How to fix coolant leaking from engine block without tools k-seal

In this post, we will show you how to repair coolant leaking from an engine block or radiator quickly and fast without tools. This is the trick many mechanics don’t want to tell you about and should only take you about 15 minutes.

If you have the following symptoms in your car you could have a leaking engine block or radiator.

Coolant leak symptoms

Coolant leak symptoms overheating
  • Overheating.
  • Steam from the engine bay.
  • Sweet coolant smell inside the car.
  • Coolant drips onto the floor when the engine is off.
  • Pink or green stains inside the engine bay.
  • Wet engine noise and heat protector.
  • Low overflow level tank.
  • Bubbling in the overflow tank.
  • Adding coolant to the radiator every week.
  • Missfire on startup and running rough.
  • Steam from the exhaust pipe.
  • Blocked radiator overflow hose pipe.
  • Coolant leaking from the bottom of the car.
  • Car leaking antifreeze when parked

The above faults can be coolant or head gasket leak symptoms.

Coolant leak repair cost

Now I used to work in a small mechanics car repair shop and we had standard prices for repairing head gaskets and faulty radiators. As a mechanic, I would be billed out at $80 an hour plus parts which also had a small markup of around 10% to 20%

So for a radiator repair depending on the size of the car and radiator, it would cost around $500 to $800 to replace.

Head gasket repair cost.

Repairing a leaking head gasket on a car is going to cost between $1000 and $2500 depending on the size of the engine. There are many hours of work to replace a simple head gasket. New spark plugs, timing belts, and head machining are a few jobs that may increase the price. But the majority of the cost will go into labor.

Often it will be cheaper to get a reconditioned engine than repair a head gasket.

How to fix a blown head gasket without replacing it

How to fix a blown head gasket without replacing it

A product called K-Seal Ultimate has been scientifically tested to fix a blown head gasket without replacing it. It is a simple shake-and-pour solution that can repair your engine leak in minutes. K-Seal is the only coolant leak repair fluid carried by the AA, the UK’s largest roadside repair company.

Many repair shops in America and Australia carry K-Seal as a cheap solution to fix coolant leaks. I love that it can be left in the car coolant to continue to plug leaks as they happen.

My old Ford Focus 2003 model had developed a small misfire on startup and was slowly consuming coolant. This is a sign that I have an internal coolant leak in the engine. The car is not worth very much so it is not worth replacing the head gasket.

There were no signs of a coolant leak from the bottom of the car so it must have been leaking into the engine through a blown head gasket.

So it was off to the local auto shop to find some K-Seal. They only had the Original K-Seal, not the K-Seal Ultimate so I thought I would try that first.

K-Seal Instructions

K-Seal Instructions How to fix coolant leaking from engine block

The most important thing to do is shake the K-Seel bottle fast and hard for 30 seconds. This gets all of the ingredients such as the separated ceramic microfibres and copper particles blended together.

The Ford Focus only has an overflow tank so I poured the whole bottle of K-Seal into the overflow tank. This then flowed into the radiator as the level was low.

I then topped up the overflow tank with red pre-mix coolant antifreeze, tightened the cap, and started the car.

The instructions say to idle the car up to operating temperatures which took a few minutes. I then let the car idle for another 5 minutes to transfer the solution around the engine block.

I then turned the car off and let it cool down for a few hours. Once it was restarted I noticed that there was no misfire and it started running smoothly again. It has now been over 4 months and the coolant level has not reduced and there are no more leaks around the engine bay.

You can add KSeal to a hot engine but be careful of pressure in the radiator when removing the radiator cap. Hot steam and liquid can come out and burn you. It is best to let the car’s engine cool down first.

“The test data shows that K-Seal is capable of sealing 0.635mm diameter holes and 0.254mm wide by 12.7mm long slots satisfactorily in accordance with ASTM D3147.”


Radiator cores are larger than 0,63mm so that is why K-Seal does not block up your radiator and is safe to use on all cars and motorbikes. It is safe for all types of radiators even copper and aluminum ones.

Guarantee to work

K-Seal is so confident that it will fix your head gasket failure, cracked block, or porous block that you can claim a full refund or a replacement bottle. You can find details on how to claim here.

Take my word, it fixed my coolant leaking from the engine block. It was only 5 minutes of my time and was so simple. Shake and pour.

Radiator coolant leak repair

car leaking antifreeze when parked

K-Seal is perfect for radiator coolant leaks. These are easier to diagnose as you can quickly locate the leak in the front of the car.

Start with a cool engine and slowly remove the radiator cap. Be careful of any hot fluid in the radiator. Shake the K-Seal bottle well for 30 seconds and pour into the radiator. Start the can and idle up to operating temperatures.

Run the engine for a further 5 minutes to cycle the coolant around the radiator and the engine. This will begin to plug any holes in the radiator. Turn off the engine and allow it to cool down fully.

Coolant pouring out of the bottom of the car

If radiator coolant is pouring out of the bottom of the car you may have a hole in a coolant pipe or the pipe has come off. Waite for the engine to cool down before trying to replace the faulty pipe.

K-Seal won’t repair a crack or hole in a radiator hose as these are often too large for the liquid to plug up.

Plastic radiator connection points can fail over time and this will require a new radiator. So if your car is leaking antifreeze when parked then try K-Seal first.


If you want a cheap easy solution on how to fix coolant leaking from the engine block then try K-Seal. I can recommend it as it worked for me. It has saved me over $1000 from a head gasket repair job.

It has now been over 4 months and the Ford Focus engine leak has gone. No more having to top up the radiator bottle every week and having a misfire.

Read more about how I repaired my Ford Focus rough idle with no check engine light fix.

K-Seal will work on cars, motorcycles, jet-skis, ATVs, and any motor with coolant flowing through a radiator. I’m a fan.

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