Heat only getting really warm when car is moving (2016 CX-9)

For the sake of this thread (and to satisfy my own curiosity), I actually went out and did a little test with my 2018 CX-9 and my 2006 Civic. The Civic has been sitting outside in minus 40 to 50 degrees C for the past few days, and as such, would barely even crank over when I tried to start it when I got home earlier today. It was a little warmer today (about minus 30 degrees C) so I decided to plug the block heater in and put it on a trickle charger so I could get it started, stretch its legs a little bit in the evening, and swap spots with the CX-9 (since I use it more often than the Civic). The CX-9 had been sitting in my uninsulated garage for about six hours since I got home from work, with ambient temps in the garage hovering around minus 20 to 25 degrees C.

After letting the battery charge for six hours, I went out to start the Civic up. It starts perfectly fine, which is great. I take it off the block heater, turn the heat on and set the fan to two clicks away from max, with air directed to the footwell/driver, recirc set to off. Then I go to the CX-9 and start it up. I set the air to the footwell/driver setting, set heat as high as it will go (which oddly is only 29 C), recirc also set to off. I go back inside and let both cars warm up for almost 20 mins.

When I go back out, I get in the Civic first so I can drive it around the block and also get it out of the driveway so I can move the CX-9. I notice that the Civic is now blowing warm air, but it's not really hot, which is sort of what I was expecting. Engine temp is just out of the "cold" zone after taking it around the block. Now I step into the CX-9 to move it out of the garage, and lo and behold, the air coming out of the main vents is nice and warm (but still not really hot). Fan is now running at full speed and the cabin has warmed up enough to the point where I'd be comfortable strapping my baby into the car seat. I press the INFO button to check the engine temp, and while it has warmed up a bit, it's still in the blue section and the cold temp indicator is still on. So basically, my experience differs completely from that of other owners in this thread.

What the hell is the deal?? Lol
 
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For the sake of this thread (and to satisfy my own curiosity), I actually went out and did a little test with my 2018 CX-9 and my 2006 Civic. The Civic has been sitting outside in minus 40 to 50 degrees C for the past few days, and as such, would barely even crank over when I tried to start it when I got home earlier today. It was a little warmer today (about minus 30 degrees C) so I decided to plug the block heater in and put it on a trickle charger so I could get it started, stretch its legs a little bit in the evening, and swap spots with the CX-9 (since I use it more often than the Civic). The CX-9 had been sitting in my uninsulated garage for about six hours since I got home from work, with ambient temps in the garage hovering around minus 20 to 25 degrees C.

After letting the battery charge for six hours, I went out to start the Civic up. It starts perfectly fine, which is great. I take it off the block heater, turn the heat on and set the fan to two clicks away from max, with air directed to the footwell/driver, recirc set to off. Then I go to the CX-9 and start it up. I set the air to the footwell/driver setting, set heat as high as it will go (which oddly is only 29 C), recirc also set to off. I go back inside and let both cars warm up for almost 20 mins.

When I go back out, I get in the Civic first so I can drive it around the block and also get it out of the driveway so I can move the CX-9. I notice that the Civic is now blowing warm air, but it's not really hot, which is sort of what I was expecting. Engine temp is just out of the "cold" zone after taking it around the block. Now I step into the CX-9 to move it out of the garage, and lo and behold, the air coming out of the main vents is nice and warm (but still not really hot). Fan is now running at full speed and the cabin has warmed up enough to the point where I'd be comfortable strapping my baby into the car seat. I press the INFO button to check the engine temp, and while it has warmed up a bit, it's still in the blue section and the cold temp indicator is still on. So basically, my experience differs completely from that of other owners in this thread.

What the hell is the deal?? Lol

That is great that you did this test. Very much appreciated. A couple things to consider:
1) From what I gather, Canadian CX-9s may be different.
2) You are comparing the CX-9 that you drove six hours ago that is kept in the garage with a car that hasn't been driven in 3 days kept outside in -50. I'm sure the internal temp of the Civic was much colder than the Mazda.
3) In your test, you had the blower of Civic set to two notches below the max, and you indicated that the Mazda was blowing at full power.

