TEST 4: Using A Chemical Block Tester (Combustion Leak Tester)

Blown Head Gasket Test (Suzuki 1.3L, 1.6L, 1.8L, 2.0L, 2.3L, 2.5L)

There are times when the vehicle does have a head gasket issue, a cracked block issue, or cracked cylinder head issue causing it to overheat that the 3 previous tests don't find. Is there something else that can be done? The answer is Yes! It involve doing a chemical block test.

The combustion leak tester (or block tester) test is used in all major/competent repair shops to confirm a blown head gasket issue.

This is how the test works:

  • A blue liquid chemical, which is blue in color, is placed in the tester (see photo above).
  • The tester assembly is then placed on the open radiator neck (you may have to drain some of the coolant in the radiator since this tool needs to 'gulp' some of the air inside the radiator).
  • The rubber bellow is then squeezed to suck in the air up through the two fluid-filled chambers. As the air bubbles up through the fluid, it will cause a chemical reaction.
  • If the blue chemical turns yellow (for gasoline engines), then combustion gases are entering the radiator. This result confirms a blown head gasket, a cracked block, or a cracked cylinder head issue.
  • If the blue chemical doesn't change color, then you can conclude that you don't have a blown head gasket, a cracked block, or a cracked cylinder head issue.

Where can you get the chemical and block tester? Here:

I want to thank Michael's feedback on this issue:

“I have a 2000 swift engine in a samurai, it has an overheating issue. It will force water out of the radiator. Only does this at high rpm such as driving on the highway at 65-70mph at 400oRPM. I have done all the normal testing that you have suggested in this article. I still had a exhaust gasses going into the cooling system. After I did your tests, I used a chemical block tester and found it to change colors. So I followed it up by Pressure testing the cooling system and removing the spark plugs. I let the pressure tester sit for 15min, then pressurized the system again for 15 more minutes. afterwards, I pull the fuse to the coils, and cranked the motor over I got moisture from cylinder 3. I after pulling the head, I found a crack between the exhaust valve and sparkplug. I think the pressure test and then check for moisture would also be a quick DIY way to test because now you can borrow a tester from most local auto parts stores like AutoZone. Thanks for the time and thank you for your article. It is both informative and basic very simple to understand. -Michael Z (10-23-2014)”

Frequently Asked Questions

1.)  How can I tell if the cylinder head is cracked?

The only way to know is to remove the cylinder head and visually inspect it. If the crack is wide enough, you'll be able to easily see it.

In many instances, a visual inspection won't be enough, you'll need to have the machine shop, that's gonna' resurface the cylinder head, for a pressure test.

2.)  Do I need to resurface the cylinder head?

The answer is YES! You should never reinstall the cylinder head or cylinder heads without first having an automotive machine shop resurface the cylinders heads (particularly over an overheating condition).

Now, of course, if you (or the machine) have checked it with a straight-edge and there's no warpage, then, and only then is the cylinder head not resurfaced.

3.)  I have a V6, do I need to remove both cylinder heads?

It's standard practice to remove them both and replace both cylinder head gaskets (and have both cylinder heads resurfaced).

This is important because the only way to make sure the other cylinder head isn't extremely warped or cracked is by removing it and and visually inspecting it and taking the necessary warp measurements with a straight edge and doing a pressure test.

Related Articles

You can find a complete list of Suzuki test articles here: Suzuki Index Of Articles.

Here's a list of articles, you'll find there:

Thank You For Your Donation

If this info really saved the day, buy me a beer!

buy me a beer

Suzuki Vehicles:

  • Aerio 2.0L, 2.3L
    • 2002, 2003, 2004, 2005
  • Esteem 1.6L, 1.8L
    • 1997, 1998, 1999, 2000, 2001, 2002
  • Forenza 2.0L
    • 2004, 2005
  • Samurai 1.3L
    • 1995

Suzuki Vehicles:

  • Sidekick 1.6L, 1.8L
    • 1995, 1996, 1997, 1998
  • Reno 2.0L
    • 2005
  • Swift 1.3L
    • 1997, 1998, 1999, 2000, 2001
  • Vitara 1.6L, 2.0L
    • 2000, 2001, 2002, 2003

Chevrolet Vehicles:

  • Metro 1.0L, 1.3L
    • 1998, 1999, 2000, 2001
  • Tracker 1.6L, 2.0L
    • 1998, 1999, 2000, 2001, 2002, 2003, 2004

Geo Vehicles:

  • Metro 1.0L, 1.3L
    • 1995, 1996, 1997
  • Tracker 1.6L
    • 1995, 1996, 1997