4 Engine Block Repair Tips

Engine block repair can be a tricky, often costly business. A cracked engine block can be fixed rather than replaced. It’s something you can do yourself if you have the skill and the knowledge; engine block repair certainly isn’t for novice mechanics. There are things worth knowing about the different repair methods that can help you, and also warn you about how well they might or might not work.


Many people do use epoxy for engine block repair without any problem. You need to be aware that there are limits on its usefulness. For a successful engine block repair the crack can’t be too big, and you’ll need to have an epoxy that’s able to withstand high temperatures. Check this first, because not all of them can do so. Also, allow a full 24 hours for the epoxy to cure in the engine block before you start the motor. Use a proper metal epoxy.


Surprisingly, welding is the most complex and least desirable option for engine block repair. Don’t assume it’s the obvious way to cure a cracked engine block. The welding process here is delicate and time-consuming, something that needs to be done by an experienced professional.

Filling the crack with a weld is difficult enough, especially as it can be quite tricky to reach. The other big factor is that the metal needs to be exceptionally hot, around 1000 degrees Fahrenheit. That’s before you start welding. In other words, welding as an engine block repair should be your last resort, and you should know that the welds often fail later.


The vast majority of people will use sealant for an engine block repair. If there’s a crack, the sealant will fill it, and can save you money on replacing the block, or so they tell you. It can often work. You need to be sure you follow the instructions exactly in order for it to be effective. Most sealants require that you empty your radiator before adding the sealant. Once you’ve done that, you’ll have to switch on the engine and let it run for a certain period.

The problem is that you won’t know if it’s really worked until later. After you turn your engine off again, you’ll still need to drain the sealant from the radiator and refill with fresh coolant.


Replacing your engine block is an engine block repair, especially if you do it yourself. If the crack is extremely bad, or the other solutions didn’t work, it might be the only option left to you.

You can try to rebuild the block, but for what you’d invest in money and time, you might as well replace it. That will only be worthwhile is your vehicle has plenty of life left in it. If not, the sensible and economical choice is just to scrap it and buy a new vehicle. That might seem extreme, but it can end up being the obvious things, depending on how you weight the pros and cons.