Do I need to replace head gasket or engine?
 

Since I am still in panic mode with my mind racing all over the place I figured I should ask my corvette brethren to share what they think. The lower radiator hose popped off yesterday. I pumped all the coolant out and had no idea. The temp gauge didn't show a higher than normal reading. In high sight maybe because there was no water left in the engine to read. I put the hose back on and filled it back up with antifreeze. Check the oil and it was low but looked dark and not milky.

So long story short a few hours later when I was going to leave it would not start. Heck after trying to pop the clutch thinking the start went I discovered the engine is seized. Also noticed at this point the new anti freeze I put in migrated to the oil pan as the oil leave had rose a lot on the dip stick.
I hope to spend my Labor day there with some tools tinkering. I will pull the plugs to see if a cylinder is full of water. Maybe this would explain being hydro locked?? Maybe drain the oil to confirm that filled with coolant.

So my question is given this limited info do you think I need a new head gasket or did I crack the block? I never had a cracked block before so I am not sure how to tell.

Is there anyway for coolant to get into the oil besides bad head gasket or crack?

If its just that I over headed it and and need to replace the head gasket I am OK as I have no problem doing that myself. If it is more than that I really don't know what to do at this point. Pull the engine and replace it. If it's cracked I don't think it would be rebuildable. Darn crate engines are pricey and it's been years since I have built an engine. Not to mention I no longer have the cherry picker( engine puller) but I do have a bad back UGH!

Coolant can enter the oil pan via a failed Intake gasket at the water ports. Rare, but happens.

Before wrenching on this thing, run a Compression Test or Leak-down Test unless the pan is truly full of coolant.
Another option in your case, with a specialty tool a radiator pressure tester at the radiator neck. If the cooling system will not hold air, where is it going?

And from what I remember, more blocks are cracked from freezing than overheating.

You said it's seized, and you're thinking head gasket?

I'm thinking rebuild, and the machine shop will tell you what's salvageable or not.

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superdave - Step 1 - Pull the plugs - and with all the plugs out - try to crank the motor over - if it spins over - plan to pull the heads.

Let us know what happens...

You said it's seized, and you're thinking head gasket?

Yup, My head is spinning right now but think maybe it's seized because the cylinder is full of antifreeze. I can't help but wonder if the cylinder filled up because of a blown head gasket. I'll know better once I pull the sparkplugs.
Sadly what the local machine shops & engine builders around here charge it is cheaper to buy a crate motor. I was shocked when I priced rebuilding my Tahoe engine vs GM crate engine. Crate motor was cheaper.

superdave - Step 1 - Pull the plugs - and with all the plugs out - try to crank the motor over - if it spins over - plan to pull the heads.

Thanks that is actually my plan. If it's not raining I will give that a try on Monday.

At this point you are missing some coolant.
Oil looked dark but not milkshake.
Will not crank. Coolant in cylinder or
starter solenoid "fried" due to overheating?

A blown head-gasket 99% of the time will be seen in the rearview mirror. (and the burnt sweet odor)

If the cylinders are truly full of coolant, use caution when cranking. Even with the plugs out, you could bend rods.

Will not crank. Coolant in cylinder or
starter solenoid "fried" due to overheating?

A blown head-gasket 99% of the time will be seen in the rearview mirror. (and the burnt sweet odor)


One of my first thoughts was the solenoid was bad. When we were testing the battery I tried to crank it and we noticed some smoke coming off of it. Later I though sure it smoked because the engine is ceased. Man I hope it's not seized and cracked. I did not think this may have happened to the starter due to the heat issue. Thats a positive thought.

I only noticed the cloud that looked like the old mosquito control truck when I pulled on to the street at my buddy's shop. Never saw it on the high way. I really thought it popped off just before I arrived.
I did restart it after I arrived as I filled the radiator back up and watched the level in the radiator. So once it didn't crank when I went to leave was a big surprise.

it is siezed cuz it is hydrolocked. you COULD have pumped coolant past the rings trying to force it to turn over. at this point, drain oil. put 2 quarts back in. that is enough for oil pick up to pick up oil. pull the plugs. have somebody crank engine while you are watching to see which side and cyls blow like moby dick. as headsup said, blocks crack from freezing. heads can crack from heat. but they will blow a little bit of steam. not volume water. it is the head gasket or intake gasket. get a cooling system pressure tester. hook it up and pressurize. it won't hold. get a piece of garden hose about 4 feet long. makes a good stethoscope. listen in each plug hole and see if you can hear the air hissing. open carb butterflies and see if you can hear air there. take intake off carefully you will be looking for gasket damaged by the cyl you saw coolant blow out the plug hole. if that gasket looks good, pull that head. again carefully. this is an autopsy, not just disassembly. you will see something. you can't get volume coolant leaking without being able to see the leak. post pics of gaskets and head and block surface. pull the other head too. if one got bad enough to blow, the other is close. if you do not see any damage in either gasket, check the cyl the water blew out. piston all the way down and check the walls for a crack. also unlikely to flow enough coolant to fill a cyl while not running. well, this is enough to get you started.

