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Engine stays cold

43532 Views 316 Replies 33 Participants Last post by  Majkl
I do a lot of short trips to work with my 2020 M3. The engine temp seems to not get much above the blue “cold” area unless I go on the highway. It does go up to near half when on the highway for a while but I’m just wondering if it’s normal for it to stay at 1/4 or below with city driving. Keep in mind I’m in Canada and a lot of my driving has been around -5 celcius lately.
Today was -25C, which in Fahrenheit is “frickin cold” and it stayed in “cold” area the whole trip(only 10-15 mins), but I’ll ignore today cause obviously that’s an exception and staying cold in these temps makes sense.
Thanks
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it's critical to get to the normal operating temp. it helps burn off water and fuel from the oil, and carbon deposits from the valves
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I do a lot of short trips to work with my 2020 M3. The engine temp seems to not get much above the blue “cold” area unless I go on the highway. It does go up to near half when on the highway for a while but I’m just wondering if it’s normal for it to stay at 1/4 or below with city driving. Keep in mind I’m in Canada and a lot of my driving has been around -5 celcius lately.
Today was -25C, which in Fahrenheit is “frickin cold” and it stayed in “cold” area the whole trip(only 10-15 mins), but I’ll ignore today cause obviously that’s an exception and staying cold in these temps makes sense.
Thanks
How short are your trips? My trips are usually more than 8 kilometers at the minimum and half the time I am on the highway for some of it. Last night I made a trip that was only 3 kilometers and my engine never went past 1/4 heat even though it was running for about 10 minutes. Repeatedly doing really short trips aren't great for the car battery but as long as the needle gets out of blue it's not detrimental. At these temps no matter how long you let the car warm up it won't make a difference. The new Mazda's do a sort burn cleaning process when you start the car, the process can be longer when colder. When you start you notice the engine is loud and strained with a lot of smoke coming out of the car as it's removing the moisture and cleaning carbon deposits etc. I typically wait for that process to end and the engine to settle before moving it out of park. Sometimes in order to heat the engine up faster I will start driving and once I see the needle is out of blue I will put the car in sport mode. I won't drive it aggressively because the car is still cold but sport mode keeps the RPMs up and theoretically helps it warm up faster by making it work harder. As a rule I don't go past 3k rpm when the engine is cold. If it's really cold like -25c then I will try to not even go past 2k but that's pretty hard/slow to do.
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How short are your trips? My trips are usually more than 8 kilometers at the minimum and half the time I am on the highway for some of it. Last night I made a trip that was only 3 kilometers and my engine never went past 1/4 heat even though it was running for about 10 minutes. Repeatedly doing really short trips aren't great for the car battery but as long as the needle gets out of blue it's not detrimental. At these temps no matter how long you let the car warm up it won't make a difference. The new Mazda's do a sort burn cleaning process when you start the car, the process can be longer when colder. When you start you notice the engine is loud and strained with a lot of smoke coming out of the car as it's removing the moisture and cleaning carbon deposits etc. I typically wait for that process to end and the engine to settle before moving it out of park. Sometimes in order to heat the engine up faster I will start driving and once I see the needle is out of blue I will put the car in sport mode. I won't drive it aggressively because the car is still cold but sport mode keeps the RPMs up and theoretically helps it warm up faster by making it work harder. As a rule I don't go past 3k rpm when the engine is cold. If it's really cold like -25c then I will try to not even go past 2k but that's pretty hard/slow to do.
My trip to work is only maybe 3kms, I go the long way just to put some miles on so maybe 5k. I try to get out on the highway once a week to get the engine working a bit and help out the battery. From what you said it sounds like my car is operating how it should but I was curious because previous vehicles have always gone up to about 45% temperature and stayed there. My Mazda will get there on the highway but once I get back to city driving it starts dropping down again. Putting in sport mode is a good suggestion once it’s out of cold range. I forgot I had a sport button as the car only has 600kms on it and I’m trying to be nice to it for a bit.
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Your car won't warm up fully on short trips if its really cold outside, but the coolant should at least get to normal operating temperature after about 10 minutes of driving. While its possible that you just aren't driving the car enough to do that, its equally possible that there is a problem with the temp sensor or the thermostat. I would use some sort of OBD based scanner to monitor the coolant temps that are being reported by the ECU, that should tell you something.

When you start the car with the engine cold, the fast idle sounds you hear for 20 seconds or so are part of the emissions process. The ECU changes the timing and adds a bit of extra fuel as a means to get the converter up to operating temperature faster. Its not part of any cleaning process.
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Your car won't warm up fully on short trips if its really cold outside, but the coolant should at least get to normal operating temperature after about 10 minutes of driving. While its possible that you just aren't driving the car enough to do that, its equally possible that there is a problem with the temp sensor or the thermostat. I would use some sort of OBD based scanner to monitor the coolant temps that are being reported by the ECU, that should tell you something.

