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I replace the engine, new radiator, new fans. Same issue. And i still have the car still love; but the true is the true. Anything above 110° F the car will not start easily. That'st the rx8 wether you love it or not. The only reason haven't set this car on fire is the fan kit that i istalled. When you have to deal with a shity situation like that with such a good looking car and fun to drive machine believe me it's beyond frustrating. If you're an rx8 owner. You know what I'm talking about. By the way i leave in miami. My new engine is not even a year old.
I feel as though this post should be stricken from the record, as it is a grammatical nightmare of epic proportions and it is full of bad information.
I replace the engine, new radiator, new fans. Same issue. And i still have the car still love; but the true is the true. Anything above 110° F the car will not start easily. That'st the rx8 wether you love it or not. The only reason haven't set this car on fire is the fan kit that i istalled. When you have to deal with a shity situation like that with such a good looking car and fun to drive machine believe me it's beyond frustrating. If you're an rx8 owner. You know what I'm talking about. By the way i leave in miami. My new engine is not even a year old.
No, I don't know what you're talking about, as far as a HEALTHY engine is concerned. Have you changed out the spark plugs, coils and wires (and verified that all are connected AND working properly), new starter or new battery? Is your air filter clean? Ess? New coolant? HAVE YOU CHECKED THE COMPRESSION? Just because you got a new engine, doesn't mean that it's fine. "New" engine failures are defintely not unheard of...
Anyways, this is getting off topic.
If the engine and the components are ALL healthy, then there should be no issues in the normal operating temp range.
I keep seeing recommendations to replace radiator. Why is this? what goes wrong with it? Properly maintained (correct fluids, no electrolytic corrosion) the radiator 'should' last the life
That line at the top was a typo. I also restated it as a last resort. But if all else fails then it likely needs to be replaced. Properly maintained is the key words. If your coolants not changed every couple of years it gets pretty nasty and starts gumming stuff up. There's a nice mix of steel and alum in our engines and no anodes to prevent corosponding so it's all left to the coolant.
220 at a stop in traffic in high ambient temps is well within the normal operating range. For a hot running rotary 220F is pretty good for that scenario. Do you own another car? If so see what those temps are under normal operating conditions and you will see that 220F is completely normal, and actually quite low (my Jeep sits at 215F even in cold weather at idle, my bosses SLS around 225-230F) even for pistons engines.
Also completely sealing the radiator is not recommended either, some air needs to be able to escape (go around) at speed. 230F is not bad for our engines unless you are running 230F all day, every day. The occasional 230F is not going to hurt anything, plenty of track guys see that every race weekend. The Factory service manual states 243F is the danger zone, which is why the coolant gauge doesn't move until then.
The story about 220F being bad for our engines is all over this forum. It's even on the "new and potential owners" thread. Plus, I've heard too many horror stories of the temp needle moving and then having to rebuild the engine. The general rule here is that if you're above 220F, you're in new engine territory. If the coolant temp gauge moves, it's too late. That's what I read everywhere on this forum, and that is why I try my best to keep the coolant temps below 220F.
You seem to be the only person who says otherwise, and I somewhat agree with you. I've seen local RX-8s overheat (temp needle goes off center) and years later they still run fine. If the risk of losing a coolant seal at 220F is really a myth, then we need to bust that. We gotta change what's on the "new and potential owners" thread. Same story with the temp needle moving. Too many people on here think that the temp needle moving = new engine. It scares the bejesus out of new owners.
I have a 2008 Mazda 3 and in similar ambient temps, it idles at 194F. Fans on high speed and AC on. I'm assuming the AC forces the fans to go on high speed, hence the low coolant temps. The same happens in my RX-8, AC on in 95F weather forces the fans to go on high speed. It stays around 194F for a few mins, with the fans on full blast, and then slowly starts going up to 220F. I don't know if it goes any higher than that, because as soon as it gets to 220F, I turn on the heater. It probably does go higher. I've also found out that turning off the AC drops the coolant temps just as fast as turning on the heater. I guess the extra heat the condenser puts out is too much for the cooling system in that weather.
