Okay guys, about the coolant ratio. The ratio you should use is listed on the back of the bottle depending on average tempurature where you live. The guys in Canada are going to need a different ratio than people in more moderate climates.

Generally, you want to use as much water as allowed. Adding too much antifreeze makes your cooling system less efficient. Water is much better at transferring heat than antifreeze, so the more you have in the system the better off you are. The antifreeze is there to keep the water from boiling/freezing.

Also, when you're mixing your coolant it's best to use deionized water (which you can get as most any auto shop). If you can't get that, use distilled water (like from the grocery store). Only use tap water in emergency situations.

 

Add me to the list of those needing the water pump replaced. 2004 model, 49K. I've been noticing slow decline in coolant level for the past 6 months. First time, maybe 3 months until next red radiator light, then 1 month, then 1 week. I presume this will happen to more and more 8s as time goes by. I did get it replaced under warranty.

 

Are there any symptoms to the coolant leaking into the intake or exhaust that is noticable while driving or while the car is running at idle? I have had coolant disappear in the last 7K, I added some water, and now the light is starting to come on again every few drives, but it does go off.

 

Your coolant is going somewhere. Just because you don't see a puddle under your parked car doesn't mean your coolant is leaking into the combustion chamber. I never saw any indication of a leaking water pump, yet that was the problem. Take the car in and have it diagnosed by a professional.

 

From what I've read, coolant leaking to the engine will cause white exhaust smoke. What you have described sounds like what is becoming classic RX-8 water pump leaking, if you see no smoke.

 

Asmoran knows what he's talking about. Very well expressed. The other point about coolant is that it adds some anti-corrosive properties.
Paul.

 

I've had my car for 1 1/2 and I just noticed that i was running my car with low engine coolant. I checked and there was no leak. I added about half a cup. Anyone had the same issue?

 

I would think half a cup over a year and a half is probably normal evaporation. Notice that I added half a gallon after 6 months.

Just make sure your coolant loss doesn't increase.

 

My car is at 7,160 miles now and I've had the car for a year and a month. Just added about 3/4 cup of coolant into the reservoir when I noticed that it was at the low mark. Did not notice any white smoke from the exhaust or coolant puddles on the garage floor.

 

hmmm, probably should check mine too. I assumed that when I had the Mazda Full Circle inspection a few weeks back they would have noticed any coolant loss. But it wouldn't suprise me at all if they didn't even check it, just checked off the green box on the paperwork.

 

It is very important to warm your engine well before driving. THe Renesis is made of different metallic structures which expand at different rates. If you rev the engine hard before it has warmed up properly you can get combustion chamber leakage into the water jackets and vice versa, which can cause a coolant loss. Always allow your engine to warm up before driving off, and wait till at full operating temperature before you give it a big rev.

 

I never rev above 3,500 rpm and shift at around 3,000 rpm during the first 10 minutes after starting the car.

 

you should have a full collant flush between 30-60k i believe it is i havent worked at a shop since high school so its been about 7 years. that was also piston engines but a good flush never hurts when the same liquid has been sitting in your engine for too long.

they have a machine that would probably work the same for the rotary that it does for all other engines that actually cleans the whole system out and then puts in new anti freeze its great. i also suggest a transmission flush when u do the radiator flush but thats just me =D someone with more experience with rotaries might be able to tell you more correct info as this is my first 1 but i love it sooooo much im glad to join this club and hopefully meet more and more of you in the coming times

 

Today, a year after my last post in this thread, I had to add about 15 fl. oz. of coolant to the reservoir (coolant level was below the low mark with a cold engine) at 12,420 miles on the odo. Time to take it in to the dealership for a pressure test! For those who has taken their 8 in for a pressure test, how much did it cost?

 

Mine was having a similar issue - and they completely checked the system - it was fine. Chalk it up to the expansion of the coolant - every car will "vent" some coolant from the expansion tank if it gets hot enough. God knows RX-8s get hot enough!