cylinder temperature sensors

[Richard_vmt]

I am interested in installing a cylinder temperature system. The type of sensor I see advertised goes under one spark plug in place of the crush washer. This seems to me like an invitation for an air leak at that point as the spark plug is changed--or else the sensor is an expensive replacement wear part. What is your experience with this type of sensor? Is there any other type of sensor which mounts permanently to some part of the head out of the way of spark plug changes?

[Mr_Diesel]

An EGT (Exhaust Gas Temperature) or otherwise called a Pyrometer is a very efficient way to determine the operating temperature of the engine.... A dangerous temperature for an engine with an aluminum head (vw engines) is between 850-900 degrees. These mount in the exhuast manifold and give you a really good idea of how hot the engine is running. The hotter the EGT, the hotter the engine is running. I've heard of these spark plug sensors, but cannot attest to their reliability... I fear the same as you do... Just adding a weak point to a crucial seal.

[Richard_vmt]

Mr Diesel, I am talking about aircooled which is about 325-350. I think we can both envision a situation where an air leak could create the temp rise it was detecting; great rip the sensor out and back to square one. That's what I want to avoid. But maybe those with actual experience know different, or these may be a different type of system. Thanks for responding though.

[Mr_Diesel]

Aha.... the air cooled variety.... An EGT will still work on the aircooled, but you'd need 2 to place in each manifold. I suppose the spark plug ones would work just fine.... Also, now I see why you'd want to know specific cyl temperature, because you don't have a cooling system with a common temperature sensor. I wish I could be of more help, man... Let us know what you find out.