Originally Posted by Steve Dallas
I am going to disagree with this somewhat. Mazda used a thick block of foam on the bottom of the radiator, and thin foam strips on the top and sides for a reason. Some outside air is supposed to reach the engine compartment to cool the other bits from the heat created by the exhaust manifold. Completely sealing around the radiator prevents outside airflow into the engine compartment, and that is not a good thing.
When I replaced my OEM radiator with an upgraded Koyo, I sealed it completely with pipe insulation. The result was cooler coolant and insanely high engine compartment temps. I went back and removed the top foam completely, then cut 2" gaps in both sides to allow some outside air to reach the engine compartment. That brought the ECT's back down to normal.
Ah. It's summer all year over here. I'd rather have low coolant temps than low engine compartment temps. Cool air can get into the engine bay from the wheel wells and underneath the engine.
Originally Posted by fishjuu007
I replace the engine, new radiator, new fans. Same issue. And i still have the car still love; but the true is the true. Anything above 110° F the car will not start easily. That'st the rx8 wether you love it or not. The only reason haven't set this car on fire is the fan kit that i istalled. When you have to deal with a shity situation like that with such a good looking car and fun to drive machine believe me it's beyond frustrating. If you're an rx8 owner. You know what I'm talking about. By the way i leave in miami. My new engine is not even a year old.
You seem to think that the fan kit is the only thing that keeps your engine cool. The fan kit you have doesn't increase the speed of the fans. It just turns them before the car gets too hot. The fans work fine without the fan kit, it's just that it turns on when the engine gets hot. But here's the thing, doesn't matter when the fans turn on, if the fans are not spinning fast enough, you will overheat. Think about it. The stock fans go on high speed at 213.8F. Your fan kit will turn the fans on high speed somewhere around 185F. You overheat at 230F. So, with or without the fan kit, when you're approaching 230F, the fan are already on full speed!
185F might be the fan on temp, but if the fans aren't powerful enough to maintain the coolant at 185F, it's not gonna stay at 185F. You can turn on the fans as soon as the car starts, when the coolant temp is 50F, but if the fans are not moving enough air to MAINTAIN that temp, it's gonna overheat.
The lower temp fan mod DOES NOT work when sitting in traffic. However, it does help when you're on the move.
And no, getting the coolant over 220F does not burn out the starter motor. Unless, there's a coolant leak and hot coolant is spraying onto a connector that leads to the starter. Unlikely, but it could happen I guess.
And again, no. A healthy car should start fine regardless of the ambient temperature. Since you got a new engine, I'm not gonna jump and say compression. Maybe there's something else going on. Have you checked the coils?
I appreciate all the great ideas and support guys. So far with the fan kit my temperature never hit 200° F. It works for me and I'm beyond happy with it. If anybody is struggling with thier rx8 at least they know what fixed mine. I also got this idea from the rx8 forum. Plus my 8 start right up everytime regardless if it's hot or not. people don't ask me if something's wrong with my car during hot start anymore. @rx8soldier who cares about grammar in a chat room nowadays. It's 2016 dude.. you're talking to an accountant son. anyway, u sound like a kid who's new to the rx8 circle excited and all that smh. You'll remember me later. Us, rx8 owners, we love it for the fun, we respect the rotary for the power at high rpm; yet, we know all the drawbacks. Mazda knows it too. Do your homework buddy. @ Steve Dallas, I understand that it sounds crazy to you, but these are facts and my experience; the kit turns both fans on at the same time at high speed at 186°F even though the manual says 185°F , and very quickly the temperature drops to 177°F, then turn right back on. If you live in Miami, I'll bring the car to you, so you can see it with your own eyes
Last edited by fishjuu007; 01-12-2016 at 09:13 AM.
