2024 Mazda3 Running Cold…Thoughts?

[BOUTH2O]

I need some input before my head explodes.

Situation: Bought my 3 in December. It is the fourth 3 I've had in the past 12 years. Until three years ago I lived in Upstate New York. I now live in Central Florida.
We get some pretty chilly mornings here. 35 - 40 degrees has not been uncommon this year. I have a 25 minute drive to work. Most of the drive is at 50 - 55 mph.
The damn coolant just won't come up to temp. All the info I can find says coolant temp should be between 190 and 220 degrees. My coolant is 160 (as measured by my OBDII code reader) by the time I get to work. A recent three hour, 75mph run down the Florida Turnpike got the temp up to 170.

If I let it idle for an hour temp will slowly creep up to 180. Louvers in front of radiator don't open. Fan doesn't come on.. Turning the heat on drops it down to 170 in a couple of minutes.

None of my other 3's have behaved like this. Needle always shot up to just below the half way point on the gauge within four or five miles and never moved at all.

Two dealerships have told me there is nothing wrong.

Thoughts?

 

[edmaz]

The most obvious culprit is a bad coolant control valve, which are failing at epidemic proportions on NA/CD engines. However, I'm aware of another M3 owner (earlier MY) who had the exact same problem that you described, and couldn't get it resolved, even after the CCV was replaced twice. He ended up trading for another vehicle.

In any case, the ECT numbers that you posted are not in any way normal, and they know it. So take it back in, tell them you believe your vehicle has a bad coolant control valve, and ask them to have a tech monitor and compare to the coolant temp range specified in the FSM. If they don't want to cooperate, then open a case with Mazda Corporate about this issue with your vehicle. Just keep hammering at them that the temps are way too low, and that running that way will ultimately damage the engine.

 

[GTEyes]

I think you've made a pretty strong case that something isn't right. Having the coolant temps is a clear indication.
I agree with @edmaz, sounds like the car is pushing coolant through the rad all the time.

 

[Snorting2.5]

Normal. I do logging on the Skyactiv 2.5 All the time.

Oil temp is more important to assess.

 

[edmaz]

Normal. I do logging on the Skyactiv 2.5 All the time.

Oil temp is more important to assess.

I monitor as well, and see 195F as the consistent average ECT, and many other owners have reported that, or even slightly higher typical operating temp. The temps posted by the OP are nowhere close to that and are abnormally low. If your vehicle's temps are similar to what the OP posted, then they're too low as well.

 

[Snorting2.5]

I monitor as well, and see 195F as the consistent average ECT, and many other owners have reported that, or even slightly higher typical operating temp. The temps posted by the OP are nowhere close to that and are abnormally low. If your vehicle's temps are similar to what the OP posted, then they're too low as well.

Same here. I see around 185f.

I'll occasionally see temperatures closer to OP's, as I live in Canada, and will occasionally heat up the cabin.

It's low; not too low.

Again, oil temp is more important to consider. If it doesn't reach 80c, I'd look into it.

 

[edmaz]

Same here. I see around 185f.

I'll occasionally see temperatures closer to OP's, as I live in Canada, and will occasionally heat up the cabin.

It's low; not too low.

Again, oil temp is more important to consider. If it doesn't reach 80c, I'd look into it.

By operating temp I mean fully warmed-up, and that will typically take at least half an hour to happen. The coolant actually is heating the ATF during the entire warm-up, which means that the ATF is acting as a heat sink on the ECT. Once the ATF finally reaches its full operating temp, then the ECT will also be there as well. So any temp value captured before half an hour of driving does not represent full operating temp. And that might explain the 185F that you mentioned above. Also, on a very cold Canadian day, the full warm-up time might very well be 3/4 or even a full hour.

The OP of the thread wrote this: "A recent three hour, 75mph run down the Florida Turnpike got the temp up to 170."
170F after driving 3 hours is WAY TOO LOW. Period.

Also, there's no engine oil temp sensor installed on these Mazda engines. Engine oil temperature (OIL_TEMP) is calculated by the ECU based on engine RPM, load (throttle position), oil pump solenoid position, vehicle speed, and yes ECT (coolant temp). So OIL_TEMP is an estimated value only (and partially based on ECT), while ECT is coming directly from a temperature sensor installed on the engine. Now if you're talking about transmission temp (TFT), that's a different story because there is an ATF temp sensor installed in the transmission. If you prefer OIL_TEMP that's your choice, but I'll stick with ECT as the best representation of engine temp at any moment in time.

 

[BOUTH2O]

I really appreciate the feedback by you guys. I'll throw out a little more info for folks to chew on.

