So my s5 turbo vert over heats extremely fast and then cools extremely fast so I checked to see where the temp sensor is located, and I found it has one of those little metal probes that looks like a tiny co2 canister and it's pushed through the radiator vents on the top passenger side. Is this good placing and good way to get the temps. Or should I relocate and setup a different way?

 

for what purpose? to control an auxiliary fan?

i haven't seen aftermarket gauge actually use one of those probe type sensors in my life.

if it is to control your e-fan and it only has a single speed then there is nothing you can do to change the cycling rate.

 

No so I can use my temp gauge inside my car and see how hot it's running accurately

 

only place you can put it is in the radiator, should be about 1/3 from the top of the radiator, but that is the least accurate spot to put a sender. you have little choice with that one however.

the best location is where the stock gauge sender is on the rear iron.

 

back of waterpump housing is best place for it. If your thermostat fails closed your sensor in its current location will never see hot coolant coming from the engine.

 

on FC engines, low on the front plate on spark side is a threaded bung into the water gallery
- under the PS bracket -
it is easily removed and bushed to suit any aftermarket gauge sender

you may have to lean the PS bracket out the way while you fit it
( much easier than pulling the water pump or alt and UIM )

 

Said differently, the blocks drain plug. We're talking about a screw in sensor that comes with most all temp gauges, right. Not the push in the radiator sensor for a temp relay to power an electric fan, right? If the latter, you're looking at the wrong sensor as Karack seems to be suspicious.

Truth be told, anywhere that immediately feeds coolant to or from the water pump. The drain plug is a PITA to get to, but a good choice. Drill and tap a hole into the thermostate housing before the thermostate is also a good and from all my read the most popular choice.

From my view, even somewhere close after the thermostate is a good choice as the only time you really care about the temps is once it's opened up anyway. There is an adaptor that fits inline with the upper radiator hose. You could even make an adaptor with home depot parts(brass T and two nipples) for inline spliced either into the small coolant hoses that runs before or after the BAC since the metal fitting on the BAC is a direct pass through and that coolant feeds pretty much directy from the pump. On this latter suggesting, I know someone will disagree with me on this thread. But the arguments against just seem too much like splitting straws. To each their own.

Sidebar to Karack. I'm going to be in Vegas next week and probably the following week. With an address, I wouldn't mind coming by your shop to check out the digs.

 

his sender won't fit in either of those locations..

the rear iron is the best indicator of true water temp, although many other positions on the engine WILL work.

 

NOT the drain plug -that is in the middle plate and there is very little to tap into,, avoid playing here


,, look at your front plate


sensor seems to fit fine here, and reads perfectly well,, if slightly lower than those whacked in the outlet pipe or thermoneck
-yes- i run with the PS/AC bracket over the top



-didnt need to dislocate the stock dash sender from the rear of the block

-didn't have the issues with s5 block rear tapped point being an odd thread that there is no common cross adapter for

-didnt have issues with the bulb bottomed out before the bush

-did not have issues with it being lazy on the wrong side of the thermostat
( like fittings tapped into the thermo neck or intercepting the top hose )

------------

like i pointed out,, this is the easiest location to get at without stripping the UIM and alt or water pumps to tap the water pump

you simply exchange the plug
,, no need to tap your block
,, the bush required to adapt down to 1/8 NPT that most aftermarket senders are is easily found at any parts shop

and if you have a 70's mazda with a retrofit engine
then you will find the large mazda ( piston ) 1/4 NPT water temp sender threads here directly without bushes

 

LOL That IS the coolant drain plug. And, engine out of the car it is a piece of cake to get to. In the car, at least if the AC bracket is still there (note bracket mounting stud locations in his picture), it IS a PITA to get to. And getting that plug out could be a real PITA even if exposed like that what with typical rust build up on the coolant side of the plug. If you go that direction, use the EXACT size allan wrench fitting so you don't strip it and use the socket type if available. First hand experience............

Everything else he indicates is right on.

All said, besides being a good place for the sending unit, it is THE perfect place to mount a sacrificial zinc anode to deal with electrolysis issues.

Right or wrong side of the thermostat is the splitting hairs thing I was referring to from my view. Technically correct and time and skills available the best place besides the drain plug location. But practically speaking not necessarily the end all mounting location. Do you really care about the water temps when they're below 180/190 degrees where the thermostate would fully open up?

Me, I installed the Zinc Anode at the drain plug and located my sensor elsewhere.

 

Back on subject, it really sounds like the OP is talking about a sensor for an electric fan.

Answer, yes that is the right place for it as that area is nearest where the water comes in from the water pump.

 

Correct about the switch for the electric fan, sorry I was not clear about it. And the stock S5 temp reader for the temp gauge inside the car is the the barb behind the water pump below the plastic neck correct?

 

For the record, there are a number of links in the FAQ covering temperature sensor locations and installation.

 

no it's not, the coolant drain plug is right in the middle of the driver's side engine mount... lower left side, 14mm long bolt. it's the lowest point on the engine for a reason.

 

I guess someone has never flushed their coolant system....

 

I just installed my coolant sender where bumpstart put his. It was a 3/8 NPT thread on my S5 turbo iron.

 

Ok, ok. I stand corrected. Doesn't change that it's a PITA to get to if the AC bracket is in place.

Then what is the official purpose of that plug if not to drain the block?

(Mental note to take a closer look at the block in the garage)

 

I have to check out that plug on the front plate. Seems like a good place since I dont have a/c or p/s. But in that area, isnt the water flow coming straight from the water pump??

 

/\ no
the flow around the motor is axial first,, not radial

this flow map will spell out that this point is in fact near the end of its path through the engine

 

it's just an accessory port, keep in mind these irons have had the same basic casting design since the 70's.

 

thats great then.
I guess I found my new temp sensor location. Ive been using those coolant adapters in the coolant hose for 2 years, hasnt failed but having it in the engine is more accurate for the readings.