[kmyers1643]

Looking for some suggestions here. I recently broke my OEM thermostat housing and replaced it with this one.

Thermostat Housing Coolant Neck Billet 280Z 280ZX

New billet aluminum water outlet thermostat housing for Datsun 280Z and 280ZX with 3 bolt neck. These are stock replacement parts so they will work along with your OEM components. The 3-bolt water outlet has been discontinued for years so now we have a replacement. Billet milled finish...

zcardepot.com

The Thermotime sensor, and temp gauge sending sensor both seated into the holes fine. My temperature switch sensor however fit very loose in the threads. It would wiggle in the threads a lot if it weren't fully tightened. I snugged it down a bit with some thread locker and hoped it wouldn't leak but it is dripping. I don't know what the thread sizes are on these sensors but the housing says 1/4" NPT and claimed to be the same as OEM. The threads on the original thermostat housing are correct and fit tighter and I have checked to make sure the old original sensor and the new sensor were the same and they were.

This is the sensor in question.

Coolant Sensor Temperature Switch 280Z

Water Temp Sensor Temperature Switch 280Z - 800-035 (). New engine water temperature sensor switch for Datsun 280Z 1975 1976 1977 1978.

zcardepot.com

Anyone know of a thread adapter or similar sensor with the correct threads?

 

[pilgrim]

Try some teflon tape used in plumbing. perhaps an extra wrap or two.

 

[Dave Datsun Tech.]

That sensor is not NPT pipe thread. It seals on the washer. Maybe ask them if they have one that fits.

 

[bruce83na]

I see that lower housing has 5 threaded holes in it
(1) 3/8" NPT (pipe thread)
(2) 1/4" NPT (pipe thread)
(1) M14 X 1.5
(1) M16 X 1.5
I have 2 quesses: You're either puting the temperature switch sensor into the wrong hole, or the hole for it was tapped the wrong size. Here's an image where everything goes.

 

[bruce83na]

Here's a different layout of a stock housing

 

[heybuddy]

KMyers, you ever find the correct fitting? I'm having the same problem. 3 of the sensors fit, (but in different locations than original), Smaller sensor with seal ring does not fit into the remaining 3/8 NPT hole. I had a local hydraulic shop drill out an adapter but then you have to use a second adaptor so it s a bit ridiculous looking.