Saved a blown head gasket job with a $30 coolant test kit in Omaha

Last month a fleet truck came in with white smoke and a mystery overheating issue. I was ready to tear down the heads, but my coworker said to check the coolant for exhaust gas first with one of those cheap block test kits. Sure enough, the chemical turned yellow and confirmed a small leak in the oil cooler instead of the gasket. Swapped the cooler in 4 hours and saved the customer close to $1,800 in labor. Has anyone else caught a false head gasket diagnosis with a simple test first?

2 comments

2 Comments

dakota4151mo ago

Yeah that test kit is solid but the color change is more about combustion gases in the coolant, not just any leak. A bad oil cooler can let oil into the coolant and that'll mess with the test too. So it's less about catching a false gasket diagnosis and more about knowing what the test actually shows you before you trust it.

lewis.terry1mo ago

That test kit's saved my butt more times than I can count, better than cracking open a clean engine.