# water drain plug on cylinder block



## BwhiteH (May 20, 2011)

Hello I need help figuring out the thread size of the water drain plug on cylinder block for the versa with the hr16de engine. I want to install a glowshift electric water temp gauge on my car I know that the dash light should be enough but I've heard so many horror stories that I won't take a chance; so I need an adapter from the 1/8 NPT which is the size of the electric temperature sender to whatever size the water drain plug is.

If anyone sees this a potential problem or can help me with the plug size will be greatly appreciated.

I'll post pictures of the setup once I finish, I have already done all the wiring, also I bought a single gauge pod, heated it up to mold it to my A pillar and use some fake leather so it will look almost stock.


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## rogoman (Dec 16, 2004)

The water drain plug should have a JIS PT 1/8" thread. BSPT 1/8" and JIS PT 1/8" have same thread spec as listed in ISO 7-1.

Look for a 1/8" BSPT to 1/8" NPT adapter to hook up the temperature sender.

1/8" BSPT is very similar to 1/8" NPT, but the thread pitch is different (1/8" BSPT is 1/8"-28, 1/8" NPT is 1/8"-27). You can get BSPT adapters from McMaster-Carr ( McMaster-Carr ).


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## BwhiteH (May 20, 2011)

Are you sure it seems the plug seems wider and has a lot less threads. It looked more like a 1/4NPT. It's the one for the coolant drain on the engine block not for the oil.


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## rogoman (Dec 16, 2004)

You'll have to remove the drain plug and match it up for width with the sending unit. If the width is the same, you'll be able to screw the sending unit in about maybe one thread but that's all because the thread pitch is different.


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## Ken B (Aug 7, 2017)

Get yourself a thread pitch gauge. They come in handy and don't cost much.


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