It's getting hot in here...
 

You're supposed to sing along to the thread title in a female teenage voice to the annoying tune that was out a while back...

With all the information on this board I'm interested what suprises you guys most about the 8 when you finally get your hands on it soon. Maybe someone can make a thread at that time. For me (and therefore this thread means it can't be for you I guess!) the most suprising thing has been just how hot the car runs.

This is one seriously hot car. It's around 30 degress here these days but even so cars should be able to take it. After an hours drive in town (jams) I park up and you notice as you get out of the car the heat it's giving off. First is the whaft of hot air you get coming out of the vents just behind the front wheel arches. The engine fan only runs for 5 seconds (ish) after you turn off the engine so you get a quick gust. Then as you stand up out of the seat you feel the real wheelarches. Standing next to them is like standing next to a gas burner!

Worried me a little so I turned the ignition back on. All the fans started up again. [BTW, I should have mentioned that parked outside my house unloading stuff, from outside all you can hear are the fans - no engine!] Opened the bonnet. The air comes in through the bottom lip where the front accent goes. Nothing goes through the front grill (where the plate is) or the side foglights - they are both "fake" grills. It exits behind the wheel arches and through the top of the battery cover! You can't see the fans as the battery, airbox and fuse box all sit on top of the radiator. You can only see the bottom of the radiator from looking through at the underside from the front.

Everything in the engine compartment was too hot to grasp. You can touch it but just for a second. The black plastic engine cover was very hot - could run without it I think. Even the hood prop was nasty to touch as it's metal!

Anyway, throughout all of this investigation the fans are running furiously. It sounds like there are 2 - one for regular cooling and another for "OMG we need backup" cooling. For several minutes they were blasting away let's say. But the temperature gauge inside the car never budges from dead centre "ok" level. I think it's rigged. If I turn the ignition off the fans stop, even though the car is still very hot.

I first noticed this on my "Day in the Mountains". That time it was only 16 degress (due to altitude) and I'd been running the car between 7-9k rpm for 30 mins or so. As I parked up to take the photos you've seen I just switched the engine off and got out. But I could hear wierd poping noises from the engine. Getting close it sounded like boiling fluid. So I turned the ignition on but the temp gauge was fine. When you turn it to "just before starting" then the fans came on. I left them for the whole time I was taking pictures - it took probably 10-15 miinutes for them to cool the car down enough for them to shut off by themselves.

Anyway - you get the idea. I wonder whether there can be any damage to the engine when switched off due to heat build up. I think the fan cut off should be when the engine is cool rather than 5 seconds after the key is taken out. If you wait for it to cool in the car park you may be there a long time!

I also feel the temperature gauge is fixed, like the oil pressure one. It winds up slowly as the engine warms but I think it has it's "max" setting set to the same as "norm".

Another bizarre tidbit for you guys to lose sleep over for the next few weeks! ;)

Forgot to mention: this also affects the ambient temperature sensor (top row, right most button on centre console). On a 30 degree day it reports around 38 degrees! I want to see how hot it can get this summer...I reckon 50 easy! (We're in Celcius here obviously!)

I would suppose the ambient temp sensor is somewhere near the grille of the car. When the car's moving, I always thought the higher than normal temperatures were due to the hot tarmac since most of the heat cannot transverse forward through the wind. When I lived in Texas and it was over 35 degrees, everything in the engine compartment of my 7 was too hot to touch. Even the plastic on the air ducts to the air filter :eek: Rotaries produce tremendous amounts of heat. This is why the FD3S had so many problems with cooling when they added those twin turbos (and accompanying accessories) onto the motor. The RENESIS should be fine.

You just cannot trust factory gauges anymore. Most of the temperature and pressure gauges aren't on a linear scale anymore. I know for a fact that Mazda changed their RX-7 gauges to the "rigged" style in 1989. Normal operating temperature (180F / 82C) on my car is about 1/4 scale. You can see the needle actually moving if you descend / ascend an incline. This is backed up with some secondary water and oil temperature gauges that I installed in my car. I hate these new "rigged" gauges. I remember reading that the gauge will keep in the "OK" position for a large range of temperatures. There was a fix for the FD3S to change the temperature gauge to a linear style one. I'll come back when I find the write-up.

Edit:
Look at this page on how to linearize an FD3S gauge. I wonder who'll have the balls to do this to their new RX-8...
http://www.geocities.com/sdrx7_club/technical.html

I think the grills by the fog lights have the oil coolers behind.

I've also found most cars I've driven are hot (especialy on hot days) when I park them up, and often have a cooling sound (plink/pinging) as parts contract, this is all normal.

What wont be normal is if they havnt engineered it to cope with all this. I trust mazda's engineers to know their business.

