I just installed an S5 Koyo radiator on my S4.. it fits alright, but the temp sensor located on the bottom left of the stock radiator (looking outwards, from the motor) doesnt seem to have a recepticle on the koyo.. is it imperitive that i have this sensor working? i searched and someone said it was solely for the AWS.. any insight on what to do?

 

Im not 100% sure, but I think thats the sender to the ECM?

 

ECM? do you have any idea what it does? i just hope thats not the sensor that supplies the data for my coolant temp guage..

 

Yep, cold start.
Eliminate it and it doesn't do that stupid 3,000RPM cold start.
It's not that important.


-Ted

 

AHH what a relief! thanks again ted. oh yeah, ill post pics of it installed with the stock shroud later, it fit fine.

 

I have a feeling it's used by the ECU for more than just a cold start signal, Ted...

 

It's only a switch (normally open, closes above ~65degF), not a proper sensor. It controls ACV functions as well as cold start, but it's still just emissions.

 

Hey NZ, how's it going? Don't see you around much anymore...

I tested mine a while back, she contacted at right at 60*F. Since she doesn't run to 3K on startup if the temps are below that threshold, I don't really worry much about the engine blowing up, lol...

Along with the water thermo sensor, that little guy is instrumental in flooding us when we shut her down before warmup, too, I believe...

 

I got married a few weeks ago, so I've been really busy... I'm back now though.

The AWS is only used when the engine is completely cold, and that's the input the ECU uses to determine that. I imagine that in the right climate it might never even be triggered.

 

just finished everything, and the lack of that sensor is causing no ill effects.. the temp needle was pinned just above the C! lovely. i guess the real test is tomorrows highway driving

 

Mr Youngerthanmycar.......that switch does not have any effect on the water temp gauge as stated earlier.

It will effect the Relief Valve Solenoid and therefore the relief valve in the ACV ......when the water is cold in the radiator. Series four switch only. None on a series five.

Congratulations to NZCONVERTIBLE on his marriage. Just little advice on that subject......wives need a periodic tuneup and are a high maintenance piece of equipment. (humor)

 

The only water thermo sensors I'm worried about is the ECU one and the gauge one.
Screw all the other ones.

The ECU is on the back of the water pump housing.
The gauge one is right by the oil pressure sensors.

I think you can have at least 2 or 3 more, depending on year?
I know my '87 Turbo II has the extra one on the bottom of the rad and the one on top of the thermostat cover (electric fan I believe).
I really don't care about those.
Oh, my emissions is mostly pulled.
...and Hawaii doesn't really have strict emissions laws.


-Ted

 

That's cooler than it should be. Your thermostat could be stuck open. And as mentioned the radiator temp switch has nothing to do with engine temp control or the temp gauge.

Thank you.

I'll definitely try to remember that.