Ottoman

on my S4 TII

when the car is warmed up and sitting at idle.. the needle is barely into the C---H zone...

in general is the Temp gauge supposed to go up and down under spirited driving and such?

or is it supposed to warm up, and then stay solid at whatever temperature and not move?


if i really get on it a few times.. the Temp can reach half way mark...

what is it supposed to be like with a rotary?

NZConvertible

S4's have a linear temp gauge that does move in proportion to temp. It will rise a little as the engine temp increases under load. As long as it doesn't keep going up it's fine. Yours sounds like it's running too cold though. About 1/4 is where most people report there gauge normally sits. If you don't know its age, you should replace the thermostat with a new Mazda one.

S5's have a 3-step gauge that only reads cold, normal or overheated...

Ottoman

oh i see....

so how high is too high would u say? is half way still "safe"?

if i Get an aftermarket Temp gauge like an Autometer..

can i just splice it/ Replace the original temp gauge, and retain the stock Temp sending unit?

or will i require using the autometer supplied one?

cluosborne

If you get an aftermarket temperature gauge, you have to use the sending unit that comes with the gauge; stock one won't work.

On an S4, too high would probably be over 1/4. But, a factory gauge isn't the most accurate.

I'd run an oil temperature gauge and install the sending unit into a replacement oil pedestal with two 1/8" NPT ports; makes the installation very easy and reliable. While you can run a water temperature gauge--perfectly fine to do--there's some debate on where to install the sending unit. Do a search and judge for yourself.

With oil temperature I can tell you that on my N/A, depending on the outside temperature, the oil temps can range from 160 at cruise to over 180 with spirited driving. If it's hot outside, the the temperature can approach 200. Operating temperature is typicall 180-210, over 210 is an overheat condition.

So yes, temperature can change.

Syonyk

Cold, Normal, or "Overheated 5 minutes ago, your coolant seals are toast, I thought I'd let you know."

My S4 gauge runs around 1/4 normally, 1/3 with the A/C on, and up to 1/2 in hot weather with the A/C on in traffic. I tend to worry if it hits 2/3rds, that's when the heater gets kicked on full blast (defroster vents are the most effective for blasting out heat without baking the driver). That usually only happens if I take an autocross course in 1st gear (spending a good deal of time on the rev limiter, probably cavitating the water pump badly).

-=Russ=-