Ive asked this before but never got a clear answer. I have a s4, they say it should run normally at around 1/4 of the temp gauge but mine runs at 1/2 constantly. I have seen other s4 owners write about panicing and shutting off the car when they see it at half but thats how i drive everyday. is something wrong? is my motor doomed?

 

Mine run at half when I have air stuck in the coolant system. My 86 ran at half forever until I finally managed to get the coolant system up to par... damn 87 is killin me tho

 

Hmmm maybe ill try bleeding/flushing the coolant system this weekend, im also gonna change the thermostat even though i know thats not the problem.

 

An S4 should not run at 1/2 of the temp gauge. The last time mine ran at 1/2, I had a blown coolant seal.

 

Its weird thats its consistantly at 1/2, though. Normally when its at half, its on its way up. Are you using coolant? Any white smoke? If not I wouldn't be too horribly worried, just flush the coolant system with fresh coolant and see if that helps.

 

when i worked at mobile 1 here in my town the way we got air out of a cooling system is to

Step 1) let the engine cool down

Step2) take off the rad cap

Step3) start the car with the rad cap off and watch bubbles come to the top and leave the car running for nomore than 2 minutes

Step 4) if the collant level drops then add coolant

Step 5) put the cap back on

 

BKLYN,..you are doin the right thing by changin the thermo and flush and fill..just make sure to get the air out of the system when you change to new coolant..another good thing to do is to look into a water temp gauge..I'm not sure if you can put one in along with the stock gauge..but someone on the forum should know..should also be info on proper procedure to service your cooling system(flushing,proper filling.."burping" the air out..)..good luck..

 

I have a water temp gauge ill try to install on sunday. What temp should it be running at?

The temp gauge didnt work when i got the car back but i later found out the sensor was simply unplugged and since ive plugged it back in its been 1/2 constantly.

Other than the gauge i dont see any signs of something wrong with the car, motor runs strong, compression is good, no white or weird smoke.

 

Normal temp is around 180 or so, when cruising.

 

You need a real temp guages to know really what that is.

In my experience I've seen it stay at 1/2 way and the temp varied between 195-220

3/4 up is around 220-230. You never want to get near there BUT it is somewhat ok to drive like that(I did for the summer at 220 here in AZ)


Here are a few things to check to get your temps down.

-Replace your thermostat with a Mazda OEM one only(like 18 from Dealership).

-If you have removed the airpump get a dual Alternator pulley asap

-Check the tension on your belts and also see if they are polished. If they're polished/loose then they're more likely to slip and not drive the waterpump.
Over tightened belts can lead to premature alternator bearing failure.

-Do a coolant flush

-Check your radiator or try to get it cleaned

-make sure your using the stock fan. Electric fans shoudl only beused if you know how to fab a shroud and you got a big cfm fan.

-Fan shroud and undertray. Help big time. Some people say you can get away without them but I personally have seen my car not like it.

-Ducting. Rework your ducting and seal any gaps air can escape through.
Clean the air path. I cleared out 10years of leaves and stuff from between my oil cooler and AC condenser.

-If needed replace the waterpump.

Those aren't in any real order but everything there should get your cooling system in tip top shape.

 

mine used to run at halfway up, but a dual pulley and new thermostate took care of it

 

everyone here has a good idea and digitech hit it on the head. i would change the thermostat if you have never done it . its easy and quick . but since your cracking the coolant system anyway replace the coolant. if that doesnt bring your temps down then your gauge is messed up or you have another problem. but i would start with a thermostat and coolant flush.

 

When I had cooling problem, my stock s4 gauge read 1/2 gauge. Now it's steady to 1/4. I have a real temp gauge to mesure water temp correctly. 1/4 stock gauge = 180-190, 1/2 = 195 to about 215. I never got over 215 F.

I replaced the thermostat (it won't open), I replacde the radiator cap (did not get pressure) and replaced the clutch fan (it was broken).