If I let my car run in the garage for 20 minutes, it is definitely warmer than when it started, but it is incomparable with my Rav 4, Subaru, and Acura MDX. With my other cars, I would have to turn the heat down when I got in. In addition, all of the other cars after 20 minutes, the engine indicator shows the engine fully warm, while My Mazda is not even close. When I start driving, it then warms the engine and the car starts to get warm. The issue is not that the car doesn't get warm enough in the winter, it is the timing it takes. If I have to run to the grocery which is 2 miles from my house, that is not enough time to fully warm up and starting the car in advance doesn't help. If I drive 30 minutes, the first part of the trip is not very warm. Still a great car.
 
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For the sake of this thread (and to satisfy my own curiosity), I actually went out and did a little test with my 2018 CX-9 and my 2006 Civic. The Civic has been sitting outside in minus 40 to 50 degrees C for the past few days, and as such, would barely even crank over when I tried to start it when I got home earlier today. It was a little warmer today (about minus 30 degrees C) so I decided to plug the block heater in and put it on a trickle charger so I could get it started, stretch its legs a little bit in the evening, and swap spots with the CX-9 (since I use it more often than the Civic). The CX-9 had been sitting in my uninsulated garage for about six hours since I got home from work, with ambient temps in the garage hovering around minus 20 to 25 degrees C.

After letting the battery charge for six hours, I went out to start the Civic up. It starts perfectly fine, which is great. I take it off the block heater, turn the heat on and set the fan to two clicks away from max, with air directed to the footwell/driver, recirc set to off. Then I go to the CX-9 and start it up. I set the air to the footwell/driver setting, set heat as high as it will go (which oddly is only 29 C), recirc also set to off. I go back inside and let both cars warm up for almost 20 mins.

When I go back out, I get in the Civic first so I can drive it around the block and also get it out of the driveway so I can move the CX-9. I notice that the Civic is now blowing warm air, but it's not really hot, which is sort of what I was expecting. Engine temp is just out of the "cold" zone after taking it around the block. Now I step into the CX-9 to move it out of the garage, and lo and behold, the air coming out of the main vents is nice and warm (but still not really hot). Fan is now running at full speed and the cabin has warmed up enough to the point where I'd be comfortable strapping my baby into the car seat. I press the INFO button to check the engine temp, and while it has warmed up a bit, it's still in the blue section and the cold temp indicator is still on. So basically, my experience differs completely from that of other owners in this thread.

What the hell is the deal?? Lol

Wow, we both have 2006 Civic and 2018 CX-9 machine grey. I compared both of mines as well and once car worms up enough HVAC perform similar. The issue I have with the CX-9 is untill it gets driven at speed for few minutes, the air coming from vents is cold and not full speed. Once the temp gauge is passed the blue portion, it works fine.

My cars are both parked on driveway so the cold overnight temps are a factor. The Civic seems to worm up at idle after about 5 minutes but the Mazda does not when I remote start it. With my previous V6 Lincoln MKX, it just seemed to worm up better at idle. My guess is emissions control system is a factor causing it to not worm up till driven.

CX-9 HVAC performance was acceptable level until recently when our temps started dropping towards -30 C. Now when I start driving, if I get stuck in traffic before engine worms up, hot air will not come out of vents. After few minutes of driving above 50 kmh, it is fine.
 
That is great that you did this test. Very much appreciated. A couple things to consider:
1) From what I gather, Canadian CX-9s may be different.
2) You are comparing the CX-9 that you drove six hours ago that is kept in the garage with a car that hasn't been driven in 3 days kept outside in -50. I'm sure the internal temp of the Civic was much colder than the Mazda.
3) In your test, you had the blower of Civic set to two notches below the max, and you indicated that the Mazda was blowing at full power.

If I let my car run in the garage for 20 minutes, it is definitely warmer than when it started, but it is incomparable with my Rav 4, Subaru, and Acura MDX. With my other cars, I would have to turn the heat down when I got in. In addition, all of the other cars after 20 minutes, the engine indicator shows the engine fully warm, while My Mazda is not even close. When I start driving, it then warms the engine and the car starts to get warm. The issue is not that the car doesn't get warm enough in the winter, it is the timing it takes. If I have to run to the grocery which is 2 miles from my house, that is not enough time to fully warm up and starting the car in advance doesn't help. If I drive 30 minutes, the first part of the trip is not very warm. Still a great car.