Both dealerships I took the car to gave me a loaner car for a few days. Dealer #1 gave me a brand new 3 turbo hatchback. Gauge went up to normal operating temp in about six miles and never moved from there. Dealer # 2 gave me CX30. Same thing.

The scene when I picked up my car from dealer #2 was worthy of a Twilight Zone episode. I walked up to the counter and was greeted with, "Hello sir. How are you today."

"Not good. You didn't fix my car.

This was different guy than the one who did the intake of my car. So I told him about the whole issue and said that I felt like they were pissing on my shoe and telling me that it's raining. While I was telling this guy the whole story, two techs from the back came by and joined the discussion. All three guys agreed that the car was not functioning properly!

To back up just a bit. When I first called dealer #2 I spent a half hour on the phone with the service guy explaining the issue. "No problem, sir. This is a known issue. Bring it it and we'll take care of it."

When I took it in, I sat in the waiting area for 2 1/2 hours while they checked the car out. "Sir, the car is doing exactly what you said. We're giving you a loaner car and we'll get back to you in a few days." A few days later I get a call saying there is nothing wrong with car, come pick it up.

Sorry if I'm being a little long-winded, but my frustration level is off the charts, and it's nice to vent to (mostly) sympathetic ears.

 

[edmaz]

....A few days later I get a call saying there is nothing wrong with car, come pick it up. ...

Did you ask them what temp it went up to when they were doing their diagnosis?

I had assumed your vehicle is an NA, which I shouldn't have done. So I'll ask that question now just to make sure this isn't a turbo we're talking about here.

 

[BOUTH2O]

Did you ask them what temp it went up to when they were doing their diagnosis?

I had assumed your vehicle is an NA, which I shouldn't have done. So I'll ask that question now just to make sure this isn't a turbo we're talking about here.

It is not a turbo. When I took the car in the temps were in the mid 70's. The day I picked it up was 84 degrees. The drive home was an hour on the Florida Turnpike, the a half hour on secondary roads. On the turnpike coolant reached 175. Once I hit the secondary roads (45 - 50 mph) it dropped down to 160.

 

[edmaz]

It is not a turbo. When I took the car in the temps were in the mid 70's. The day I picked it up was 84 degrees. The drive home was an hour on the Florida Turnpike, the a half hour on secondary roads. On the turnpike coolant reached 175. Once I hit the secondary roads (45 - 50 mph) it dropped down to 160.

I was actually asking about what the dealership said about the ECT temp their tech saw during the testing. Or maybe you didn't discuss that with them?

 

[BOUTH2O]

Their tech said he got a temp reading of 170. He said 170 is perfectly acceptable. I find that quite interesting as everything I have found on Mazda's own website says optimal temp is between 190 and 220.

 

[edmaz]

Their tech said he got a temp reading of 170. He said 170 is perfectly acceptable. I find that quite interesting as everything I have found on Mazda's own website says optimal temp is between 190 and 220.

One thing that might be very helpful in your situation is to take a test drive of another 2024 NA 3. If you think that both of these dealerships would refuse a request from you to test drive one, then perhaps you can find a friend (or relative who doesn't have the same last name as yours) to take a test drive and snap a picture of the reader when it hits 195 or so.

 

[GTEyes]

I really appreciate the feedback by you guys. I'll throw out a little more info for folks to chew on.

Both dealerships I took the car to gave me a loaner car for a few days. Dealer #1 gave me a brand new 3 turbo hatchback. Gauge went up to normal operating temp in about six miles and never moved from there. Dealer # 2 gave me CX30. Same thing.

The scene when I picked up my car from dealer #2 was worthy of a Twilight Zone episode. I walked up to the counter and was greeted with, "Hello sir. How are you today."

"Not good. You didn't fix my car.

This was different guy than the one who did the intake of my car. So I told him about the whole issue and said that I felt like they were pissing on my shoe and telling me that it's raining. While I was telling this guy the whole story, two techs from the back came by and joined the discussion. All three guys agreed that the car was not functioning properly!

To back up just a bit. When I first called dealer #2 I spent a half hour on the phone with the service guy explaining the issue. "No problem, sir. This is a known issue. Bring it it and we'll take care of it."

When I took it in, I sat in the waiting area for 2 1/2 hours while they checked the car out. "Sir, the car is doing exactly what you said. We're giving you a loaner car and we'll get back to you in a few days." A few days later I get a call saying there is nothing wrong with car, come pick it up.

Sorry if I'm being a little long-winded, but my frustration level is off the charts, and it's nice to vent to (mostly) sympathetic ears.

I've had similar experiences with dealers. When things go wrong, they go REALLY wrong. The issue is they are taking direction from folks at Head Office on these warranty issues, which would explain how everyone at the dealer was in agreement that something isn't right...but most likely some person in another location (Mazda HO) is saying something contrary and they control the warranty money that gets to the dealer.

