Over cooling
 

Ever since I bought my 88 a couple years ago i'v never been able to get it to warm up properly, it only reaches the 1/4 mark sometimes. At first I thought the gauge was busted or the temperature sending unit, but after doing a coolant flush myself and being alittle short on coolant the gauge reached the 3/4 mark. I'v already replaced the thermostate and it's alittle better but not where it's suppose to be. So what else can it be other than the radiator?

You generally don't want the guage going over 1/4.

3/4 is too hot! our cars like the needle around 1/4, thats perfect

1/4 is normal operating temp for S4's, so don't worry about it. I hope you used a Mazda thermostat though...

Oh seriously! I didn't know rotaries heated up differently. Most cars i'v seen are at about 1/2. Alright then thanx.

PS. So why are ppl always saying rotary engines have a heat problem

It's got nothing to do with being a rotary, it's just the way Mazda decided to calibrate the S4's temp gauge.

Rotaries don't have a "heat problem". They are more easily damaged if you overheat them though.

Warm up cold starts.

what about s5 mine always reads 1/2 way

normal ranges:

S4 = 1/4-1/3
S5 = 1/2

Stop listening to those idiots.

If you looked at the owners manual, it would tell you that 1/4 is normal.
In fact, 1/4 is about 200F approximate.


-Ted

I have been told that the stock gauges are fairly innacurate. And not very responsive speedwise.
I know once my cars finally running a real water temp gauge will be on my to-get list.

Rotaries are hot little engines, and cannot be overheated without risking frying your o-rings and needing a rebuild from that.
Gotta keep the cooling system very solid.
OE Mazda stuff is AWESOME and very built.

Stock OEM Mazda Thermostat is a must, NO aftermarket thermostats.
Any hose will work as long as you can seal it properly. I personally just buy OE mazda hoses meant for my car.

A radiator that is not so brittle that it will crack at the thought of a bad gravel road.
Inspect your stock plastic endtank radiator for its condition. Try not to play with anything more than you have to if it looks suspect, or you may be forced to replace a part due to the super brittle mazda plastic cracking.

I am going with a koyo all aluimnum race construction radiator. Holds way more coolant, looks awesome, and can be had for a reasonable price.
Lower $300's on ebay. I found mine for $240 shipped!!! Was a deal of a lifetime for a nice shiney new one.

The stock clutch fan is pretty reliable and cranks out tons more air than all but the best electrica fans can even think about. It will handle 118 degree phoenix summers, daily driven year round and I showed no mercy until about 110, and then I just moderated my boost :D Stock clutch fans are near bulletproof. Cltuch can fail, thats about it.
You may want to check its operation with either a FSM or one of the how-to guides on the forum or a rx7 website.
Unless you have some serious space issues, and have to run an electric. I wouldn't. People have success with fiero electric fans and taurus 3.0 fans from junkyards, along w/ blackmagics and a few more.
I think they have to be over 2200cfm as a minimum to be a good cooling fan for a rotary that sees any sort of summer temps.

A fan you can always go overkill on, you have an electric thermostat switch to keep that in check. Don't skimp because you never know when you get stuck on the freeway blacktop on a hot summer afternoon in stopped and go traffic.