You're correct in points 2 and 3, and I took these points in consideration when I did this test. The end result was that the Civic and the CX-9 both had a similar warmth in the cabin (warmer than the ambient temp outside). I had the Civic's air turned down a little to account for the smaller cabin. The fact that the CX-9 only warmed up as quickly as the Civic, and not faster, despite being parked in the garage, further illustrates that while I don't seem to have the same issues others do, this HVAC system doesn't perform as quickly as many are expecting. Personally, though, I find it to be working perfectly fine.

Also, if we consider the behaviour of only the CX-9, it was blowing warm/hot air even while the engine hadn't warmed up properly after idling for 20 mins. This is contrary to the experience NY owners seem to be having (still blows cold air after idling for 20-30 mins), and also contrary to the experience teknowiz is having. Thus, the issue doesn't seem to be based on model year or on region, at first glance.

Wow, we both have 2006 Civic and 2018 CX-9 machine grey. I compared both of mines as well and once car worms up enough HVAC perform similar. The issue I have with the CX-9 is untill it gets driven at speed for few minutes, the air coming from vents is cold and not full speed. Once the temp gauge is passed the blue portion, it works fine.

My cars are both parked on driveway so the cold overnight temps are a factor. The Civic seems to worm up at idle after about 5 minutes but the Mazda does not when I remote start it. With my previous V6 Lincoln MKX, it just seemed to worm up better at idle. My guess is emissions control system is a factor causing it to not worm up till driven.

CX-9 HVAC performance was acceptable level until recently when our temps started dropping towards -30 C. Now when I start driving, if I get stuck in traffic before engine worms up, hot air will not come out of vents. After few minutes of driving above 50 kmh, it is fine.

As mentioned above, this is different from the way my CX-9 seems to operate. During my test, warm air was blowing despite the engine temp gauge still being in the blue (cold) section. Something is definitely weird here as both of our CX-9s should be warming up the same way in theory.


I'm going to attempt the test again right now.. The car has been sitting outside overnight in -25c, and it is currently -17c. The block heater has been plugged in overnight as well.
 
So, started the car at 2:07pm. All HVAC settings were still set to the same conditions as before, air directed to footwell/driver, recirc off, heat set to 29c. I also noted that at startup, the RPMs hovered around 1500 for a few seconds (maybe 10?) and settled to around 1200. Engine temp gauge is at the coldest reading. Again, ambient temp outside is about -17c. I took it off the block heater and went back inside.

20 mins later, I went back out. Here's what I found.

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In the pics you can see that the fan is still two notches away from max, meaning that the system knows it hasn't warmed up enough to blow at max strength. You can also see that the temp gauge is still in the blue, the cold engine indicator is still lit, and RPM is hanging out at around 900. The fan was blowing hot air, and the cabin had warmed up an adequate amount, though if I had to go somewhere I would not have turned it down just yet.

Again, this is opposite behaviour of what others are experiencing. I don't know what the deal is here, but maybe you guys can use this information and my documented experience to your own advantage with your local dealers or Mazda Corporate.
 

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I find it interesting how many of you let your cars idle for such a long time before driving. It's really not good for the engine....

https://www.youtube.com/watch?v=xKALgXDwou4

Excellent video and sure to upset some remote start fans. Contrary to the frustration, this is not a Mazda design flaw at all, but rather by design. The demands for ever stricter emissions standards now rule the day. Add in outlier low temperatures and it is no surprise that things dont operate in the ways we are accustomed to.

Has anyone simply tried putting a sheet of cardboard in front of the radiator? Traditionally that was always the best way to get more heat in the cabin during extreme cold.
 
Excellent video and sure to upset some remote start fans. Contrary to the frustration, this is not a Mazda design flaw at all, but rather by design. The demands for ever stricter emissions standards now rule the day. Add in outlier low temperatures and it is no surprise that things don*t operate in the ways we are accustomed to.

Has anyone simply tried putting a sheet of cardboard in front of the radiator? Traditionally that was always the best way to get more heat in the cabin during extreme cold.

