When ever I drive my car, and the AC isn't on, the air coming out of the vents is very warm. Even with the temperature set at 65 F or lower. Is that normal?

Oh, I drive a G35 Coupe, 6MT
<P ID="edit"><FONT class="small"><EM>Edited by JediRacer on 06/22/04 02:53 PM.</EM></FONT></P>

 

There's a DIY fix in the FAQ/DIY forum. You need to silicone the small gaps where the air is drawn from.

Russ

Black 6MT Coupe
Jax, FL
G35Driver.com Business Cards

 

Sealing some gaps between the engine compartment and the air intake plenum may help the problem, but many people (including myself) have concluded that there is likely a logic defect in the heater air-mix door control that is the most direct cause of the hot air. The feedback control system that operates the air-mix system is complex, and I believe there is a software bug.

This problem has been discussed in dozens of threads. Suggest you perform a search and read more. BTW, there is no reported case of Infiniti acknowledging the problem or providing a fix.

<font color=blue>'04 G35S 5AT, Black Obsidian/Willow, Prem/Nav/Sat</font color=blue>

 

Correct me if I'm wrong, but when you set your HVAC for fresh air (no A/C) the air that enters the cabin can only be as cold as the outside. If it's 80 degrees outside, the coldest you'll get in the cabin will be...80.
The temperature display for the interior is only for the A/C (Automatic Climate Control), where you set your desired inside temperature and let the ACC control fan speeds and the temperature. The only way you can affect inside temperature with just the fresh air on (A/C off), is by setting the desired temperature to be higher than the outside - In that scenario, by setting the desired temperature to be higher than the outside, you tell the HVAC system to adjust the air flow and pass more air by the engine - thus letting in warmer air. But if you try to set it lower than the outside, the HVAC will try to eliminate engine heat as much as possible, but the air will only be cold as the outside temp - at the least....

Am I wrong?



My G-enie

 

You're correct that you can't get colder air than what's outside.

When you don't use your A/C it draws the air from the compartement(s) where the brake fluid reservoir is and the battery. If you look closely you will see several gaps between the wheel wells and the thin metal walls for those compartments. The rubber gasket on top of those walls seals the compartment from the engine compartment so you don't draw in engine air. The problem is in the gaps because engine air is drawn in through them. If you seal those up with silicone you will notice a huge difference in the temperature of the air coming into the cabin.

Russ

Black 6MT Coupe
Jax, FL
G35Driver.com Business Cards

 

You know I have this problem too and it really does feel like there is hotter air than outside coming in. This is with my HVAC off, air coming from outside.

 

Can someone snap some pics of these openings?

Thanks.

My G-enie

 

Thanks for the responses. I did try to search the subject, but I didn't find any answers. Sorry if this has been discussed many times (unlike the wheels/suspension forum, where the same topics never come up twice )

I stated that my temp setting was at 65 F not because I would expect the air to be that cold, but just to prove that I'm not an idiot and have the temp turned up high, then complain that hot air is coming out of the vents.

I'll give the gap-sealing trick a try.

 

I think when you turn off A/C, it doesn't follow that air outside is let in. Try this when you're running on the freeway.

Turn your A/C off (everything's off, nothing on the screen except compass and outside temp). Then push Mode. This will not start the fan but will let air in. Choose which mode you want the outside air to pass thru.

Anybody tried this?

4020 P3MCG6T5I

 

I've been trying to figure this one out as well.

Along the same lines, does anyone know if you can switch from Auto to Manual with straight through airflow (i.e. without the fans) without having to hit both "Off" and then "Mode" again?!

2004 6MT/C/TB/W/Prem/Aero

 

The fan speed controller gets cooled by air passing thru HVAC box adds a degree or 2, air passing by closed heater door is warmed a little more.
About the best you can expect is 4-5F warmer than inlet air which can be 5-10F warmer than radio temp from road heat and cars in front exhaust heat..........now engine heat leaks are in addition to above.