rusefi.com

When identifying a head gasket issue and isolating if a gas in the radiator is air pulled in from the air pump or pulled in when engine is cooling, vs combustion gasses, one would commonly use a tool like this https://www.google.com/shopping/product/13190523127613337511?biw=1280&bih=642&q=combustion+gas+tester&bav=on.2,or.&bvm=bv.87611401,d.eXY&ion=1&espv=2&tch=1&ech=1&psi=B2z9VIubBIurNqasgIAG.1425894406446.17&prds=paur:ClkAsKraX81q96W34Wq4yFrEP84N-nFyAwMeUzDfG8oBJr0L62fKfCawx-L2atxFikv97oIEZjUWIs3Cp-xdOjQj8LIPm0oIL-CRFaJyITomCq_90QcJGiGv0RIZAFPVH719FDm9qflouEOpLThYq0rFacJdJA&ei=sG79VNDhG4fegwSHq4DYDQ&ved=0CHQQpiswAA

While that is good for a low cost shop use situations, the chemicals are kind of a blah to deal with. Who knows how to dispose of them or if they are carcinogens? Do the chemicals go stale over time? What happens if the fluid freezes? ect. So I looked for some electronic versions of a combustion sensor, and found a price range that's commonly between a couple hundred dollars, to thousands of dollars. Such an option would be handy for shop use, but I wonder, what happens when people use those liquid head gasket repairs, which may patch a combustion breach for a period of time. It would be handy to have something I can install in the vehicle for a prolonged period of time and sense an intermittent combustion to radiator leak.

I found this ITEAD sensor, and I'm tempted to find a way to add this sensor to the vent line on the radiator in a used vehicle I own. ftp://imall.iteadstudio.com/Electronic_Brick/IM120710024/DS_IM120710024.pdf

The used vehicle I have may or may not have had some liquid head gasket repair added to the coolant. I know it has intermittent overheating issues. I think this kind of tool would allow me to isolate the problem. Does anyone have any thoughts about if such a sensor could play nice or be of any use in this kind of detection?

Do you have the tools to perform a leak-down test?

If so, pressurizing the cylinders while monitoring the pressure in the cooling system will let you know right quick if the head gasket, cracked head or cracked block are an issue.

Hmmm, good point.

I have compression test tools, and I should be able to modify them to do a leak down test. I'll have to get something to measure the radiator pressure. I seem to recall you can get a replacement plug thing for the rad cap which can allow a standard hose fitting.

Oh the joys of crappy vehicles.

No real need to measure the pressure building up, just knowing there's a leak is enough to tell you there's a problem.

If you apply pressure to a cylinder, the cooling system is full, and you get bubbles in the radiator, you have a problem.