Combustion Leak Tester and Head Gasket Test Kit
If you are trying to confirm a blown head gasket, a combustion leak tester gives you a fast yes-or-no answer by checking for exhaust gases in the cooling system. This page brings together the core buyer language buyers use in the UK: combustion leak tester, head gasket tester, block tester, block sniff tester, head gasket detector, and combustion leak detector.
LeakLogic currently offers one universal diagnostic kit designed for petrol, diesel, and LPG engines. It is built for DIY owners, pre-purchase inspections, and garages that want a practical block tester, head gasket leak detector, or head gasket sniff test kit without guesswork.
Current recommendation
For most UK buyers who want one combustion leak test kit that covers petrol, diesel, and LPG engines, the current LeakLogic Block-Check Blue kit is the right starting point. It includes the tester, fluid, tapered bung, and printed instructions, and it gives a clear blue-to-yellow result in around two minutes. If you searched for a head gasket tester kit, head gasket leak detector kit, or block tester, this is the page to start with.
LeakLogic combustion leak tester at a glance
| Best for | DIY diagnosis, pre-purchase checks, and workshop confirmation of suspected head gasket leaks |
|---|---|
| Engine types | Petrol, diesel, and LPG liquid-cooled engines |
| Typical result time | About 2 minutes once the engine is warm enough to circulate gases into the tester |
| What is included | Twin-chamber tester, Block-Check Blue fluid, tapered silicone bung, quick-start card, and full instruction manual |
| Manuals and support | Manuals and downloads, plus guidance on fitment, results, and common mistakes in the guide hub |
| Buy now | Product page with Amazon UK and eBay UK buying links |
Who this head gasket test kit is for
DIY owners
If you want to stop guessing whether coolant loss or overheating points to a blown head gasket, this is the quickest route to a usable answer without tearing the engine down first. It suits buyers looking for a head gasket detector or combustion leak tester they can use at home.
Used-car buyers
A block tester is useful before buying a car with overheating history, unexplained coolant loss, or suspicious mayonnaise under the oil cap. It also fits searches around vehicle inspection before buying when head gasket failure is one of the risks you want to rule out.
Garages and mobile mechanics
It helps confirm a diagnosis fast, explain the result to the customer clearly, and decide whether further tests or disassembly are justified.
How the test works
A combustion leak tester draws gases from the cooling system through a reactive test fluid. If combustion gases are present, the blue fluid moves toward green and then yellow. That is why this kind of block tester, cylinder head leak tester, or head gasket sniff test is so effective for confirming a blown head gasket or cracked cylinder head without stripping the engine.
How to read the result
A clear blue result usually means no combustion leak was detected. A strong yellow change means exhaust gases are getting into the cooling system. A weak or slow change needs careful interpretation and the right testing setup, especially if you are using the kit as a head gasket leak detector rather than as a quick yes-or-no screen.
Petrol, diesel and LPG compatibility
The current LeakLogic kit is designed for petrol, diesel, and LPG vehicles. What matters most is getting a proper seal at the filler neck or expansion tank and testing once the engine is warm enough to move gases through the system.
Fitment and bung guidance
The tapered silicone bung is built to fit a wide range of filler necks and expansion tanks. If your setup is awkward, read the manual before testing so you can position the tester without sucking coolant directly into the chambers.
Read the fitment and adapter guide or view manuals and setup notes.
Common mistakes with a block tester
- Testing too early before the engine is warm enough to move combustion gases into the cooling system
- Overfilling the tester with fluid so the chamber becomes messy and harder to read
- Allowing coolant to splash into the test fluid and distort the result
- Assuming a single cold-engine negative means the head gasket is definitely fine
- Ignoring fitment and seal issues that stop gases reaching the tester properly
Guides and support pages
How to test for a blown head gasket
A step-by-step guide to using a combustion leak tester safely and reading the outcome with confidence.
How a combustion leak tester works
Understand what the fluid reacts to, why the test matters, and where it fits in the diagnostic process.
Combustion leak test results explained
Know the difference between a clean negative, a strong positive, and a result that needs retesting.
Common block tester mistakes
Avoid the setup, seal, and fluid errors that make a good kit look unreliable.
Fitment and adapter guide
Get practical advice on filler neck sealing, awkward layouts, and why fitment matters for a usable result.
Manuals and quick-start guide
Download the PDF instructions, safety sheet, and get a quick reference checklist before you test.
Ready to buy?
If you are looking for a combustion leak test kit, head gasket tester kit, or head gasket detector you can use on petrol, diesel, or LPG engines, start with the LeakLogic Block-Check Blue product page. From there you can buy through Amazon UK or eBay UK and still come back here for manuals, testing help, and result interpretation.