Jump to content
SAU Community
  • Welcome to SAU Community

    Welcome to SAU Community, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information for you to signup. Be apart of SAU Community by signing in or creating an account.

    • Start new topics and reply to others
    • Subscribe to topics and forums to get email updates
    • Get your own profile page, build reputation and make new friends
    • Send personal messages to other members.
    • See fewer ads!

    Consider joining our newsletter for the latest content updates

    Click here to register


R34 Series II lower radiator thermo switch thread size

Recommended Posts

Disclaimer: This isn't a topic specifically related to forced induction, though the vehicle it applies to will be boosted, so...


I recently purchased a Series II R34 GTR radiator from Koyorad to install in my ENR34 project. I'm building a motorsport-level (or near enough, anyway) harness for it, so the addition of a threaded boss on the radiator to use for a coolant pressure sensor was enticing. Especially since I was buying a radiator, anyway. I have a large M16x1.5 bolt that I've easily threaded into the hole, but it still has a little play at full engagement. Does anyone know what the true thread size of this hole is so that I can buy an adapter for a pressure sensor?



Link to post
Share on other sites
Posted (edited)

If M16 is close, then possibly 3/8 BSP or BSPT. Or its simply a M16 tapered thread. Buy a set of thread gauges they are cheap and last a lifetime or two. My set belonged to my father.


Adapters you can get from


Edited by Rusty Nuts
additional information
Link to post
Share on other sites

I had the absurd idea of actually contacting the manufacturer through their "Contact Us" portion of their webpage and they insist that it's an M16x1.5 thread. I assume that once the o-ring on the bottom of the hex portion of the sensor its in that slight recess, combined with light torque would eliminate the play I'm feeling now.


Anyway, just updating this in case anyone searches this topic at some point in the future.

  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...