When you start the car with the engine cold, the fast idle sounds you hear for 20 seconds or so are part of the emissions process. The ECU changes the timing and adds a bit of extra fuel as a means to get the converter up to operating temperature faster. Its not part of any cleaning process.
Thanks. The car definitely gets within normal operating range(above the blue) and if I take it on the highway it will go up to near half on the gauge. It could just be the short trips. My Subaru only has a blue “engine cold” light that turns off when in operating temp range so the same thing is probably happening with it, I just am not able to see.
My trip to work is only maybe 3kms, I go the long way just to put some miles on so maybe 5k. I try to get out on the highway once a week to get the engine working a bit and help out the battery. From what you said it sounds like my car is operating how it should but I was curious because previous vehicles have always gone up to about 45% temperature and stayed there. My Mazda will get there on the highway but once I get back to city driving it starts dropping down again. Putting in sport mode is a good suggestion once it’s out of cold range. I forgot I had a sport button as the car only has 600kms on it and I’m trying to be nice to it for a bit.
So tonight it was about -11°C, typical for nights here in Winter. I started the car via the phone app and went out about 10 minutes later. The car was still in blue but heater was blowing warmish air and the seat was warm. Even after 10 minutes of idling it doesn't get out of blue in these temps. However, it only takes 1 kilometer to get out of blue and the engine temp and heater get warm considerably faster. Than driving after one minute or less of idling. It still didn't reach the 1/2 mark until I hit the highway about 3 kilometers into the drive. Thankfully the heater works fine without needing the engine to reach that temperature mark. Keep being nice to the engine until 2 or 3000 I'm.
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So tonight it was about -11°C, typical for nights here in Winter. I started the car via the phone app and went out about 10 minutes later. The car was still in blue but heater was blowing warmish air and the seat was warm. Even after 10 minutes of idling it doesn't get out of blue in these temps. However, it only takes 1 kilometer to get out of blue and the engine temp and heater get warm considerably faster. Than driving after one minute or less of idling. It still didn't reach the 1/2 mark until I hit the highway about 3 kilometers into the drive. Thankfully the heater works fine without needing the engine to reach that temperature mark. Keep being nice to the engine until 2 or 3000 I'm.
if your heater is blowing warm air, the engine is warming up fine. you have a bad temperature sensor. this is about the time you should use the warranty that came with your car. highlighting to the dealer how you're getting hot air inside the car but temperature indication doesn't change should spell it out for them.

if it's anything like the previous gen you shouldn't get warm air while its still showing cold on the dash.

you could also consider a block heater while you have it in the shop. i use mine all the time in the winter and love it.
If I had that short of a drive in winter weather I would get a remote car starter and warm the car up before driving, both for comfort but mainly so the engine is operating at temps that prevent condensation in the engine and fouling the oil.

short trips are bad for internal combustion engines, most engine wear happens with cold starts.

But at least you aren't here complaining about how poor your gas mileage is for your daily driving. I imagine it is pretty bad?
if your heater is blowing warm air, the engine is warming up fine. you have a bad temperature sensor. this is about the time you should use the warranty that came with your car. highlighting to the dealer how you're getting hot air inside the car but temperature indication doesn't change should spell it out for them.

if it's anything like the previous gen you shouldn't get warm air while its still showing cold on the dash.