@rx8soldier who cares about grammar in a chat room nowadays. It's 2016 dude.. you're talking to an accountant son. anyway, u sound like a kid who's new to the rx8 circle excited and all that smh. You'll remember me later. Us, rx8 owners, we love it for the fun, we respect the rotary for the power at high rpm; yet, we know all the drawbacks. Mazda knows it too. Do your homework buddy.
What the **** are you rambling about? I didn't mention anything about grammar.
I only educated you on normal operating temperature....
EDIT: I can understand that you likely confused me with the guy who posted ABOVE me, but you're still rambling about nothing.
Last edited by RX8Soldier; 01-12-2016 at 04:26 PM.
I might have the only RX8 that can go back to 175 deg after hitting 200.
I have a 2007 6spd auto, and had to install a big 18,800btu tube radiator for the ATF.
On a 70 deg day, I can run the hell out of it, and then, drive it like granny, and it'll go below the 180 thermostat closing temp from 200 deg or whatever.
I might have the only RX8 that can go back to 175 deg after hitting 200.
I have a 2007 6spd auto, and had to install a big 18,800btu tube radiator for the ATF.
On a 70 deg day, I can run the hell out of it, and then, drive it like granny, and it'll go below the 180 thermostat closing temp from 200 deg or whatever.
Yes, in 70F weather, even my car would drop to 180 when cruising down the freeway. But not when idling in traffic on a 95F day. That's where all RX-8s over here plummet and die. By that I mean the coolant temp goes above 220F
When I said there's a risk of killing the starter and the battery when the temperature goes close to 220° F is because the rotary engine loses compression at high temperature by nature; in other words hard too start when too hot (if you don't believe me on that, call mazda and ask them) which means the starter will have to spin longer before firing the engine. Some people don't undertand when that happen they must wait for a little bit and try again, so they don't kill both the starter and the battery. I can tell that you have good knowledge about rx8 and I respect that. I can't force you to belelive me, but my 8 never reaches 200°F again ever since I installed that fan kit which specially design for the 8. Hard start problem gone which is the reason I changed the egine. The new engine didn't fix it; then they made me buy a new radiator, a faster starter, performance coils and spark plug. Did I see a difference? Yes, but not enough to start the car right up when the engine goes beyond 115° F. I monitor my engine temperature everyday using a coolant temperature gauge. I ended up spending over a thousand trying to solve this problem to the point where I decided to sell it, but no luck; regular car buyers are scared of the rotary. Did I see the fan kit on the rx8 club forum before I even spend a dime? Yes, but my knowledges in mechanic didn't allow me to consider it as a solution. Now I might keep my 8 until it becomes a classic. I own other cars, but for some reason I feel alive when driving the 8.
Originally Posted by RX8Soldier
What the **** are you rambling about? I didn't mention anything about grammar.
I only educated you on normal operating temperature....
EDIT: I can understand that you likely confused me with the guy who posted ABOVE me, but you're still rambling about nothing.
When I said there's a risk of killing the starter and the battery when the temperature goes close to 220° F is because the rotary engine loses compression at high temperature by nature; in other words hard too start when too hot (if you don't believe me on that, call mazda and ask them) which means the starter will have to spin longer before firing the engine. Some people don't undertand when that happen they must wait for a little bit and try again, so they don't kill both the starter and the battery. I can tell that you have good knowledge about rx8 and I respect that. I can't force you to belelive me, but my 8 never reaches 200°F again ever since I installed that fan kit which specially design for the 8. Hard start problem gone which is the reason I changed the egine. The new engine didn't fix it; then they made me buy a new radiator, a faster starter, performance coils and spark plug. Did I see a difference? Yes, but not enough to start the car right up when the engine goes beyond 115° F. I monitor my engine temperature everyday using a coolant temperature gauge. I ended up spending over a thousand trying to solve this problem to the point where I decided to sell it, but no luck; regular car buyers are scared of the rotary. Did I see the fan kit on the rx8 club forum before I even spend a dime? Yes, but my knowledges in mechanic didn't allow me to consider it as a solution. Now I might keep my 8 until it becomes a classic. I own other cars, but for some reason I feel alive when driving the 8.
