Sting2

Hello everyone, I have a problem with my RX-8 2004. When I use the cold air no problem, same with air conditioning. The air is identical in all the vents. But when I put the heat, and although one side is released, the other, well the air is pushed without heat. This is not the thermostat the problem because I have heat and cold ... So where the problem?
- Fuse?
- A "door" inside the connectors blocked?
- Radiator Heater?
- The "core" (it must be clean, if so are there any tricks without going to the dealer?)
- A connecting pipe?

I look the car inside and everything seems to be well connected. My needle temperature is normal ...

Thank you for helping me on this strange case!

Nadrealista

I have exact same problem 04 year as well. I get heat only on the passenger side!?

9krpmrx8

iTrader: (46)

It's been discussed many times. Search AC Amplifier.

Sting2

9krmprx8 : I soldering and I have 0-16 A/C Temp, no problem. It is when i've put heat, driver side = cold, passenger = hot at the same time when I go to the hot position...

I think is the Core? Need flush?

Nadrealista

so I took a look at the vent system schematics and I am not sure how is it possible for us to get cold air out of the driver side upper vents and hot air out ot the passenger side vents..

Looking at the vent paths on this schematic this should be impossible but that is what is happening with mine!? Once in heating mode all air goes trough heather core so how we get cold air on one side and hot air on the other in not clear to me unless they split airflow right after the heather core. If that is the case than heater core needs flushing.

Sting2

I think this is the problem, I will go to flushing ...140$ at the garage!
I will send a new msg if the problem is solved, because here is the winter in canada!

Sting2

Nadrealista : Thank you for your help and the plan!

Sting2

The car is flusing this morning, a lot of garbage, now the pestone is new. But the problem occur... cold driver side / hot passenger side. I think it's probably a door problem (the guy at the garage check this possibility).

Nadrealista

keep us updated. I am really curious what the problem is!

Sting2

Look :

- Cleaning, flush and fill new cooler
- Air mix actuator OK
- Air flow mode actuator OK
- Blower motor OK
- Blower resistor OK
- HVAC control OK
- AC Amplifier OK
- Compressor AC OK
- Sensors AC OK
- Temperature is 30F more cold on defrost, vent, floor and sides on driver side
- 50% less power of vent on driver side

All of this cost me 250$... The guy said that is probably a plastic door inside jaming or broken ...
For repairing, is 1000$ (10-12 hours of labour)

Anyone have an idea? a DIY? Put air inside? Wire?

Thank a lot for your response... I have my car since 3 months

Nadrealista

Sting I did a bit more searching and it looks like you mechanic didn't do such a good job flushing your heater core. maybe he just flushed the coolant system which will not do much good for unplugging the heater core.

Some other forum members had same problem and ended up flushing the heater core with CLR. I am going to do the same procedure myself - have your mechanic redo the flush as described below:

https://www.rx8club.com/showpost.php...80&postcount=6

Ok. Heat is working again, and it is now coming out burning hot. Since I see a bunch of people having this issue, I wrote up some instructions of what I did.

1) From the image below, I have indicated where the heater core is, the intake hose coming out of the engine block, and the outtake hose going back into the engine block after passing through the heater core.

2) The intake and outtake hoses can be removed at a few places, but I've indicated where I found it to be the easiest to access and to fit a garden hose. In order to access the outtake hose, you will have to remove the battery, and it's compartment completely. This is not difficult, as there are only a few bolts in the assembly and it comes off in several pieces.

3) The radiator hoses are held by a clamp. You will need pliers to release the tension and slide the clamp off the nipple (this is the pipe that the hose fits onto). The clamps can be difficult to remove, but wiggling them back and forth while forcing it down the hose helps.

4) Once the clamps are off, you will have to pull the radiator hose off the nipple. This is a bit difficult as its stuck on pretty good. I first rotated the hose to break it loose, and then I rotated as I forced it downward off the nipple. It will take some muscle and you will likely end up with calluses, but it will eventually come off. You can also buy a tool that will make it easier to remove, if you want.

Note: I removed the outtake hose first so I can drain the line from coolant (though there isn't very much). There is not much room to move the hose once its off the nipple, so I stuck a plastic shopping bag underneath to collect whatever coolant drained.

5) Take a garden hose and use a high pressure nozzle. Something like this is what i used: http://images.orgill.com/200x200/6813729.jpg

6) We want to backflush the heatcore, so you need to stick the garden hose in the outtake line. I connected some spare hose i had to the intake line and ran it into a bucket. I didnt have a great seal, but it was good enough that it didnt spray all over the place.

When I did this step, i immediately saw in the bucket some gunk that probably was blocking the heater core from passing hot coolant through.