So the car will be GREAT in the winter :)

HA !

I was thinking about exactly the same thing, my fellow Canuck !

Cheers !

I like driving in winter, when it's cold becuase the car runs faster.
Here in Texas we get snow, and een 20-30
s for about 3-4 months. So the rx-8 would be great to drive, but then in summer when it's 95 + , like usual it would heat up real quick.

I wonder if you could rig something up to achieve that, similar to I believe most hondas (my old hondas at least). You could at least rig a manual switch for the fan in there.

It's starting to get hot here for summer (90+ F), my maxima has taken note...slight hesitation here and there, and the clutch pedal changes feel. I don't use the air conditioning either, as to not bog it down more. I wonder how the 8 performs in such heat compared to a nice, 60F day?

All cars have a rigged temp sensor.

You have air in your coolant it sounds like, from the localized boiling.

Lots of heat in the engine compartment is bad...

When Jaguar first put smog controls on the XJ-S, they put the catalysts right up against the exhaust header. In a time when emission controls totally destroyed performance, the engineers boasted how they were able to reduce power losses by putting the cat upstream where pressure is highest. They weren't so proud when the XJ-S cars soon needed all the wires and hoses under their hoods replaced as a result of being baked to death by the heat given off by the catalytic converters.

Don't think the RX-8 will get that hot, but god help us if we have a cooling problem and overheat. Sounds like it will get very hot, very fast.

a girlfriend of mine was a nanny for a couple who's XJ-S was on the third wiring harness before they figured out the problem. i don't know what they did to correct it finally.

BAD MEMORIES
 

1973 TRIUMPH STAG was notorius for running hot and overheating,i hope i will not have to constantly worry about the heating situation surely an aftermarket fan that runs longer than 5seconds would be more appropiate .While i trust mazda engeneers they have been known to f.....up.

NEWS FLASH !!!!

Rotaries run hotter than piston poppers. Just compare the exhaust temps..... you will see what I'm talking about.

Reasonably concerning, considering I live in Australia and our summers get very hot here... I'm getting a black one too, so that won't help... :eek:

it sounds like the fd( bad dream) to me. her goes round 2 on the cooling problem.

youve gotta be kidding, it better be nothing..........
________
FEMALE ADVICE DICUSSION

I took this pic at rev it up because I found it odd that the front grill is not completely perforated. In addition, Japan uses front license plates that I think would further inhibit airflow through the grill. I see myself buying a completely perforated grill when it becomes available.

just as XU and Ahura have said, don't worry too much about the heat the car is producing. Rotaries do run much hotter...on my FD, the exhaust temps read around 1200 deg F when cruising on the freeway at 80ish MPH.

and the noises that you hear is just as Ahura said as well; parts and fluids cooling. as long as your coolant levels are where they should be, and the oil is not black sludge, then the car will be fine.

if there are fears stemming from the cooling problems of the FD, then people must remember that it was the turbo system that caused all the problems. the Renesis as well as older NA rotaries won't (shouldn't) encounter those types of problems that FI rotaries did.

take care

santino

We could always install a turbo timer to allow the engine to cool down a bit before it is shut down

that sounds like a good idea. or do the "fan mod" that many have done on the RX7club Forum. even just for piece of mind.

i would rather do the turbo timer though. hacking a new car does not sit easy with me.

santino

and i would think cars with higher engine speeds would get hotter.

If you get a chance, check the thermoswitch on the thermostat to see what kind of connector it is. If it looks the same as another Mazda part, you can probably get a cooler version to make your fans turn on 20 degrees sooner (f). I did so with my FD and a Miata thermoswitch.

Another thing. Don't listen to anyone when they say having your coolant boiling is fine. It's not in any occasion. That means that part of the engine isn't being cooled right because of an air pocket, lowering the longevity.

Worry NOT
 

1.) The temp guage is real so I wouldn't worry if the gauge stays in the
middle. The oil pressue guage is like the Miata, stays at a fixed location.

2.) The side vents are functional, they vent the engine compartment.

3.) All engines get their hottest after they are shut down, no different
than anything else.

4.) Mazda has had no problem with the engines running hot in tons of testing.

5.) The popping noise is probably the heat shields on the exhaust as the
first heat soak then cool.
:p

I'd be more concerned with the high underhood temps eventually hardening the vacuum lines and hoses. Maybe just remove the plastic engine cover, especially in the summer. It's aesthetic and serves no real purpose other than to trap in heat.

It looks like Mazda has done a lot of work with underhood air flow management, (doesn't the Yamaguchi book show a diagram?) and modifying the grille area under the license plate, or removing the engine cover could have a negative affect on the cool air flowing in, and the hot air flowing out smoothly. (although I agree, the engine cover seems unnecessary)