Engine block has a hole, should I replace engine block or engine assembly?

I forgot to leave the water in the cooling system and the worst thing happened when temperature dropped below 19. The engine block is cracked and there’s even a hole on the engine block!

I wonder if changing the block or the whole engine assembly is time-and-cost-wise as I’m not sure the engine is still in good condition. The car now only starts for a few second, the head gasket is fine.

Forgot to leave water in cooling system. Don’t you mean you forgot to drain water out? And if you had a proper antifreeze mix you would have to have done nothing. Start looking for a used engine , this one is done for.

At any rate, you don’t just replace the block. Your options are a short block which is the pistons, crank, etc.-everything below the heads. A long block is the short block plus the heads and maybe intake manifold depending. Then they swap the bolt on items from your engine like starter, alternator, etc. In your case it sounds like you have substantial damage that may well include the heads. I would suggest the long block or a used engine. less chance of problems that way.

Not knowing the make/model/year, only a guess that it will cost around $3500 to $5000 for a replacement engine. Whether that makes $$$-sense depends on how much you like the car and whatever other problems it may or may not have. Lots of people replace the car’s engines when the run into problems like this. There’s junkyards full of used engines where the only problem was the car got into a fender bender and was totaled, written off by the insurance company, but the engine remained undamaged & is still in great condition.


Used engines are available for older cars, buying a new or remanufactured short block may cost more than you want to spend. With a used engine you usually have to accept the complete engine, they won’t sell just the block.

I wonder if the car is still reliable after the engine swap. Theoretically, I don’t see any harm if it is done by a certified mechanic, it is also better if the engine is newer. Am I wrong here?

It’s a 2009 Honda Accord 3.5

Don’t bother trying to overhaul the broken block.

Just for the heck of it, you might try cleaning the area and pack it full of JB Weld.

About 25 years ago a good friend of mine bought a '53 GMC pickup out of a farmer’s field. It had the 6 cylinder with a 4" crack in the side of the block due to sitting for so many years with water in it and which froze it.

He used JB Weld and drove that truck for another 6 or 7 years with no problem.

That engine uses a timing belt

When you locate a used engine, I STRONGLY urge you to replace the timing belt, tensioner and idler before installation


Wow, that sounds amazing! Did your engine have a hole, mine is as big as a little finger with some cracks. I’m thinking of using the metal pieces to either seal it with JB Weld or take it to a welding shop.

Others may disagree but if you put in a used engine, I would really try to find a 2009 match to avoid any computer/sensor/compatibility issues. It may be the same engine from year to year but the electronics may not be compatible with what you have. I’ll defer to the mechanics here on it. Lower mileage yeah, but you still won’t know what kind of service it had in its life.

Thank you! I forget the compatibility issue since there’s a chance the computer may not accept the electrical components of the same engine from other car. It turns out to be more complicated than I expected by just simply swapping it.

This car is 9 years old…you could find a good used car for less than what it will cost you to replace that engine.

Absolutely true. But a V6 Accord is a pretty sweet ride, IMO, so it might be worth saving.

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Well, yeah, if you buy new. Get a junkyard motor.

The OP needs to clarify this statement. If the cooling system was actually empty it would not have frozen. Did someone give the OP bad advice about having antifreeze in the cooling system.

I think this is the vehicle that shakes at 120 MPH and he said he took it to a track for drifting ( front wheel cars don’t drift well ) . Apparently this thing has had rough treatment so replacing vehicle might be a better step.

Could that hole possible be a freeze plug?


For a car of that age, I assume you’ll be looking for a used engine. It might be reliable or it might not, depending on how it was maintained. That’s the chance you take with a used engine.

Why did you have only water in the engine (assuming that’s what you meant)? That’s bad for the cooling system, regardless of the temperature.

That depends on the mileage, and overall maintenance of the rest of the vehicle.
It also depends highly on you. If you do things like use water in the cooling system rather than proper coolant, the car will not be reliable. If you’d used the proper coolant mix to begin with, the engine you now need to replace (it’s history now) might have been reliable.

Never hesitate to post questions here if you’re uncertain what to do. I’d rather help someone learn how to properly maintain a vehicle than discuss an engine replacement with him/her.

getting some basic inspection on the used engine beforehand can be a good indication on if it will work reliably or not

I would inspect what can be seen from oil filler and oil gauge for obvious coked oil deposits, then spark plugs for obvious oil deposits and sooth problems, would definitely disqualify any used engine showing issues there

it is still a lottery, but having some basics inspected makes chances for winning much higher

Can you post a picture of the hole in your block?

for some reason, I have a feeling that this isn’t what we think it is…