7) Now you want to flush the heater core from the intake line to the outtake. Alternate between intake and outtake a couple of times to make sure its all out and the water is running clean.

in between these steps I would also pour CLR into heater core and let it soak 10-15 min and flush it again like this guy did; https://www.rx8club.com/showpost.php...06&postcount=6

8) After you've cleaned out the core, let the water drain out well from the outtake line. Once clear, slide the radiator hose back onto the nipple of both the intake and outtake lines. This can be a bit difficult, especially with the outtake line, but with some muscle and rotating it back and forth while pulling it up will eventually get it on. Once positioned, take your plier and slide the clamp back onto the nipple where it was before.

9) Put back together the battery and start up the car with the hvac off. Let the engine properly warm up before turning on the heat to test if its working. Once the heat is running, grab a flashlight and check the radiator hoses to make sure there are no leaks. Also, once the engine has cooled, open the coolant reservoir and fill it back up to the indicated line to replace the coolant that was drained.

Nadrealista

one more bit of useful information:

the passenger side tube coming out of the firewall of the engine compartment traces to the top of the heater core under the dash and the driver side tube traces to the bottom of the heater core. you want to poor whatever liquid you decide to use in the tube that goes to the upper part of the heater core so gravity can do it's job.

the problem with the design of the heater core and why they keep clogging up is because both the inlet and outlet tubes are on the same side of the heater core so, if there is a clog in the heater core, water won't flow through it, and simply passes in one tube of the heater core and out the other tube of the heater core. And since the tubes are both on the passenger side of the heater core, that is why you are still getting warm air for the passenger vents.

New Yorker

Didn't McDonalds once have a sandwich that utilized this principle?

Sting2

I've got CLR and I will try this week for cleaning the heater core! I'll keep you informed.

Cohort

iTrader: (4)

ugg i tried both of these and it didnt work at all. I even used radiator flush. This **** is ******* annoying as hell.

Nadrealista

I need to do mine as well but it is not a daily driver so I am putting it off until spring :-)

M RX 8

iTrader: (1)

hello, I have same problem but flushing dosen't work for me
I boiled some clr cooler flush, then poired in to heater core and leave for 10min (do this 3 times). Also flush with some calcium cleaner, then flush with clean water both direction. All time water was clean, nothing come out.
When I turn heater&fun FULL is blowing LEFT corner 97[°F] and RIGHT 140[°F].
I just thinking they are any separate door for air running to left/right tube
I check mechanism located in center console (next to driver legs) and work ok
I just scare about taking all dashboard out...

jano

i have a rx8 2004, my heater dosent work,I tried the power button and up scan and all I get is all the icons on display light up and and a/c temp.
i did some search and i saw the guys teaching how to pull put the unit and soldering the 3 conections, but I'm not sure if its my problem?
someone can help me please?

https://www.rx8club.com/series-i-tro...3/#post2673979

nycgps

iTrader: (1)

test the control **** first. it's 90% of the problem

JohnF

its summer, and my RX-8 has a working AC - sorta...
The air blows cool on the passengers side, but acts like i have the heat turned on to temper it on the drivers side.

The previous threads on this seem to be the opposite... regarding half of the heater not working when heat is needed.

I do not need any heat... its 90 here in Fla.
I've looked at the diagrams and don't see how the drivers vents could be different than the passengers vents.

Is there a way to completely turn off the heater core - to see if that fixes it?

is there a "heat valve" somewhere that could be leaking hot water into "part of the core" but not the whole core?

I'm totally mystified by this behavior... help!

Jumboss

hello. i amnew here,

i have big problem with hot air on driver side. on passenger side air works good but on driver side its all time hotter. AC clima works ok. its same problem if i blow air from outside, on passenger side is same temperature as outside, but on driver side is alltime hotter...

can someone help me?

04Green

iTrader: (1)

This is most likely a flow problem, as in how fast the water is moving through the core. In your case, not fast enough. The part of the core that is ducted to the driver side is the farthest away from the inlet, and the water is cold by the time it gets there. You get this in a AC that is struggling, with cold air only available to half the car. I am running a remedy pump (lower flow, but better on track) and have the problem you describe. Coupled with a cooler thermostat, and a huge radiator, the winter weeks are a bit tough.

First, insulate the line from the driver side, across the firewall, to the inlet to the heater core.
Then, find the restrictor in the line running from the heater core to the thermostat and remove it. This may get you some more flow. Now, if any of these lines are bent or kinked, fix that as well.

Both my 04's were this way.

chevaliernoir

I have exactly the same trouble as you guys.
In addition I have the issue that if I choose to use air from outside, tehre is a bas exhaust gaz smell, and I feel I would be intoxicated in few minutes (then I use only "Recirculate" mode)
It's automatic A/C in my case. all the control work fine, except that left air blown is always hot, and the left front defrost is not efficient at all.

On my case it started after an engine rebuild, and 6 month with no engine in the car

The solution that everyone refers too is about flushing the heater to improve the heating, so it is not our solution, for sure.
One outcome anyway is that, for people with heating issue, is that even is the air flow is theoretically the same for right and left, a hot or cold area in the system would result in warmor cold flow in one side of the vehicle.

Thank you for sharing you experience

rotorhead62

Have had the problem in the past, Replaced heater core and now have heat on both sides.