. I did the head gaskets and it's been running like a dream ever since.
Rene
Water DOES NOT compress. If the cylinder has enough water in it and you try to crank the starter IT CAN and usually does bend connecting rods, explode pistons, blow holes in the cylinder wall(s). 
cegusman
3/4 ton status
Water DOES NOT compress. If the cylinder has enough water in it and you try to crank the starter IT CAN and usually does bend connecting rods, explode pistons, blow holes in the cylinder wall(s).
x2 have seen it way to may times down here wheeling in the creeks.
4xcrazy
3/4 ton status
I had a mild leaking head gasket on the original motor in my Burb, kept losing water, didn't know where for awhile, when it started getting worse, i would go out in the morning to start the engine and it would turn over a rev or and just stop, i bumped the started a couple of times, it freed up and would usually start.
Until it finally got so bad that it just would not move any longer, that's when i started pulling plugs and found the #8 cyl to be full of water. did not damage anything on the motor, just a failed gasket, i could have cleaned out that motor, had it rebuilt/freshened up and all would have been fine.
I am another to believe the older starters doe not have enough torque to do major damage to an engine, unless it's some sort of after market high torque or maybe even the newer style high torque starters.
Until it finally got so bad that it just would not move any longer, that's when i started pulling plugs and found the #8 cyl to be full of water. did not damage anything on the motor, just a failed gasket, i could have cleaned out that motor, had it rebuilt/freshened up and all would have been fine.
I am another to believe the older starters doe not have enough torque to do major damage to an engine, unless it's some sort of after market high torque or maybe even the newer style high torque starters.
Thank for the advice guys. Just a stock starter, so a guy wouldn't think it would have enought torque to bend a rod, but I guess anything is possible. Going to tear it down over the next couple nights and put on a new head gasket. I will post the compression test results after work is completed. Hopefully everything checks out. Maybe I'll keep my foot out of it for a while, but that's doubtful.
cegusman
3/4 ton status
A stock starter will do it. It really doesn't take much to bend **** when bound up.
I remain doubtful, first off I don't think the rods are that weak...if they were the stresses of running would kill them in minutes. Second, when most people turn the key and the motor goes 'uhhh' they don't normally lean on the key for another 5 seconds.
My buddy had an 89 1/2 ton work truck with a 4.3 V-6 that lost the head gaskets. The fact it hydro-locked was what finally clued him in, and he found out it was hydro-locked after the starter broke. Rods and everything else were fine though, and it went another 60,000 miles before blowing the head gaskets again. When someone stole it out of his front yard and killed it that little V6 had 325,000 miles on it and still ran good.
Rene
My buddy had an 89 1/2 ton work truck with a 4.3 V-6 that lost the head gaskets. The fact it hydro-locked was what finally clued him in, and he found out it was hydro-locked after the starter broke. Rods and everything else were fine though, and it went another 60,000 miles before blowing the head gaskets again. When someone stole it out of his front yard and killed it that little V6 had 325,000 miles on it and still ran good.
Rene
I sure wish I hadn't deleted the pic of a 4.3 V/6 that hydro locked and made a connecting rod look like a pretzel just from trying to start the engine.
Being an automotive machinst for 22+ years I have probably seen many more failures than most people who don't do this for a living and just can't believe what a little water WILL do to an engine.
Being an automotive machinst for 22+ years I have probably seen many more failures than most people who don't do this for a living and just can't believe what a little water WILL do to an engine.
I guess there are plenty of variables, if the offending piston is nearer to TDC there has to be way less chance of bending the rod than if the piston is nearer the bottom of the hole.
Rene
Rene
You are absolutely correct.
Like I said in my first post, if the cylinder has "enough water" in it (more water than the combustion chamber can accept) then a bent rod, broken piston or blown cylinder wall are just about guaranteed everytime.
i'll throw .02 in here too..
As Scott has seen TONS of motors in his shop, I will guarantee I've seen WAY more water ingested motors than anyone in here... I probably get 25 a yr, no sh*t.. it's inherent in the marine biz, heck, I've done 6 repowers this commisioning season already due to ingestion (stuck valves, cylinder walls, etc) when your injecting seawater into the exhaust it's super common when exhaust parts fail...
anyway, having seen hundreds of water ingested mills over the last 10 to 15 yrs, I've had 2 bend rods... yup 2..... pretzeled the heck out of em, but only 2... in my experience, this is definitely a situation of circumstances... minor head gasket, or exhaust failure in boats, it ain't gonna happen usually... you'll get milkshake, possibly cylinder wall probs, stuck valves, etc, but generally it takes a catastrophic failure, good amount of fluid, to bend a rod... suck a couple gallons down the carb in a creek? sure, your more than likely gonna bend something...
btw, 95% of these are 350's, 454's and 502's... other car motors may vary i suppose due to con rod and cylinder design, etc...
