On hot days my N/A S4 car like to run with a little bit hotter temperature than the normal 1/4 of the gauge. The radiator isn't clogged and the fan clutch works fine so I was wondering if anyone had any ideas to make it cool better.

 

make sure your shrouds are on correctly, get a radiator panel thing (make one out of sheet aluminium... on top, mm... make sure nothing is blocking wind passage roung the radiator. make sure your thermostat is working correctly. make sure your radiator cap is good, make sure your underpanel is in one peice.if that dont work too swell, then get the koyo radiator n flow or whatever its called, heard they work fairly well. make sure your fan blades are okay.and again the most important, the shroud is okay!

thats bout all i can think of.

 

at least u have 1/4 of the gauge... i always have 1/2 at least... what's causing it?

 

S4 gauges stay at 1/4 during normal operating temps. S5 temp gauges stay at 1/2 during normal operating temps.

 

1) Increase cooling capacity
2) Increase airflow through heat exchangers
3) Make your current cooling system more efficient


#1:
One of the more popular options to do this is to run an upgrade / larger radiator.
Popular choices are Koyo and Fluidyne.
Not only do you increase the heat exchanger core, but you also increase the coolant capacity which acts as a buffer for the engine heat.

#2:
Ducting, ducting, ducting!
Air flowing around the heat exchanger is not doing anything for cooling.
Make sure the air flows through the heat exchanger core!
Stock system uses plastic panels and foam insulation.
Most of the time, the foam insulation disintegrates into dust!
Also, clear out any debris and straighten any bent fins.

#3:
Coolant additives like Redline Water Wetter and Royal Purple Ice (?) claim they will drop coolant temps by allowing better heat transfer from the engine into the coolant.
Mind you, this will not drop the cooling system temps that much.
You're lucky to get a 10F drop.


-Ted

 

Run lower octane gas and premix, if you arent already. Helped my temps tons.

 

#1 thing: OEM thermostat. Get one first, then work out other issues if that doesn't lower your temps. Auto-store thermostats suck. Get OEM from a Mazda dealer, www.rx7.com or www.mazdatrix.com. $20 + S&H, I think.

My foam is gone, my ducting and everything is stock.
Old thermostat: temp was 1/2-3/4 while going slow on level ground.
OEM thermostat: temp was 1/4 to <1/3 going up a very steep hill on a blazing hot day with the A/C on full, while having a blast w/ the throttle.

Driving with no thermostat will only be a little worse than an OEM thermostat (you need a thermostat to close the bypass for better cooling performance). Auto-store thermostats just plain suck.

 

Would a radiator panel like this help with cooling?


I'm still on my stock intake snorkle and what I was woundering was, with that panel will it not allow air to go into the intake snorkle? IDK where the air comes from for the snorkle, I was guessing from infront of the radiator which would be blocked with the panel.

Stock snorkle for referance

 

Yes, a little. But unless you've increasd your HP, the stock configuration should work great. I'd find out what's wrong before doing upgrades.

1st: OEM THERMOSTAT!
2nd: Fan clutch. With the engine shut off, there should be decent resistance when you try to turn the fan.
3rd: Check for sediment, leaks, clogs, etc., etc. I think Pep Boys will diagnose everything for $30, but you'll have to wait all day. Or do it yourself or find a mechanic.
4th: Blown coolant seals. Remove radiator cap. Warm up the engine. Coolant should not bubble or spill out. Bubbles should not appear in the reservoir with radiator cap closed.
5th: Broken water pump, clogged radiator. The water pump is designed to leak before breaking (ideally). A mechanic can clean the radiator or you can replace it.

 

Troubleshoot the stock system first:

http://www.aaroncake.net/rx-7/cooling.htm

 

Replace the thermostat, then troubleshoot if it's still a problem.

A S4 NA does not generate enough heat to overwhelm a properly functioning stock cooling system under normal driving. There's no real need for an upgraded radiator or such unless you're doing something really strange with the car (endurance racing, possibly?).

-=Russ=-

 

Yes, check the cooling system, but like i said before, start running lower octane gas, because i was running 91 up until a week ago, when i got more insurance on my 88 n/a (didnt have it insured for about a month) and started running pre-mix, runs way better, and now when i get into the throttle it stays perfectly at about 1/4 up the gauge. It actually dips below if i turn the heat on. Also feels a little bit more powerful, i believe because of the premix. I am running fairly lean with the pre-mix, but my OMP is still intact and functioning (it uses oil, and is only a 40K km old mazda reman engine). This is tried and true for me. Update us if you find the problem.