Thanks Derekderk Your reply made feel a bit better. If I cracked a head I am OK with that. Sounds like a good time to upgrade to an aftermarket heads. I have fulie heads on it now.
I also just ordered a new High torque mini started. The same one that I put on my 1979 vette. It fixed my starting issue on that car.

Keep us posted on what you find.

Just a heads up, if you try to crank it with a hydro locked cylinder a starter can bend rods much easier than you would think.
Beware. :ack:

Sorry to say this but its going to cost you about the same to rebuild it as it would to get a long block crate motor if you arent luck enough to have not done any damage when you tried to crank it over.

How many miles are on it and did it have any kind of performance behind it? If its just a regular old motor with no great power behind it, roll the dice and just regasket it, you can ball hone it, rering it and maybe through some new heads on it and see if it keeps the fluids where they belong. If it doesn't, you can still use those heads on the rebuild or the short block and only be out a couple hundred on gaskets and rings. But the price will be about the same with any serious machine shop work including crank work and a full balance vs a short block crate motor. But at this point you can add some compression and get a 375hp to 450hp motor and be done with it. Just get the new heads with that next step in mind. Maybe a lower head volume like 58 to 62 cc and a flow around 185. That would work out nicely for a good street build

Thanks Rescue Rogers It's a low mileage engine. It was professionally built and installed before I bought it. It was built awhile ago but very low mileage since I don't drive the car very often. It came with a gear drive installed. I'm not sure how I felt about the little whine noise it makes.
I hope to drain the oil, remove the plugs and see if it will turn over later this morning.
I hope once I get it home( won't be soon ) I can remove the head that I believe I should see what cylinder blows out water today and inspect the gasket and head for cracks. Maybe I can get away with new head gasket or new heads.
I appreciate all the replies and they have helped me. Of course now I am concerned that I could of damaged a rod. Never would of thought about that without you guys.

You didn’t. I had a boat. A few actually. But one, rain water on back seat-engine cover dripped on intake and gasket leak let it fill 1 cyl. I would crank until it hit the water then cycle key a few times to push water past rings. Boat started and engine heat boiled out the water. One time engine got cranking up to full speed and then it hit the water. SLAM! Then I started it and heard engine knock. I put an S bend in 1 rod so bottom of piston hit crank throw. You did not hurt the engine unless it was really spinning when it hit the hydro lock. Not saying engine not hurt. But you didn’t make it worse tryna crank it.

Thanks Derekderek, I was concerned since we were pushing it and tried to pop the clutch but for now I am focusing on that I only need to freshen up the top end. Honestly I am OK if that all I have to do. Thats just some time and money. Changing the block is nothing but lots of money and hard work. Since the weather will soon be cooler I can do the top end in my driveway.

Once heads are off, measure how far down in hole pistons are at tdc. Check all 8. If none diff more than a few thousandths, you are ok there.

A little update and a question.
I pulled the sparkplugs and turned it over. Great sign to me. So it was only hydro-locked as thought. Water poured out once I removed plug #4. Bumped it 3 times. No water came out on the 3rd and last time.

The shop owner painted a picture of doom and gloom to me. He said since the antifreeze got mixed in the water all the bearings will now be corroded or compromised from it. He said don't waste your time trying to do the top end, pull the engine and fix it( including cam bearings etc.). I don't believe he was trying to drum up business for himself but honestly believes it. BTW he runs a very impressive restoration shop. He deals with 6 figure cars and only is letting me play at his shop as a favor to a mutual friend. He is building a 54 retro mod vette right now. New frame LS engine original looking body. Neat car but so is the Super Bee, 57 T-Bird, numerous Camaro convertibles in his shop.

So my question is while I do not disagree that anti-freeze is corrosive to engine bearings, would you be concerned at this point? I am telling myself not to worry about it and remove the heads and inspect the gasket, the heads and inside of the cylinders. Reassemble with the heads or rebuild or replace the heads.
Does this sound reasonable?

He ain’t liein. Antifreeze is really hard on bearings. If I were you, this is what I would do.
Pull the heads, replace head gaskets. Check heads for warpage, if none, check for any pistons lower than others that would indicate a bent rod. If none, put it together and run it. It’s a crap shoot but at that point you have only a small amount of money spent. JMHO

YOu said you added antifreeze and it went straight to the pan. But you didnt get the motor running again at that point or did you? IF not then the antifreeze couldnt have gotten to the bearings. If you did and milkshaked the engine replace the bearings. ITs easy and its a couple hundred bucks. IF you havent done cam bearings they are in the box the order they go in, dont mix them up or have a shop do them