Over the years we have had an opportunity to inspect and diagnose many, many vehicles that were suspected of having cylinder head gasket issues. When “traditional” methods did not reveal an issue, alternative diagnostic techniques were used in order to try and isolate the problem. One such method was the use of a five gas analyzer. A gas analyzer is a wonderful tool, but sometimes it is not the best tool for finding cylinder head gasket problems that might be in the “early” stages of failure. We have had instances where exhaust gases were present in a cooling system, but not detected by a five gas analyzer. These exhaust gases were actually “picked up” by a tool that looks at only one gas instead of multiple gases.
Dilution can also be a big factor. A five gas analyzer is looking at five different gases, while a tool that may look at hydrocarbons, carbon monoxide or carbon dioxide individually would have a better chance at detecting one of the exhaust gases that would be present if for example a cylinder head gasket failed.