Heating/Ventilation question
 

on my 05 RX-8 Sport, when i'm using the heat and want the air directed at my feet and press the mode button and direct it that way, i also get air coming out of the defrost vents as well. so i have feet and defrost when i only want feet heat. so i consulted my owners manual first and foremost and it indicated that thats the proper way the air should be being directed in the feet setting. now why do you guys think that is? i realy think that its not a great idea. i for one dont always want defrost when i'm trying to heat my feet. i finally found something i really dont like about my RX-8. its tolerable but mildly annoying. are ay subsequent years different?

You're correct.

The way the system is designed, there is always a little 'leakage' of system air coming out of the defog vents when the selector is on floor position (and vice versa).

If the uncommanded air volume is excessive, you could have a problem with the airflow mode actuator on the driver's side of the blower.

If I were to guess, I'd say the idea is to avoid a huge temperature mismatch between the cabin air, and the windshield glass - could cause fogging under some conditions.

However, this 'feature' seems does seem to be one of those odd design eccentricities of the RX-8 (and Japanese cars in general). Not too many folk consider this a big deal...

its not a huge deal but i guess i'm too used to my RX-7's.... the heat temperature isnt really really warm..more of just a warm air unlike what i'm used to in my 7's with their eye drying heat. engine temps are great. i may look into replaceing the thermostat. i might call the dealer today and order a new one..

mazdaverx7

You obviously have an aftermarket temperature gauge if you know that your engine temps are 'great' (the factory temp. gauge is a 3 position 'dummy' gauge, after all).

If the engine temps are 'great', then why would you think of changing the thermostat?


In answer to your question, though:

There is a known issue with bad solder joints on the circuit board in the temperature controller. This results in no-heat, or erratic less-heat conditions.

Here is the thread (It is a STICKY in the DIY forum) with testing and repair instructions: https://www.rx8club.com/series-i-do-yourself-forum-73/diy-no-heat-repair-heater-control-158200/

thank you for the link and info. no aftermarket gauge, just stock. i was basing my assumption on that gauge. according to that, the temp needle stays where it should and other than that i have no fact to support my engine temps other that the fact that it doesnt overheat or underheat(basing it on the oem gauge). no pressurization of the cooling system into either housing and no overheating due to corroded housings or bad coolant seals or o-rings. at any rate, no loss of coolant and no excessive or under normal engine temps. heat is warm but not as good in previous rotary powered cars.

after a longer drive in the car today and with an ambiant temp of 18 degrees, the heat worked very well and was extremely adequate. i guess i had just not turned it up enough on the fan speed...

It does take a little bit for the thermostat to open I have found. When it does finally open...you will stay warm.

the 8 really doesnt like this cold ohio weather on first startup. the heat has been realy good today. maybe it was my fault for not dirving the car longer distances. i've put just over 200 miles on the car since i bought it.. i need mooe stick time behind the wheel to explroe the car. its a hard car to stay out of.

Come hang with us in the spring after we all bring our cars back out. We'll get you goin just fine. :P

i normally wouldnt drive the 8 in the winter but i just bought it and you know how tough it is to stay out of anyways. i'll hang with you guys..you're a bit over an hour away from me.

i would have the 8 in the garage but i'm restoring another 7 and doing a GSL-SE engine swap into it, which isn't at all too plug and play. after that's finished, the 8 will go in the garage. http://www.rx7club.com/showthread.php?t=796342

and don't worry my friend, i'm no stranger to the rotary :)

my BB 88 TII and my 88 10AE:
http://i246.photobucket.com/albums/g...7/DSC07085.jpg

85 S:
link to its restoration: http://www.rx7club.com/showthread.php?t=751475
http://i246.photobucket.com/albums/g...7/DSC06968.jpg

80 Leather Sport:
http://i246.photobucket.com/albums/g...7/DSC03715.jpg

85 GS i bought wrecked:
http://i246.photobucket.com/albums/g...7/DSC06541.jpg

85 GS i'm converting to to an 85 EGI setup:
http://i469.photobucket.com/albums/r...b/DSC07395.jpg

http://i469.photobucket.com/albums/r...b/DSC07439.jpg

http://i469.photobucket.com/albums/r...b/DSC07418.jpg

http://i469.photobucket.com/albums/r...b/DSC07466.jpg

http://i469.photobucket.com/albums/r...b/DSC07457.jpg

I grew up 20 minutes east of you in North Ridgeville. We have a 7 person in my other club that autox's with the rest of the guys. We really should move this over to the Cleveland/Akron thread though. I really don't want to shit on your thread about heating ducts and how fukt up they are. :P

I'll get us back on topic... :)

Remember... the thermostat opens based on engine/coolant temp.
At roughly 180F the thermostat starts to open and should be fully open at roughly 200F.
If its taking longer (meaning its not fully open by roughly 200F) then you may have a defective thermostat.
It simply opens by melting wax within the cylinder (which is why it starts opening at 180F).

thaks for the info. i noticed that the heat really stars kicking in hot when the engine temp gauge shows the needle close to the half way point, which i can ASSUME is CLOSE to normal operating temp. being that i have been driving the car for longer distances and cranking the heat, i notice how warm it gets....i believe that everything is in working order. i still do not care for the defrost being on when i only want the heat blowing on my feet. other than that my complaint about the lack of heat is all but squashed.

i'll have to start browsing in the Cleveland/Akron forum and see what you guys are up to in there!

Thanks Jon...I meant as in it takes longer than other cars I have owned. Doesn't make much sense to me based on how hot a rotary runs...but it is what I experienced.

Just know that the coolant temp gauge is not all that accurate. If I remember correctly it only knows 3 positions. Cold...normal...and "Oh Shit Oh Shit...you boiled the coolant"

thats also good info regarding the gauge. i know its not a linear gauge but i was hoping it was more accurate than only a three position gauge...