For the record, I only "let the car warm up" for these two tests. I'm a start it and drive kind of guy.

Again, the point is that it doesn't seem to be by design because my CX-9 doesn't behave the same way that other owner's CX-9s seem to behave. Meaning that there's something else going on here. For any other drivers, can you perform the same test with your CX-9s? Set your HVAC to the same settings, and note how long it warmed up for and the engine temp gauge reading.

Also, the CX-9 has an active shutter system in front of the radiator. It's plenty visible when you look through the front grille.
 
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...it doesn't seem to be by design because my CX-9 doesn't behave the same way that other owner's CX-9s seem to behave. Meaning that there's something else going on here. For any other drivers, can you perform the same test with your CX-9s? Set your HVAC to the same settings, and note how long it warmed up for and the engine temp gauge reading.

I can appreciate your regimen in breaking this issue down, but considering the total number of variations in conditions, Im not sure that other owners anecdotal interpretations of their experiences can definitively determine some sort of design flaw here. The varied outlier weather extremes do not support a controlled scientific method.

If the thermostat is designed to stay closed while idling, Im not sure what else can be done?
 
I used to have an Audi with the 1.8T engine, and I distinctly remember an owner*s manual recommendation that the car be driven immediately after start (i.e. no idle warmup). I don*t remember how long it was before the cabin warmed up in the winter, but the heated seats worked reasonably well to keep things tolerable in the interim.

After the Audi, I purchased a Nissan. The Nissan will warm up the cabin at idle after a cold start, but it takes a while, and it never gets *hot* unless I get the engine over 1500 RPM. If I start driving and only make a short trip, the heat will drop off to lukewarm at stops. Once the engine is fully warmed up, the heat will stay hot at idle, at least for a little while.

I am considering replacing the Nissan with a CX-9, and the reports of *weak* HVAC are a bit of a concern. I need cold A/C in the summer and *hot* heat in the winter, even at idle (assuming the engine is at normal operating temperature). And, I need defrost to work quickly, which is not a problem in the Nissan.

I did test a 2019 CX-9 and thought the ventilated seats worked great, but the heated seat function seemed to take forever (10-15 minutes) to get hot in a cold car, which quite frankly I consider unacceptable. It sure would be nice to let it idle for a few minutes and arrive at a warm car, but it is likely true that idling isn*t the best for modern engines.
 
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I have a 2016 CX-9 signature. I have noticed that during the winter, no matter how long I let my car warm up, it doesn't get really warm until I drive the vehicle. I let my car warm up for 45 minutes yesterday and the car was slightly comfortable when I got in it (slightly warme) and I had it set at 84. As soon as I started driving, it started warming up substantially more. I then noticed when I get to a stop light, the air is barely warm and when I start driving again the heat comes out with more power and is much hotter.

This is extremely frustrating living in upstate New York. We have three other vehicles including a Subaru SUV, Acura MDX and Toyota RAV4. Each of these cars get so warm after warming up in the driveway for 15 minutes we have to turn the heat down. With the CX-9, I keep it at 84 while it is warming up and almost for the entire time I'm driving. I have never had a car where my foot had to be on the accelerator to get really warm air out of the vents. Is anybody else experiencing this?
I have a new 2021 Mazda CX9 doing the same thing. Dealer says this is the way it was designed and is normal. If I had known this ahead of time I would not have purchased the car.
 
Just to jump in here, I too noticed that it takes a while for the car to warm up all the way to normal operating temperature. However, it doesn't really need to, and can get out of the "cold" running mode. Once the needle starts moving towards the hot zone, it starts to blow warmer air.

We've had quite the cold snap lately, and even in -33C I've noticed that it will warm up even on shorter drives. However, the car has a block heater and it's always plugged in, but fully exposed to the elements as I made the big mistake of buying a house without a garage (what was I thinking?!?). I can't say I see this as a horrible problem (or specific to the CX-9, my '97 Prelude would take a while to warm up too), my only concern is that I fear the GDI engine's intake valves might foul up as it rarely reaches normal operating temperatures to burn off the carbon, but honestly short trips are the main culprit there.

