Coolant gauge sensor

[3tc power]

I have a question about the coolant sensor. If you look at the picture is the sensor supposed to be like this
With a space? Or do these have crush washer? I been looking through my stash
Of sensors and they all do the same thing. Any info will be great guys.

 

[3tc power]

This is the same kind of sensor I have in the water neck...

 

[hvyman]

Its npt or bspt threads.

 

[3tc power]

i'm not sure bro!

 

[hvyman]

It doesnt take washer and most likely wontw in flat.

 

[3tc power]

ok cool! i never looked at this sensor installed before or never payed any attention. but when i first seen it like this i was like WTF why isn't it going all the way in. it did that with every sensor i used so i was confused!

 

[kdog1988]

I believe its suppose to have an o-ring in the space

Sent from my LG-E739 using Tapatalk 2

 

[kdog1988]

Sent from my LG-E739 using Tapatalk 2

 

[jetjock]

It does not. As pointed out it's a tapered pipe thread...

 

[kdog1988]

I have to disagree I'm sure its suppose to have an o-ring as shown in the photo I posted and you can see the area where the o-ring goes in the other picture of the sensor

Sent from my LG-E739 using Tapatalk 2

 

[jetjock]

Well, I owned the car 25 years. Bought it new. No O ring. In fact doesn't make sense there would be. Funny the EPC doesn't show it either. And the rear is necked down like that for stress relief...

 

[kdog1988]

Ok well my sensor had an o-ring on it before I replaced it and the new sensor came with an o-ring

Sent from my LG-E739 using Tapatalk 2

 

[Jeff Lange]

It's a tapered pipe thread, it should have thread sealant on it as per the manual. New sensors come with thread sealant on them. There is not supposed to be a gasket or o-ring and that is not a spot meant for an o-ring, the threads just end before the hex head. Whoever put an o-ring on your car didn't need to, and I'm not entirely sure I believe your new sensor came with one, since they don't from Toyota or any other aftermarket one I've ever seen.

Jeff

 

[jetjock]

Thank you Jeff. As I said, doesn't make sense. From an engineering standpoint it's an improper application.

 

[SideWinderGX]

Jeff Lange, pretty sure its an M16x1.5 thread pitch. Can you find anywhere that it says its a tapered thread?

Those sensors are not tapered, neither are the threads in the housing. A lot of the sensors in the housing are M16x1.5, NPT and BSPT both don't fit.

 

[3p141592654]

No o-ring on mine. If the factory wanted to seal that interface they would use a gasket, not an o-ring. It would need a radial groove added to the sensor head for an o-ring application. In any case, you can tell its obviously tapered just from installing the sensor.

 

[Jeff Lange]

It has been a really long time since I've actually looked at one on a Supra. I did some research after posting and it seems like it potentially is not a tapered thread (M16x1.5 may be right). I also did see some aftermarket parts options (like Standard's TS73T sender) that do have an o-ring on them, however these are used in many applications across multiple manufacturers. I don't know why they put that o-ring on there, but it is not needed or used on Toyotas from the factory. Most of the other non-tapered sensors have washers on them, this one does not. The stepped section is potentially bottoming out on the housing?

I should do some measuring/checking further, but I might not. Depends how curious I get about it.

EDIT: This is what a new sensor looks like:

This is some info from an aftermarket supplier (I've found similar info from other sources):

Jeff

 

[SideWinderGX]

It has been a really long time since I've actually looked at one on a Supra. I did some research after posting and it seems like it potentially is not a tapered thread (M16x1.5 may be right). I also did see some aftermarket parts options (like Standard's TS73T sender) that do have an o-ring on them, however these are used in many applications across multiple manufacturers. I don't know why they put that o-ring on there, but it is not needed or used on Toyotas from the factory. Most of the other non-tapered sensors have washers on them, this one does not. The stepped section is potentially bottoming out on the housing?

I should do some measuring/checking further, but I might not. Depends how curious I get about it.

EDIT: This is what a new sensor looks like:

This is some info from an aftermarket supplier (I've found similar info from other sources):

Jeff

Thanks for the reply Jeff! I had to plug a few of the ports on the thermostat housing and the 3/8 NPT plugs I bought didn't work (duh, they need to be BSPT). Bought a few 3/8 BSPT plugs, ALL of them leaked even with teflon tape. I ended up buying 16x1.5mm plugs and those aren't leaking.

I couldn't find any concrete information on it, only a few posts on some other Toyota forums.

I was really frustrated for a few days