Sniper EFI Coolant temperature sensor ½” NPT version of Holley 543-120

Now available to ship! Also ask about ¼ NPT and Aluminum housing versions.

Many intake manifolds have a ½” NPT position available for a coolant temperature sensor but Holley only offers a 3/8” NPT sensor. If you need a ½ inch version, they suggest using 3/8” and a bushing. The problem with using a bushing is these are tapered thread and a smaller size NPT simple does not thread far enough to eliminate the inevitable air pocket. Air pockets can cause localized boiling which lead to inconsistent sensor readings which are not representative of the actual coolant liquid temperature; instead elevated due to local boiling.

I have Sniper systems for two vehicles and after being unable to find a commercial solution I decided to create the proper part. This is NOT a Holley branded part. I have created a ½” NPT version with a custom machined solid brass housing, the original style electrical connector and a sensing element which matches the Holley branded PN 543-120. Simply said this is a drop-in replacement for the Holley temperature sensor but with ½” NPT.

Sensors are hand assembled in the USA with, some parts sourced outside the US. The sensing element itself is tightly controlled to +/-1%. It’s common for temperature sensors to be +/-3 to 5%. The sensing element is surrounded by a highly thermally conductive paste to ensure minimum temperature change lag time. An o-ring is built into the assembly and the brass housing is clinched around the electrical connector.

-Brass housing – Made in the USA (Wisconsin)

-Electrical connector and sensing element – Foreign made

All sensors are tested prior to shipping.

For ¼ NPT I do have a couple of parts I made with AA6061 Aluminum housings in the event someone wanted better compatibility with an Aluminum block, head or intake. If you want the Aluminum version please ask. I can make ½ NPT in Aluminum but I would need to get housings.