I Have Read Many Threads Regarding This. I Am Installing My Defi Bf Water Temp And Am Debating Where To Put The Water Temp Sensor. I Found Pro's And Con's For Tapping The Thermostat Housing, But I Was Thinking Of Running A 1/8 "t" In The Upper Radiator Hose. Has Anyone Done This? Are The Readings Accurate?...

 

go to racing beats website and order the adaptor. then you attach the adaptor to tank where the sensor goes to.

 

never mind it was a part for the rx8. http://racingbeat.com/FRmazda4.htm yeah when i checked out racing beats site and found out it was for an rx8. my gauge was drilled into the water housing itself. make sure though you run the wires through a place that will get the least heat from because my sender wire got fried from the heat.

 

I think it is widely accpeted that tapping into the t-stat housing will give you the most accurate read. It isnt really that hard to do...its where I put mine.

 

Instead of tapping the t-stat housing, I tapped the hex plug in the t-stat housing that's right behind the coolant fill cap. Two words of caution tho, that plug is made from the hardest metal known to man. I had a hell of a time drilling/tapping it even with a drill press. Also the probe comes really close to the fill cap. Not a problem if you cap doesn't have "wings". I think the install is relatively clean and can be undone simply by replacing the plug and not the housing but it was kind of a PITA.

 

To the original poster: I agree with FORSAKEN, tap the thermostat side, so you'll see the actual temperature of the coolant coming out of the water pump. You will know the actual coolant temp while the car is still warming up, and if the thermostat sticks closed you'll see the correct temps.

In the following photos, you want to tap into the chamber that is visible in the second photo, not the filler neck side shown in the first photo:










ArmitageGVR4, unless your car has an FC filler neck (which it doesn't appear to), that photo shows your pressure-releif cap installed in the wrong place. The black & red cap that is labeled "0.9" is supposed to go on the AST, while the yellow cap labeled "fill cap" goes on the filler neck.


-s-

 

The throttle body coolant line is the best place to put a sender. No drilling or tapping. Easy access. Accurate temp readings all the time, not just after the t-stat opens. Here's a pic.

https://www.rx7club.com/forum/attach...chmentid=49238

 

Nice!!!

-s-

 

Good eye, but I gutted the cap so there's no spring mechanism, just a rubber gasket The cap on the AST still has its internals.

 

+1^
Really is a piece of cake and accurate. My fans come on right when the gauge say they should.

 

Use the TB coolant line. Any other method will be lots harder or will give you goofy readings.

Here's my post on the topic -

https://www.rx7club.com/showthread.p...e+body+coolant

Trust me, this is the best way to do it. Easy, quick, easily reversible, and gives accurate full-range readings.

Dale

 

Just to bump this thread, I'm about to do this, I have the thermostat housing off the car at the minute but my concern is that surely if the TS fails to open then the engine could be overheating and my gauges would be reporting no problems at all?

So the general consensus is that the throttle body line is the best place?

 

Yep!!