As Scott has seen TONS of motors in his shop, I will guarantee I've seen WAY more water ingested motors than anyone in here... I probably get 25 a yr, no sh*t.. it's inherent in the marine biz, heck, I've done 6 repowers this commisioning season already due to ingestion (stuck valves, cylinder walls, etc) when your injecting seawater into the exhaust it's super common when exhaust parts fail...
anyway, having seen hundreds of water ingested mills over the last 10 to 15 yrs, I've had 2 bend rods... yup 2..... pretzeled the heck out of em, but only 2... in my experience, this is definitely a situation of circumstances... minor head gasket, or exhaust failure in boats, it ain't gonna happen usually... you'll get milkshake, possibly cylinder wall probs, stuck valves, etc, but generally it takes a catastrophic failure, good amount of fluid, to bend a rod... suck a couple gallons down the carb in a creek? sure, your more than likely gonna bend something...
btw, 95% of these are 350's, 454's and 502's... other car motors may vary i suppose due to con rod and cylinder design, etc...
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4xcrazy
3/4 ton status
I am personally not saying water in a cylinder cannot bend stuff up, i can absolutely see it happening to a running motor that gets a ton of water down the intake, i am just going off of what happened with my particular engine/headgasket failure that leads me to doubt the torque of a starter to bend the rods.
When i pulled out the plug to find out why my motor simply stopped turning over when i hit the key, a pretty good amount of water poured out of it, so i'm not exactly sure i guess just how much water it takes to do this kind of damage.
All i am aware of, is when i hit the key on my application, and situation, the motor rotated over to a point and just stopped, all i would get out of the starter is the click, no movement. Essentially starter and battery power was not enough to rotate it any longer. No major damage was done to my engine though.
POSSIBLY, the other cylinders did not fire before this piston hit it's stopping point, which may be the reason the rods bend in the first place, perhaps it's not the starter alone doing it, but the firing of other cylinders starting and assisting the starter...
again, i am not questioning the experiance of anybody on here, not arguing with your previous work history and experience, but there has to be other variables in this situation for everyone to have different results from a similar pattern of damage
something else to add, my engine, even this new one does not ever fire first thing in the morning, on the first hit if the key and with a single revolution of the motor, usually about 3-4 complete revs or so, i would guess, and it will fire up
When i pulled out the plug to find out why my motor simply stopped turning over when i hit the key, a pretty good amount of water poured out of it, so i'm not exactly sure i guess just how much water it takes to do this kind of damage.
All i am aware of, is when i hit the key on my application, and situation, the motor rotated over to a point and just stopped, all i would get out of the starter is the click, no movement. Essentially starter and battery power was not enough to rotate it any longer. No major damage was done to my engine though.
POSSIBLY, the other cylinders did not fire before this piston hit it's stopping point, which may be the reason the rods bend in the first place, perhaps it's not the starter alone doing it, but the firing of other cylinders starting and assisting the starter...
again, i am not questioning the experiance of anybody on here, not arguing with your previous work history and experience, but there has to be other variables in this situation for everyone to have different results from a similar pattern of damage
something else to add, my engine, even this new one does not ever fire first thing in the morning, on the first hit if the key and with a single revolution of the motor, usually about 3-4 complete revs or so, i would guess, and it will fire up
wasted wages
1 ton status
The tire guy in the truck shop drove our 2 month old chevy pick up
through a deep puddle in the road at about 55 mph...manual transmission..
It ingested so much water thru the intake,,,plus the inertia of the truck
kept the engine spinning until it hydrolocked and bent 2 rods into pretzels..
dropped the pan,,,pulled the drivers side head...blue wrenched out the 2 rods..
popped out the pistons..stuck new rods on....buttoned it back up....sold it quick !!
and yes.....I fired his dumb ass..
through a deep puddle in the road at about 55 mph...manual transmission..
It ingested so much water thru the intake,,,plus the inertia of the truck
kept the engine spinning until it hydrolocked and bent 2 rods into pretzels..
dropped the pan,,,pulled the drivers side head...blue wrenched out the 2 rods..
popped out the pistons..stuck new rods on....buttoned it back up....sold it quick !!
and yes.....I fired his dumb ass..
wasted wages
1 ton status
wrong.....
Water can actually be compressed. At a tremendous pressure of 1000 kg per square centimeter (which isn't strictly a pressure, but is listed that way in Smithsonian Physical Tables) water compresses by only 2.5% at 50 degrees C.
It maybe only 2.5%,,,,, but it can be compressed......
Got everything tore apart last night, minus taking off the head. Tried to pull the head off with my hands but won't budge. Found a small chunck of metal sitting in the lifter valley (about the size of a pea)..... so now I'm concerned. Hopefully it's a piece of casting or something. Will know more once I finally get the head pulled off. Any advice on how to get the head to break loose? I guess I should pull the oil pan as well. I got a bad feeling.........
Prybar under an edge to get it to break free...it's dowelled, so it's not gonna slide off or anything.
Rene
Rene
I'm assuming you have the intake manifold off (don't ask, i've seen the things some people do), and all 17 head bolts?
