2017 MX75D Air Conditioning

[Falcon73]

We took our car out to the desert last weekend and the A/C was struggling keeping up. I've noticed that the A/C doesn't seem to work that well in general but I don't know if it's a temperature sensor problem or what.

If I set the car to 70 it's typically about 78 inside in the shade or even now at night when it's 59 outside.

Over the weekend when it got up above 100 in the desert the fan speed was going up to 9:00 in the interior temperature was in the low 80s.

The air coming out of the vents does feel relatively cool but what temperature should it be?

Is there anything else I should try as well?

 

[brainhouston]

Had few 90s deg days and notices AC is weak too... guess its due to all the glass
Its struggling to keep up or cool down when car sits in the sun and interior is really hot.
The air out of the vents is cold when holding hand right next to it

When i took an automotive AC class many years back, the expected temp from vents was 42deg if memory serves right and evaporator threshold for freeze prevention was generally set to 32-36deg...

 

[GasNah]

I had the same feeling while driving this weekend and I found it strange that the inside of the car didn't feel as cool as I had set the temp to be. I did have the MX in Range mode so not sure if that made a difference since range mode affect the AC.

 

[Falcon73]

I turned off Range Mode a few weeks ago to see if it would help, but if last weekend is any indication, no...

I'm looking to improve the windshield tinting. I already have the windshield shade.

 

[brainhouston]

I had the same feeling while driving this weekend and I found it strange that the inside of the car didn't feel as cool as I had set the temp to be. I did have the MX in Range mode so not sure if that made a difference since range mode affect the AC.

i forgot about range mode, mine was on...
will test without it n see if i feel any difference.

 

[henderrj]

Do you gentlemen have the extra air conditioning for the rear seat? I understand the five seaters have less AC available than the six and seven seaters. We were considering a used model x, but it was a five-seater, and I was worried about this specific issue. Well, and the fact that I could only see five people!

 

[brainhouston]

Do you gentlemen have the extra air conditioning for the rear seat? I understand the five seaters have less AC available than the six and seven seaters. We were considering a used model x, but it was a five-seater, and I was worried about this specific issue. Well, and the fact that I could only see five people!

i do but never used the rear AC or heat haha
gonna have to try it next 90+ deg days...

 

[Falcon73]

Do you gentlemen have the extra air conditioning for the rear seat? I understand the five seaters have less AC available than the six and seven seaters. We were considering a used model x, but it was a five-seater, and I was worried about this specific issue. Well, and the fact that I could only see five people!

There are vents back there and I know they work when the car is parked, but as for their effectiveness while driving, I don't know. We don't have an easy way to test it as our 3rd row is always folded. (no kids)

 

[henderrj]

There are vents back there and I know they work when the car is parked, but as for their effectiveness while driving, I don't know. We don't have an easy way to test it as our 3rd row is always folded. (no kids)

I was thinking that if you started the rear AC, I'm assuming you can do that from the center console, that it would help cool the entire cabin. Unless it uses the same compressor, and thus you just spread the cooling out. I'm not sure how it works.

I own a Model S at this time so don't have any experience with the X that helps me that way. Should have tested it when I had that loaner last time!

 

[brainhouston]

I was thinking that if you started the rear AC, I'm assuming you can do that from the center console, that it would help cool the entire cabin. Unless it uses the same compressor, and thus you just spread the cooling out. I'm not sure how it works.

I own a Model S at this time so don't have any experience with the X that helps me that way. Should have tested it when I had that loaner last time!

There's for sure only one compressor (pretty sure all dual systems are like this) but lots more freon for dual system so its possible to get more cooling i guess from dual system with same load, will have to test it...
Yes u can turn on back AC/heat from MCU

 

[Need]

We just drove over to Palm Spring last weekend and it was 100+ degrees. Our 2017 MX 5 seaters seems to be fine. We set it at 68 AUTO. It remember my left hand was too cold because the fan was blowing directly on it so I have to turn it toward the driver side windows.

 

[Falcon73]

The May Gray has mostly been in effect since we got back from the Desert.

However, I have made some improvements, as follows:

• Changed top part of windshield tint to 5% with ceramic. Very little heat gets thru it now, the sun came out briefly a couple times over the w/e, but it still gets hot, from absorbing the heat.
• I added reflective insulation under the 5% tint.
• We have the same sun shade under the window tint and insulation
• I added reflective insulation to the top FWD windows, but it didn't quite fit, so I will improve it.

I am considering maybe adding tint to the factory tinted windows as well, especially the hatch window, but I don't think I'd want to do 5% (Limo tint) on those. Any other suggestions are welcome.

My wife's MY gets the garage and that makes a huge difference, obviously, when parked in there. She has a shade on her roof glass as well. I tried adding a shade canopy to the driveway last year (before we got the MX), but that was vetoed mid-project, lol. We have a tree growing that will provide decent shade in a few years, maybe...

 

[mxnym]

I am considering maybe adding tint to the factory tinted windows as well, especially the hatch window, but I don't think I'd want to do 5% (Limo tint) on those. Any other suggestions are welcome.

It has been a while since I've looked into tint, but IIRC, I either discovered or was told (or both) that some lighter tints can actually reflect more heat than the darkest ones. If you're going the DIY route, the various tints should have specifications so you can find one that will make very little difference in the darkness vs factory, only outstanding question would be how much heat it can reflect back through the dark factory tint.

 

[Falcon73]

I'm starting to wonder if the cabin temp sensor is faulty, especially with the wild reading on Scan My Tesla for it.

Lately, I've been setting it to 68 and the inside temp is typically around 74 (at that setting).

I added more insulation today too.

Yeah, darker tint seems to absorb he heat quite a bit and re-radiate it into the cabin. So, I'm insulating the parts of the windows that aren't visible for driving purposes anyway.

 

[GasNah]

I'm starting to wonder if the cabin temp sensor is faulty, especially with the wild reading on Scan My Tesla for it.

Lately, I've been setting it to 68 and the inside temp is typically around 74 (at that setting).

I added more insulation today too.

Yeah, darker tint seems to absorb he heat quite a bit and re-radiate it into the cabin. So, I'm insulating the parts of the windows that aren't visible for driving purposes anyway.

I was also thinking that maybe the interior temp sensor might be faulty giving false readings