I typically don't run the remote start for long. I typically start the car when we start getting our winter coats on. For me, the intent is to warm up the engine oil a bit so that when I start driving it will provide some protection. On a very cold day, about 2 to 3 minutes of running should do it.

As for the block heater, it heats up the coolant directly and the engine oil indirectly. So the block heater prevents any risk of damage that might be caused by poor quality antifreeze. It does however warm up the coolant enough that I notice the window defrosts all on it's own even on cold days while it's plugged in. It appears as though the warmth of the engine coolant, even though it's not being circulated via a pump, still transitions throughout the system to the point where it can warm up the windshield. I'm speculating there, it could be just the sun warming it up, hard to say, but I did notice that patches of ice get defrosted naturally somehow down by where the windshield vents are, so it seems the block heater makes a noticeable difference. I must admit, I'm a little worried to see what my electricity bill will be for this month. 🤪

As an aside, you're probably best to keep your fan on a low position until you get in the car. The heater core is basically a second radiator, so a fast fan will actually cool down the coolant and make it take longer to reach normal operating temperature. And blowing cold air into the cabin isn't gonna make the engine warm up faster.

Last point: For those without a block heater, try inserting something in front of the radiator to partially block the air flow. Not FULLY block it, maybe 50%. And never do that with the inter-cooler. Some might say that's terrible advice, but I drove a car through the Rockies with what later turned out to be a clogged radiator in August during a heat wave (cooling systems tend to be over built so that they can handle cruising speeds up the side of tall mountains with full trailer cargo in tow). 50% blockage in -30C is probably still too permissive.
 
Same issue with my 2019 cx-9 in Toronto. The car never warms up when idling in the winter no matter how long you wait. You have to drive it to get the cabin warm. We have two infants so it really blows, no pun intended. I was debating on a remote starter, but it would be useless in the winter time. I also find that the climate control setting is not accurate. When set to 22 degree Celsius, it blows super hot. I find myself turning it down to 19 to get a comfortable temperature. My other car and previous cars I’ve owned never had this problem and neither did my old Mazda 3.
 
Just to jump in here, I too noticed that it takes a while for the car to warm up all the way to normal operating temperature. However, it doesn't really need to, and can get out of the "cold" running mode. Once the needle starts moving towards the hot zone, it starts to blow warmer air.

We've had quite the cold snap lately, and even in -33C I've noticed that it will warm up even on shorter drives. However, the car has a block heater and it's always plugged in, but fully exposed to the elements as I made the big mistake of buying a house without a garage (what was I thinking?!?). I can't say I see this as a horrible problem (or specific to the CX-9, my '97 Prelude would take a while to warm up too), my only concern is that I fear the GDI engine's intake valves might foul up as it rarely reaches normal operating temperatures to burn off the carbon, but honestly short trips are the main culprit there.

I typically don't run the remote start for long. I typically start the car when we start getting our winter coats on. For me, the intent is to warm up the engine oil a bit so that when I start driving it will provide some protection. On a very cold day, about 2 to 3 minutes of running should do it.

As for the block heater, it heats up the coolant directly and the engine oil indirectly. So the block heater prevents any risk of damage that might be caused by poor quality antifreeze. It does however warm up the coolant enough that I notice the window defrosts all on it's own even on cold days while it's plugged in. It appears as though the warmth of the engine coolant, even though it's not being circulated via a pump, still transitions throughout the system to the point where it can warm up the windshield. I'm speculating there, it could be just the sun warming it up, hard to say, but I did notice that patches of ice get defrosted naturally somehow down by where the windshield vents are, so it seems the block heater makes a noticeable difference. I must admit, I'm a little worried to see what my electricity bill will be for this month. 🤪

As an aside, you're probably best to keep your fan on a low position until you get in the car. The heater core is basically a second radiator, so a fast fan will actually cool down the coolant and make it take longer to reach normal operating temperature. And blowing cold air into the cabin isn't gonna make the engine warm up faster.

