Please Help, warm air from vents
 

Hi all, I am a new member and just like to say hi and at the same time like to hear your opinions about this issue I am having. I've had a look at other threads but i can't seem to find the answer i am looking for, and other threads don't to seem to have as much detail as i would like in the findings.

I just recently purchased a 370z and just recently did my 1000kms (621miles) service/check and I had a concern in which I brought up with the dealer in which they replied was normal. They didn’t seem confident with their answer so I am asking you guys for your experience and knowledge.

After driving the car for a while (20 mins from cold start) and once the oil temperature warms up I noticed that the air from the vents start to get warmer as well is this normal? These are my settings and findings.

AC-Off
Fresh Air (not circulated)
Temp set to coldest 18c (64.4f) degrees

In all the other cars I have ever been in, under the above circumstances the air from the vents should be very similar to the air temperature outside. I compare this by opening the window, putting my hand out to feel the breeze and then placing my hand in front of the vent, temperature has always been very similar, regardless to freeway driving or stop start traffic.

I’ve noticed that as the oil temperature rises from 90c (194f) to 105c (221f), so does the warmth in the air from the vents (more evident on hotter days), note that the above settings have not change. This happens regardless when the air outside is 20c (68f) degrees or 35c (95f) degrees but in stop start traffic.

But this morning I was driving in stop start traffic, oil temp was 105c (221f) degrees outside temp was 20c (68f) degrees and warm air poured out of the vents, BUT once I jumped onto the freeway and drove for a 5-10 mins the oil temp dropped to 92c (197.6f) degrees and the air from the vent matched the air outside the car (it has cooled down significantly).

Now one would argue that the outside air has cool engine by passing through the grill and radiator, but on a 35c degree day, when I drive down the same freeway at the same speeds with no traffic the oil temp would remain at 105c degrees and the air from the vents would be warm. But the weird part is if I turn on the AC on a 35c degree day the oil temp would drop to 95c degree and remain their regardless if it is freeway driving or stop start traffic. Since the engine would be under more load I would assume it should be hotter correct? Also if the argument is that the fans are constantly ON then what about when I drive on the freeway? I am sure that air pushing through the radiator at 100kms would be much stronger than the fans on the radiator.

I guess my question is, do you believe that keeping the oil temp to 90c degrees would solve the warm air issues from the vent? As I like to drive with windows up and AC off when the temperature permits. If so do you think an oil cooler would help in this instance would a larger radiator?

What have you experienced? Sorry about the long winded question but I really appreciate your help and opinions.

Cheers!

Welcome and congrats! Dont know an answer for you but Im sure someone will chime in.

No idea if all the fiddling to try to reduce oil temps will help, but my Z almost always has warm air coming from the vents, unless I have the AC on or it is really cold outside. Even in mild weather when I would be comfortable in my Altima with just the vent, I will need the AC in the Z to stay comfy.

your vents are emitting warm air, because the fresh air intake for your ventilation system is right in the windshield and partly the engine bay. lowering your oil temps will not lower the temp of the air coming in through the vents. the way the vents were positioned will make it so you always have some warm air coming in when your engine is adequately warm. nothing else to it.

Keep the climate control turned on at all times.

My car normally has some air blowing out of the vents even when they're turned off. That said, if i turn the knob all the way cold the air does feel cooler.

The airflow stops if I turn on recirc.

As chops says, the air is drawn from the engine compartment, so it's going to be a little higher at low speeds.

The inlet is behind and below the battery. If you take the trim piece that goes over the battery/IPDM off, you can look down and see the cabin air filter.

Warm air
 

Yup. I pulled my battery for winter storage and to do that had to pop open the battery cover, remove 3 clips and pull a panel, then another 3 clips and another panel. Lo and behold, I could see the cabin air filter through the opening where battery was. It makes sense if the non-recirculated air is pulled from the engine bay then it will always be a bit warm when the engine is up to temperature.
I've always wondered why manufacturers for cars destined for colder climates don't drop an electric heating element in the ductwork for the incoming air so people don't have to sit around and wait until the coolant system warms up to get any heated air. You'd get immediate heating and windshield defrosting.
As I see it, it's not that much different than an element that they put in heated seats. Just in a different location and a little more powerful.

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Thanks everyone for their replies, in particular chops for explaining the reason why. i guess having climate control on all the time will solve the issue. i just didn't want the AC on all the time because on other cars it robs the car of a little more power and drinks a little more on fuel as well?

is this different on the Z? is power the same with or without AC on?

The compressor is turned off when you accelerate hard so power is not affected.

You will use more gas but modern compressors are pretty efficient so the impact will be small.

On most modern cars. The A/C pump will disengage when at WOT, also when the steering wheel is turned all the way to one side or the other. Like when parking. ;)

The 370z with AC and climate control off, is a strange beast I learned. Short story, in cooler months or weeks here I would have wanted to use no AC at all, but it does not behave like other cars I have owned in this manner.

Same issue as well. Learned to live with it. I close the door vent or I turn on the climate control system but on low then hit defrost.

Most any cars I have had similar issue.

Thanks SouthArk370z & Rusty, that is a very interesting information that i didn't know before hand!

Thanks again for everyone's input!

Nice. I didn't know that