aftermarket coolant temp sensor install advice

[nuggets]

I'm looking to replace the stock coolant temp gauge with an aftermarket gauge from PLX Devices. I already have other PLX gauges, so this should be an easy install into their system.

The PLX sensor appears to be a VDO brand 1/8 NPT fluid temp sensor. I also purchased a 1/4 bspt to 1/8 npt adapter. My plan is to replace the stock sensor with this new setup. From what I've read on this board, there's no better place than where Toyota put their sensor (go figure )

My question is: looking at the pictures below, do you think that there is enough surface area exposed for the temp sensor to get accurate readings? I'm guessing that there is, but figured that I'd get some advice from the experts on this board. I'd hate to install this and get bogus temp readings.

 

[madsupra88]

I would say thats fine.

 

[Pandaplastic]

Where did you get that adapter? I need one too!

 

[nuggets]

Where did you get that adapter? I need one too!

The adapter is from a company called Adapt All. http://www.adaptall.com/ They make tons of different adapters and fittings. The part that I got was #9042-04-02, in steel which is a 1/4 male bspt to 1/8 female NPT, but that didn't work. They also make it in stainless and brass I believe.

Unfortunately, the temp sensor is larger than 1/4. The only size larger they make is 3/8 male, so I'll have to order that adapter and try it. I'm hoping the sensor isn't 1/2. They don't sell to the public, but are very nice on the phone and will direct you to a reseller in your local area.

I also picked up some 1/8 bspt plugs and 1/8 bspt to npt adapters to fit my aftermarket oil pressure sensor.

 

[nuggets]

I would say thats fine.

Cool, I'm going to install it today and see how it works.

 

[empera]

wats the thread size on the stock coolant temp sensor

 

[nuggets]

wats the thread size on the stock coolant temp sensor

Well, I can now say that it's not 1/4 bspt . That's the size that I ordered and it's a bit too small.

I just found this thread on another forum: http://www.toyota-supra.info/forums/mkiii-supra/7498-coolant-temp-sensor-thread-size.html

Someone is saying that it could be M14 x 1.5, not tapered.

I'll experiment around with a few other adapters and see what works.

 

[Enraged]

I blocked off the stock gauge sensor with a bolt, I think it was an M12

I then drilled and tapped a hole to 1/8NPT for the sensor. I couldn't find an adapter to go from the M12 to 1/8NPT.

 

[nuggets]

I blocked off the stock gauge sensor with a bolt, I think it was an M12

I then drilled and tapped a hole to 1/8NPT for the sensor. I couldn't find an adapter to go from the M12 to 1/8NPT.

Thanks Enraged. I'll pick up an M12 bolt tomorrow and see if that fits. If so I'll see if Adapt All makes an adapter. If not, I might have to go the route that you took.

 

[madsupra88]

Just retap/thread it to 1/8 that you have.

 

[nuggets]

After much trial and error, I've found the correct size. That thread is an M16 x 1.5. egauges.com sells an M16 x 1/8NPT bushing (http://www.egauges.com/vdo_indA.asp?PN=R7964). VDO also makes a temp sensor with an M16 x 1.5 thread if you want to forgo the bushing.

 

[TurboStreetCar]

I love the search function, for anyone else Autometer also makes a fitting adaptor.

http://www.summitracing.com/parts/ATM-2268/

 

[Kckazdude]

All of these adaptors are situated too long and do not have the sensor placed in the water flow properly as pictured in the first post. My tool box has about 8 different adaptors from different vendors and they all have the same fitment issue. I finally went to my local hydraulic hose fitting distributor and had an adaptor custom built. Only cost me $15 to have it made.

 

[TurboStreetCar]

I really don't think its that crucial to have the sensor actually in the flow of the coolant. I would have a hard time believing that the temperature of the coolant would differ very much at all in the 1/2-3/4 inch the sensor is away from the flow of coolant. It would still be contacting the coolant and im sure that tiny volume would equalize with the flow moving past it.

 

[Kckazdude]

There wouldnt any difference until sediment from the block gets deposited in the void blocking off coolant flow.

 

[grimreaper]

You could always leave the stock sender alone and drill and tap the thread size you need to the side of the coolant bypase. Puts the new sender right at the top of water neck.

 

[TurboStreetCar]

Is there a reason the water bypass is there? Its completely in the way and clutters up the turbo side of the engine.

Im looking to replace the CSI time switch with the prosport 1/8th npt sender. I dont need it any longer and i use the stock coolant temp sender for the EMS, i want to rid my thermostat housing and cover of all unused components. ones i remove with no replacement will either be welded shut or replaced with a bolt and ill grind the head down just enough to be able to get it out just in case. Or maybe an allen head bolt or something.

Gonna tackle this later on, its out of season now and i have other things to take care of.

 

[grimreaper]

LEAVE THE BYPASS! I had horrible warm up times with it blocked off. Dont know how it will affect things in the summer heat, but so far ive noticed a LOT more steady temps with it hooked back up.

 

[TurboStreetCar]

I guess ill just set it up so its out of the way. Grr, just another thing to spend time on.

 

[figgie]

it is 12mm x 1.5

the bosch sensor used in porches for coolant temp is a direct drop in and coincidentally what MoTeC sells.