Last point: For those without a block heater, try inserting something in front of the radiator to partially block the air flow. Not FULLY block it, maybe 50%. And never do that with the inter-cooler. Some might say that's terrible advice, but I drove a car through the Rockies with what later turned out to be a clogged radiator in August during a heat wave (cooling systems tend to be over built so that they can handle cruising speeds up the side of tall mountains with full trailer cargo in tow). 50% blockage in -30C is probably still too permissive.
I use a timer for the block heater...it only takes 2 hrs for engine block to be at optimal temp so I leave at 730am and my timer for block heater turns on at 530am therefore not wasting as much electricity even when left plugged in over night...
 
I use a timer for the block heater...it only takes 2 hrs for engine block to be at optimal temp so I leave at 730am and my timer for block heater turns on at 530am therefore not wasting as much electricity even when left plugged in over night...
Yes, that is a good idea, and I have considered that in the past. You could also cycle the power on/off, which can also save power.
 
Hi everyone! I have a hack to solve this problem potentially. I did some Googling to see if I could resolve this with a fix but a hack will have to do for now it seems:

Back story: taking back roads to a highway is my commute. I noticed a pattern when my 2018 CX-9 heat INSTANTLY got hot only when I pressed on the gas hard to merge onto the highway! When coming home today after this revelation, I stopped at a stop light and low and behold, the heat got cold again. I quick threw the car in park, revv'd the engine and... you guessed it... the heat instantly got hot again! Like really hot!

I'm going to try it tomorrow morning when heating the car and Rev the engine a bit to see if the car gets warm. The engine must need some gas to get the heat going.

Btw those who don't experience this are not crazy. I have had my CX9 for a couple years now and this was never a problem for me either. There must be a way to fix this since older CX-9's are just prone to it.

James from NJ
 
Hi everyone! I have a hack to solve this problem potentially. I did some Googling to see if I could resolve this with a fix but a hack will have to do for now it seems:

Back story: taking back roads to a highway is my commute. I noticed a pattern when my 2018 CX-9 heat INSTANTLY got hot only when I pressed on the gas hard to merge onto the highway! When coming home today after this revelation, I stopped at a stop light and low and behold, the heat got cold again. I quick threw the car in park, revv'd the engine and... you guessed it... the heat instantly got hot again! Like really hot!

I'm going to try it tomorrow morning when heating the car and Rev the engine a bit to see if the car gets warm. The engine must need some gas to get the heat going.

Btw those who don't experience this are not crazy. I have had my CX9 for a couple years now and this was never a problem for me either. There must be a way to fix this since older CX-9's are just prone to it.

James from NJ

I would not recommend revving a cold engine hard. Perfectly fine to do this once the engine has warmed up, but not as a means to warm the engine or cabin right after a cold start. You could potentially cause some wear damage from revving the engine while cold.
 
What is needed to put an electric engine water jacket heater on these cars? That's the right way to pre-warm the engine. The comment above about the timer to save electricity is a very good one.

The general rule holds, as soon as the cold car will drive smoothly, drive it easy. That is the right way to warm the whole drivetrain.

There are already shutters in front of the radiator that stops air flow when it isn't needed while driving. I don't know if the shutters close when the cold car is running in Park. In any case the electric fan isn't running nor is the car's motion pushing air through the radiator and around the engine.
 
I have a 2016 CX-9 signature. I have noticed that during the winter, no matter how long I let my car warm up, it doesn't get really warm until I drive the vehicle. I let my car warm up for 45 minutes yesterday and the car was slightly comfortable when I got in it (slightly warme) and I had it set at 84. As soon as I started driving, it started warming up substantially more. I then noticed when I get to a stop light, the air is barely warm and when I start driving again the heat comes out with more power and is much hotter.

This is extremely frustrating living in upstate New York. We have three other vehicles including a Subaru SUV, Acura MDX and Toyota RAV4. Each of these cars get so warm after warming up in the driveway for 15 minutes we have to turn the heat down. With the CX-9, I keep it at 84 while it is warming up and almost for the entire time I'm driving. I have never had a car where my foot had to be on the accelerator to get really warm air out of the vents. Is anybody else experiencing this?
letting a vehicle idle for 45 minutes to let it "warm up." horrendous. Never do this. This explains perfectly how the way to actually "warm up" the vehicle, is by driving it. These engines employ some brilliant technology which ensures efficient combustion. One of such features would be the relatively cooler running temperatures.
 

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