I just got done reading the "Heated Seats Take Forever" thread and it got me to thinking, does anyone elses heat take forever to come on? My seats heat up before the heater. In the summertime, as soon as I start the car (with auto feature active) the air comes out at full force and almost cools down immediately. I wanted to see how the auto feature works in the winter thinking it would blow cold air for a minute and heat up quickly and it just remains off for EVER and then blows full force.

Is this a defect? I figure, it takes less time to heat up my house than cool it down, so why is the max backwards? I've never had a car where it takes longer to heat up than cool down. The basic concept behind heating and cooling is blowing air over hot or cold coils right? Why does it take so long for the heating coils to heat up to allow the heater to work? I got to the point where I just turn on the front windshield defrost which comes on immediately and ultimately heats up the whole car. Anyone else having this problem?

 

A car's interior heat is from the engine's coolant running through the exchange unit (heater core). You have to have the engine warm up, preferrably under load, to get heat. The coolant reaches a pre-determined temp and the thermostat opens. I recall only some older VWs had eletrical heaters, as the engines were air-cooled and not water cooled.
A window defroster (horizontal-printed lines) is electrical heater and works via conductivity. Generally located on rear windows. But a defroster-setting on the HVAC is just ducting to the lower windshield, which again, depends on air, not current.

Once my engine temperature gauge starts to rise, the heating system fan kicks in and that's it; it works.

We had -12F (wind chill) earlier in the week and it took about 5-8 minutes for the Max to warm up. Sitting, idling will not warm the engine faster, but I let it warm up while I got the trash ready for pickup.

As for heated luxuries (seat and wheel), mine are fine. Matter of fact, I am spoiled now, with the wheel getting hot fast! And I set the seats to hi, then low after warm.

Only thing I've noticed now is that I am getting a smell (moisture?) from the heating/AC system. I suspect I should change the filter? Anyone do this or did you have this done by "stealership"?

 

Excellent response, maximage. The Maxima certainly cannot deliver warm air until the source of the warm air (the engine) is warm. The air conditioner, on the other hand, works best when first turned on, BEFORE it has to overcome the heat of the engine.

In the area of heating and cooling, automobiles cannot be compared with homes. Peanuts and grapes. Or is it apples and oranges?

As to replacing the microfilter, several here have done it, and posted about it. The difficulty is that the entire glove box assembly has to be removed to get at the filter. At least that is not as bad as the old Zs, where the entire dash had to be completely removed to replace a blown radio dial light.

 

You also have a almost brand new car, so the freon is not leaking. You should check for leaks every summer. Takes two days. One day you put the dye in the system then you go back to the shop the next day and he checks with a blacklight if there any leaks.

I love the way the heat works, it doesn't bring the cold air into the car but waits for the car to heat up then blasts it.

 

What works for me is I take it off AUTO, turn off the A/C, and select the mode to feet level and center vent. Works great for me after about 1 minute. Found this out by trial and error. Now that it is working fine for me, I have no problems. I experimented with all the other settings, AUTO, A/C on.....bah, hell, it was in the 20's here and glad I finally figured out this system. Try my settings and let me know if they help you out.

 

you also live in the south where is doesn't get very cold. I don't think there is any problem with the heating system. I commonly see -10F (-25F winchill) temps here in iowa and it just takes that long for the block to heat up before the heat comes kickin out.

 

Thanks lightonthehill! I'll order a few and give it a shot...when it gets warmer..outside.

 

I thought of that as opposed to the defroster because the defroster is so loud and the manual override works well too, takes my car more than a minute tho but not much longer. I understand the principal behind the wait and blast as it was designed, but it takes longer that way so I'll improvise.

 

But I still remember being stationed at Mountain Home AFB in Idaho....nice -35 degrees with the wind chill....even then, my Camaro with a nice healthy V8 did little to warm up the heater. I feel ya. Not too cold out here, but just found the best way to make this thing work for me. Hey, actually, for the first time in 50 years, snowed out here in BILOXI MISSISSIPPI on Christmas. Kinda funny to me. Heater still worked well after a few minutes of driving.