Is this fan kit making the fans spin faster than stock? Like, is it providing more power to the fans?
Ah. It's summer all year over here. I'd rather have low coolant temps than low engine compartment temps. Cool air can get into the engine bay from the wheel wells and underneath the engine.
I'm glad you succeeded where Mazda's engineers failed.
According to my service manual 110 °C (230 °F) is the normal service range coolant temperature. The S2 needle is designed to begin moving from center at 110°C. Previously I shared tha tthe boiling point of coolant is very pressure spedific. A healthy coolant system is under normal pressure so 110 °C is OK so long as your coolant system is healthy. As pressure falls, that normal coolant range falls to prevent boiling (inefficient cooling + poor flow from "bubbles".
A few posts up, everyone was talking about not sealing around the radiator completely, because it would increase your intake air temps. A few days ago I was cruising with a friend of mine in our RX8s while talking (had a FaceTime audio call going. Don't worry it was on speaker lol) and we were just monitoring coolant temps, intake air temps, fuel trims etc. Now his car doesn't have sealing AT ALL. It's all open. Even the factory sealing has been blown off. So all the air that's supposed to hit the radiator, should go straight into the engine bay. What I noticed was, our intake air temps matched. It was almost exactly the same. If mine was 167F, his was 168F. If mine was 170, his was also 170. It was almost the same or super close. Both of our intake temps dropped when we started moving. So, I don't think sealing up the radiator increases intake air temps. It might increase engine compartment temps, but it's not enough to heat up the intake, and actually heat up the intake air temps. Even without the sealing, the fans throw a lotta heat at the intake. That alone is enough to heat it up. I don't think the extra engine bay temp is enough to affect the intake. His coolant temps were higher though. Because he hasn't sealed around.
The exact pressure of the coolant system also needs to be measured. Coolant boiling point is highly dependent on pressure - which is why our cars run so well in extreme heat is that we have pressurized coolant systems. If your pressures are different between cars by a few psi, this translates to different heat transfer surface conditions (how close you are to boiling, nucleation of coolant bubbles, etc).
The cooling system uses pressure to further raise the boiling point of the coolant. Just as the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi), which raises the boiling point another 45 F (25 C) so the coolant can withstand the high temperatures.
PG chart of boiling points shown as example - different for EG.
Sure, and I don't want to argue without data, but assuming 2 cars have the same coolant level (and the same glycol/water proportion!) and no leaks, they should have the same pressure at the same temperature. Boiling point of 60% glycol at 14 psig is something like 260F... a bit beyond the ranges that should occur in a car. Certainly if your rad cap has deteriorated and only holds 5 psi, you could start boiling at 230-ish... but still far above normal operating.
The graph above covers the range between near vacuum to atmospheric (assuming total pressure means absolute pressure, rather than gauge), so I don't super follow the application here.
Okay so my RX8 overheated due to the coolant reservoir busting open, My car over heated completely, Blew coolant all over my engine bay. Whats the MOST DAMAGE that could have happened??? Need help, freaking out worried that the engine was damaged also. I just purchased a new reservoir, cap and fl22 coolant.
Okay so my RX8 overheated due to the coolant reservoir busting open, My car over heated completely, Blew coolant all over my engine bay. Whats the MOST DAMAGE that could have happened??? Need help, freaking out worried that the engine was damaged also. I just purchased a new reservoir, cap and fl22 coolant.
It's good etiquette to start a new thread, but the worst that could have happened is your engine has warped and coolant seals are ruined. So, new engine Sorry, you asked.
When you start your own thread, can you describe what the temp gauge was showing? For sure there would be coolant everywhere if the tank burst, that doesn't mean it actually got too hot if you shut it down in time.
01-11-2016, 12:28 PM
THUG LIFE! 
Sorry, you asked.
