SidewaysFC

I have a greddy temp gauge looking to hook it up somewhere. Is it feasible to use the stock temperature sensor location on the top of the thermostat housing?

Duh...the temperature will not be correct until the thermostat opens, but the temps are always hotter after it opens and close to its hottest point right when the coolant comes out of the water pump. And I don't rag on the car unless its fully warmed up...meaning the tstat is open, thus the sensor reading the right temps? am I wrong? ...advice please.

ty

den

Once the thermostat opens it doesnt stay open constantly, depending on the coolant temps it opens and shuts to keep the temps at a constant rate. To get accurate readings you will have to place the sensor before the thermostat, there is enough room on the water pump housing just before the thermostat to drill and tap for most sizes of sensors.

Makenzie71

I like to put bungs just before the radiator inlet...

scheistermeister

is that in the hose itself?

ive always been a little confused on the subject og guage installs. it is hard to drill through the metal of the water pump? and wouldnt that be a bit of an inconvience because you would have to redrill and tap when ever you replaced the pump?

Makenzie71

No, I get a piece of steel pipe and weld a nut to it that the sensor will bolt into, then splice the pipe into the radiator hose on the inlet side. From there you get the temps at their hottest.

You should NEVER tap into the waterpump housing it's self...never never never.

ilike2eatricers

Why not? Isnt that the correct way to do it? I dont get your reasoning.

Makenzie71

too much debris in the system, plus you run the chance of damaging the pump it's self.

ilike2eatricers

What debris? You're supposed to remove the waterpump housing and tap it.

Makenzie71

That wasn't mentioned here. If you say "just tap the w/p housing" some newb is gonna go start drilling holes in his car. And there are far better places to put the sensor...like in the stick location...

7th Heaven

wouldnt using your method would result in lower coolant temp readings than the motor actually has? for best and most accurate result you should drill and tap the water pump housing and install the sensor there, as that part of the cooling system is where the coolant hasn't been cooled down yet... ?

ilike2eatricers

If you put it in the wp housing b4 the tstat it most accurately tells the actual water temp in the block as opposed to after the T stat which would be off by a few degrees. Also if you put it after your tstat and it happens to fail you wouldnt know unless you kept an eye on your stock gauge. Unfortunately for s5s there is only 3 settings on the stock temp gauge cold, warm, and overheated couple minutes ago. I guess it doesnt really matter where you put it as long as you know how much the temperature change from the block to where you put the gauge is.

NZConvertible

It's not the stock temp gauge sender if that's what you meant, it's the temp switch for the stock auxiliary electric fan that some FC's have.

You can put it there but it's far from ideal. Not only will the gauge read wrong until the thermostat opens, but it will continue to read wrong if the 'stat sticks closed, meaning you'll have no indication of your rapidly melting motor.

Bollocks. Plenty of people have done that with zero problems.

It should be blindingly obvious to anyone with half a brain that the water pump has to come off the engine.

Then they deserve what they get. This isn't a game for fools, and we shouldn't have to babysit anyone who doesn't realise you can't drill holes in a mounted water pump.

You mean stock location... There are two flaws in that theory. Firstly, there are few if any aftermarket gauges with senders that screw straight into the stock gauge sender location on the rear plate (which is obviously a good location). Adaptors should be avoided with temp senders because they move the sender further out of the fluid flow that it's designed for. Secondly, Mazda obviously though the water pump housing was a pretty good location, because that's where they stuck the ECU's thermosensor.

Makenzie71

My argument was to make it clear that tapping things on the car should be avoided...and I really think that the pump housing isn't that great (despite the stock ECU temp sensor location) because flow isn't constant in the area. At any time you could be reading an accurate temp or a stale temp, depending on the thermostate and engine speed and other things. I also thought that the ECU only read the temps as "below and certain degree" and "above a certain degree"...? I didn't know it measured specifics.

The stock location IS too small for sensors usually sold with aftermarket guages but a quick call to the manufacturer will reveal what senders are available and from who that are compatible with both the block and the guage. I use Autometer guages (not the best, I know) and, by calling their customer service number, I got a list of direct plug-and-play senders for both oil psi and water temp guages to fit both my MKIII Supra and 86 Porsche 944. I have yet to call them about the 7, though....might have a hard time with it...:s

You're right about the adapters...the only ones acceptable are the ones through which the core of the sender extends fully through them.

SidewaysFC

den - i didn't know the tstat opens and closes to keep the temps at some sort of equilibrium (i hope this word works cause i just saw the movie - it freakin rocks!)

NZ - why? the coolant fills up the area the adaptar creates anyway...the sender probe would be covered with passing coolant regardless

...i need a new water pump anyway...seals went bad and its leaking out of the vapor hole. i'll just have the replacement tapped. anything else i should do while i have to swap water pumps?

Makenzie71

That's only true with a sensor that extends into the port. Have you seen the stock FC temp sensor? It's about 1/4 in diameter, if not smaller.

den

That is the stat's job, to keep the temps constant, the radiator alone cannot reduce the coolant temp to a constant level. The coolant which is diverted to the rad when the stat opens will always be between a certain temp, but the effectiveness of the radiator changes. e.g - If it is hot outside the air cooling the rad will be hotter therefor the coolant leaving the rad will not be as cool as it would have been had it had been through the rad on a cold day with cold air passing through. If the stat opened and stayed open all the time the weather, speed you are travelling and and how many revs you are doing would all control the temps which would be bad as these all vary alot.