I feel your pain. I had a lemon of a 2018 Mazda6 and it was this song and dance at 3 different dealerships. It sucks royally and I am sorry you are having to deal with it. Trust me when I say I know it's top of mind for you all the time because we enjoy our cars and want them to operate correctly, especially if you drive it everyday and are constantly reminded of the issue.

Eventually, I got rid of it when I was in a position to trade it, which it sounds like others have done when they were in your situation.

 

[edmaz]

Their tech said he got a temp reading of 170. He said 170 is perfectly acceptable. I find that quite interesting as everything I have found on Mazda's own website says optimal temp is between 190 and 220.

In addition test driving another M3 NA (if possible), you should also open a case with Mazda Corporate on your low temp issue. Corporate will normally always try to support whatever their dealership says, but your case is based on facts, and the facts are on your side. So if Corporate tries to just brush you off on this, you can demand that they produce Mazda documentation which shows the normal range of coolant temps of a fully warmed-up vehicle. Tell them you will lawyer-up and will file a lawsuit against them, if they don't try to fix your vehicle.

 

[BOUTH2O]

I have already contacted Mazda Corporate. I emailed them about this issue on Monday, and will be following up with a phone call today. I like your tip to demand documentation and the threat to lawyer up. I am one stubborn Dutchman, and I am not going to let this go!

What is really gets my knickers in a twist is the condescending attitude of the people at the dealerships. I've been tearing engines apart and putting them back together for 50 years. In the early 80's I spent a few years working for a man who, at the time, was considered the best small displacement race engine builder in the country. In 1980 the SCCA D Production National Champion won the championship race at Road Atlanta with a Porsche 924 engine that I had built.

 

[edmaz]

I have already contacted Mazda Corporate. I emailed them about this issue on Monday, and will be following up with a phone call today. ...

Good to read that you're already active on this, but it's not clear to me if you actually have a case opened up with Mazda. I believe they only give attention to problems that have a case #, so you want to make sure to get that done, if you don't have a case opened yet.

And AFA the actual problem, I suspect the root cause with your vehicle's problem is the extremely common coolant control valve issue, as I posted previously. The specific problem is a mechanical failsafe thermostat which is supposed to only start opening at 221F. However, in the problem situations, it actually opens at a significantly lower coolant temp, which results in the engine not warming up correctly. This CCV problem has been going on for over 5 years, mainly on the CX-5, but it potentially can affect each and every NA/CD engine. Mazda has issued multiple TSBs about this problem over the years, and supposedly had fixed the problem years ago with an improved part.

However, instead of eliminating (or even improving) the problem, it's actually become MUCH more frequent on the more recent model year NA/CD engines. You can go to the parts department of either or both of these dealerships, and just say that you would like to take a look at a couple of failed factory CCVs that they have recently replaced. The parts guy will certainly be surprised by your request and might momentarily be stuck for a reply because they wouldn't have had a customer come in previously making a request like that. But they also probably won't try to deny that these valves are getting replaced regularly, and that would be your proof of the scope of this problem. I've discussed this with both parts departments in my area, and neither of them ever tried to deny or downplay how often these things are being replaced.

The last thing I'll mention is some DIY activity that you can take to try fixing this issue yourself, if all else fails. I'm glad you posted your background, because I would never even mention this stuff to a normal owner of a vehicle under warranty. I don't believe that anyone should ever mess with a warrantied vehicle, except possibly for someone who is highly capable. And you certainly appear to be in that very small group. I'm not going to bother describing that DIY activity just yet, because you would certainly want them to just replace the CCV, and hope that fixes the problem, instead of messing around with the one on your vehicle now. But keep this in mind for the future, if for whatever reason Mazda just stonewalls you, and you don't want to go the lawyer route with this (and who wants to ever do that).

 

[BOUTH2O]

Case officially opened. I should hear from the person handling my case early next week.

I just want to thank you for all your insights and help with this issue. What the hell did we do before we had the internet?

 

[GTEyes]

I just want to thank you for all your insights and help with this issue. What the hell did we do before we had the internet?

Amen!

 

[edmaz]

Case officially opened. I should hear from the person handling my case early next week.

I just want to thank you for all your insights and help with this issue. What the hell did we do before we had the internet?

People getting jerked around by a shop (particularly a dealership) is a major hot button for me, and I always try to help out someone in this position whenever I can. So I'm very glad to be able to pitch in on this one for you!

I'd like to believe that Corporate will quickly do the right thing and tell you go back to one of those dealers to get the valve swapped out. But if they try playing dumb about your problem, then rattling your saber will hopefully make them reconsider. In any case, post back how it goes with them and what they have to say about this.