So I've searched some and kept my eyes open for mentions of this, but haven't gotten a good answer. My '87 TII is completely stock, and if anything in the next several months I'll just add a turbo timer, maybe replace the cats with a straight through setup, and possibly open up the intake with a cone filter. I'm wondering how hot the car should (and shouldn't) run and how much I should trust the stock temp gauge. I know fully well the hazards of overheating, however that knowledge is useless without knowing how to prevent it or when it's getting dangerously warm.

Typically I've been seeing ~5/8 reading at its hottest, but on the highway last night (prly ~80 degrees F ambient temp) I was at about 2/3 (still less than 3/4). What should the S4 TII's read at?

 

at idle and cruising my temp gauge (S4 'vert cluster, S4 TII engine) hovers at about 3/8 or so, but I havent really gotten on it very hard cause i'm still on break-in.

 

the s4 and older guages are actually real guages, the just arent labeled

it should run about 1/3 of the way up, give or take a needle width.

C is about 65c and H is about 110C

 

hm.... that concerns me. like I said, last night in decent weather with the A/C on just a little I peaked at 2/3.

 

Told you it was running hot.

Step 1 is to replace the thermostat. My NA was running a bit warm one summer, replaced the thermostat, and everything was fine again. They get old and sticky, or don't like to open beyond a certain point, so you don't get full coolant flow through the radiator, and things get warm.

-=Russ=-

 

^ +1

Don't forget to get the OEM thermostat. From what I've read and seen, S4's should read about 1/4 to 1/3, while the S5's are right about in the middle.

 

well, just ordered a thermostat from Mazda. sucks I'll have to wait at least a week to get it...

 

Also do you have the radiator trays? upper and lower (under the car)?

 

My 88 Vert varies from 1/4 - 1/3 most of the time but I've seen it hit 5/8 a couple of times when driving the hell out of it on a hot day. My 91 Turbo stays just a little under 1/2 no matter what which just proves what eveyone says, they read off/on/fubar.

Go here and have fun.

http://fc3spro.com/index.html

 

Pretty much. Normal temp on a S4 is 1/4 to 1/3rd. It's OK if it's hotter than that for periods of time, but there'd better be a good reason (just coming off a track run/hard autocross run, in traffic with the AC blasted on a 110F day, etc).

S5s have a worthless gauge. Cold/normal/rebuild. First mod for a S5 should be to get a real temperature gauge.

-=Russ=-

 

^
Ah, true. An S5 temp gauge that reads high means that you overheated 5 mins ago.