 

I know there is a thread that talks about the rear vents, but I can't find it. I can't figure out how the rear vents work. Hooked into the front high vents? With AC on only? Fooled around with the settings but all I seem to get is rather room temperature air that doesn't seem to be affected by the temperature setting. As it is, my kid hasn't forgiven me for not getting the Elite with the rear heated seats. The least I can do is give him some heat back there. Any ideas?

 

Hooked into the front vents only. It will work on the dash vent setting. When you switch to dash/foot vents it will be reduced. If you want to get more air back there, close two of the dash vents so there is more pressure in the system, it will force more air to the back vent. It will take a few minutes to warm up the vent system from the dash to the rear section. Don't expect it instantly.

 

Thanks. I'll try it in the a.m. Although we don't get much real winter anymore in Chicago. Global warming and all that, I suppose...

 

I try to always buy aerosol cans. I puncture them when they are empty in an effort to contribute to global warming. I'm hoping that at some point we won't get winter if I keep it up!

 

Im very surprised automakers have not yet thought use the AC compressor as a heat pump, similar to the way the heat pump/AC units in households work.

For those who are not familiar with HVAC, this is a very short primer on the basics of air conditioning. A compressor compresses Freon (or 134a or similar) gas, causing it to become high-pressure, high-temperature gas. The hot gas runs through a set of coils which cool it down causing it to condense into a liquid. The liquid is then run through an expansion valve, which turns it into a very cold, low pressure gas. This cold is what you feel when the air is coming out of your vents at home or in the car. Reverse the flow of Freon (etc.) and it gives off heat.

Knowing that, why don't automakers equip cars with heat pumps? Instead of waiting for the engine to warm up, we would wait 15 seconds even on the coldest day for the heat pump/AC unit to start pumping nice heat into the cabin.

Modifying the existing design for AC unit would involve including one small valve to reverse the flow, and adding or changing the electronics in the car. The car's computer can account for the formation of ice on the coils on the exterior of the cabin (the same coils that condense water and drip in the summer would condense water and ice over in the winter, reducing the effectiveness of the heat pump... in home heat pumps this is accounted for in the electronics... the heat pump switches the system off and heats the coils causing the ice to drop off). Given the computerized nature of the entire car's systems, this is NOT too much to ask, IMHO.

So what do we say people? Let's get Nissan and all other automakers who pitch "luxury" cars to include a simple valve so we can have instant heat in the winter. Who wouldn't spring $200 for an instant heat option, especially those of us who drop $400 or more on a heated seats/wheel option?

BTW, im not an HVAC technician, but i play one on TV.

 

Thats a brilliant idea.

 

Just saw a 97K (CAD) Benz that can do some of the above... not sure of the heat pumps.. but it gets heat from the engine into the cabin "after" a stop (ex shopping mall) and keeps the car warm ... people/pets could sit in it for 20 - 40 min without the eng. running and get heat Blowing!! (also uses solar instead of the battery) BUT 97K !!!!!!!!!! and it did not have a heated wheel!!

 

Well sure, that is immediately feasible, especially considering the use of solar power to operate the blower motor. When you stop the engine, it doesnt cool down immediately, so one is able to route the heat the engine compartment still has to blow it into the cabin. The solar power is probably barely enough to operate the blower, and probably has no juice left to operate a standalone heating element.

 

Thank you, someone else understands my frustration. So obvious, yet no one has bothered. For christ sake you can watch TV in your car but you still have to wait a lifetime for the heater to come on. Why don't they focus on the basics already.

 

This thread was from a long time ago, but I just called the dealer about this. They said that cold air coming out of the rear vents is normal. It is so the rear windows won't fog up, and not so the back seat passengers can warm up. Tell that to my back seat passengers. Bad design in my opinion.....