you could also consider a block heater while you have it in the shop. i use mine all the time in the winter and love it.
It can be stuck thermostat that is not closing properly. To OP, check the radiator or radiator hoses, if both are getting warm after engine start up. They should get warm after reaching ca. 88 celsius - middle in the gauge, when the big circuit (Engine - Radiator) should open, otherwise the "big" cooling circuit is still open, that means the engine is overcooling on Highway for example as the water is still circulating through radiator. Thermostat should regulate flow between big and small circuit to heat the engine quickly to 90c and maintain that temp.
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You can't go by the idiot gauge on the dash. Thats just there to tell you if there is a problem. The actual coolant temps need to be monitored using something like the TorquePro app, a Scanguage or some other OBD scanner that reads data generated by the ECU. Only then will you know if your coolant is up to proper temperature. The thermostat should be fully open at about 187° F.
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You can't go by the idiot gauge on the dash. Thats just there to tell you if there is a problem. The actual coolant temps need to be monitored using something like the TorquePro app, a Scanguage or some other OBD scanner that reads data generated by the ECU. Only then will you know if your coolant is up to proper temperature. The thermostat should be fully open at about 187° F.
Sure, but there is no way of getting low reading on Highway even when there is cold outside. Anything else than the "middle" is wrong and only cause of it is thermostat. It is not possible that outside temp causes engine running bellow operating temperature when everything is working as it should (thermostat ofc). About cabin heat, it is blowing "warm" Air when the temp starts rising, that is not an indication of "warm engine". I think this is clear as a day. Bad thermostat. If you ever guys had a VW or BMW, you know what I am talking about ;)
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An infrared thermometer will tell you if hot coolant is circulating through the radiator when it shouldn't be.
Nowadays, due to the engines with improved fuel efficiency, it feels like it takes forever to warm up the engine. I have a Skyactiv-X and even after all improvements Mazda has done to keep the heat inside (additional top cover for instance), it takes slightly longer than 15 minutes to warm up the engine fully, although it is not freezing cold outside, i. e. 4-5 degrees Celsius or approx. 39-41 degrees Fahrenheit (on a route where the first part is city driving up to 50 km/h speed and the second part is somewhat faster, up to 80 km/h)

Hurts when I have to make shorter trips by car...
My trip to work is only maybe 3kms, I go the long way just to put some miles on so maybe 5k. I try to get out on the highway once a week to get the engine working a bit and help out the battery. From what you said it sounds like my car is operating how it should but I was curious because previous vehicles have always gone up to about 45% temperature and stayed there. My Mazda will get there on the highway but once I get back to city driving it starts dropping down again. Putting in sport mode is a good suggestion once it’s out of cold range. I forgot I had a sport button as the car only has 600kms on it and I’m trying to be nice to it for a bit.
If you observe that the temperatures drop when you reduce the load on the engine, it may be related to the thermostat...
Normal for the 4th Gen to take a long time to heat up... bellow 0c it takes me around 15 min to get up to about middle of the gauge.. When i'm just driving in traffic around 50km/h..... If i'm on the hwy about 5min doing 100km/h with it bellow 0c outside... I know 3 other that have 4th gens and they act the same way... Nothing to worry about its normal..
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So I did a little experiment and definitely think something is wrong. I am normally more of an aggressive driver but today I drove more casually, didn't accelerate harder 2.5k rpm. I did a 12.7 km in 14 minutes. 60% of that was on the highway, went as fast as 130kmh. Engine temp gauge briefly went above 1/3 of the way and then as soon as I got off the highway it started dipping. When I parked the car and had the engine running I could watch the gauge dropping from a 1/3 to a 1/4. Took video proof and will be going to the dealership tomorrow. If it weren't for this thread and me trying to replicate the issue I probably wouldn't have noticed with my typical driving habits. Right after I parked and shut the engine off, I popped the hood and felt the hoses near the radiator. They were all cold or barely warm. I could easily rest my hand on the radiator cap and it barely felt warm.

Thanks for starting the thread Brooksy11 and Majkl plus others. I'll keep you posted on what the dealership says. I've still got a few thousand left before the factory warranty expires. Thankfully I did get an extended warranty as well but will try to get this resolved under the factory one.
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Have you tried turning off the heating and how it affects the temperature gauge? My 2019 Mazda 3 indeed takes quite a while to fully warm-up, but this process will be much faster if you turn off the heating, so that the engine does not need to share the heat with you, so to speak. If the engine temperature drops despite the fact that you turned the heating of the cabin off, there surely is something wrong.
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summation of this thread: "it's winter, I only drive a short distance, my car temp gauge isn't reaching the middle of the display"

then all sorts of theories about a new car with a stuck thermostat, or some sort of mechanical problem...

the solution: "It's cold in Canada in the winter, if you only drive a short distance (while heating the cabin), your temp gauge isn't going to hit the middle. Your short trips are also going to increase wear and tear on your engine (severe driving oil change intervals required), because if you don't regularly reach operating temps your water vapor enhanced engine oil is not going to lubricate properly all the parts that are continually exposed to condensation during your cold starts."

Definitely
worth a trip to the dealer so they can tell you that there is nothing wrong.

Next thread is inevitably going to be, "My Mazda (that I drive in the winter less than 10 miles each way to work on a cold engine) gets terrible gas mileage, not at all what is advertised..."
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Have you tried turning off the heating and how it affects the temperature gauge? My 2019 Mazda 3 indeed takes quite a while to fully warm-up, but this process will be much faster if you turn off the heating, so that the engine does not need to share the heat with you, so to speak. If the engine temperature drops despite the fact that you turned the heating of the cabin off, there surely is something wrong.

Indeed, this could be the reason...
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