Block-Check Blue™ Diagnostic Test Kit
The definitive DIY test for diagnosing a blown head gasket. Get a clear, yes/no result in under two minutes. The kit includes our UK‑made non‑toxic Block‑Check Blue™ test fluid, twin‑chamber tester, tapered silicone bung (fits most petrol, diesel and LPG cooling systems), a printed quick‑start guide and a full instruction manual with safety notes and troubleshooting tips.
- ✅ Universal fit for petrol, diesel & LPG engines
- ✅ Safe, non-toxic, UK-made formula
- ✅ Includes everything needed for ≈ 15 tests
- ✅ Full instruction manual + printed quick‑start guide
- ✅ Fast UK shipping with Royal Mail 1st/2nd Class options
How it works
1) Draw gases through fluid
Insert the tester into the expansion tank and let the engine idle. Exhaust gases (if present) bubble through the blue fluid.
2) Watch the colour
Blue stays blue = no leak. Blue turning green/yellow = combustion gases detected.
3) Decide with confidence
Get a definitive yes/no in under 2 minutes so you can repair, negotiate, or rule out a head gasket issue.
What Our Customers Say
"Worked perfectly on my Ford Focus. The fluid turned yellow in about 30 seconds and confirmed my suspicions. Saved me a fortune on a garage diagnosis. Highly recommended!"
"Brilliant bit of kit. The instructions were clear and the test was easy to do. Thankfully my fluid stayed blue, so my issue was just a faulty thermostat. This tool gave me total peace of mind."
"Does exactly what it says on the tin. Quick and easy to use. It's great value for the price."