Cooling Fans - When should they operate?

A

altaski

Member
My CX7 has 42k miles. have towed a 1800lb seadoo trailer for at least 34k miles of that, in 80-105 degree temps, AC on, all with no problems.
Then a month ago, in 76 degree weather, when I stopped after a fairly flat drive pulling the trailer, like I have done numerous times in the past, and turned engine off, it started to smell like something burning. So I turned the key on and the temp gauge was pegged to HOT-248 deg, I started the engine and it dropped to normal-200 deg.
This past weekend I tested it with a scanner under the same conditions. What I found was the cooling fans work fine while driving or at idle. But when the key is in on position with engine off or off completly, the fans are not running at all.
Are they supposed to come on then or not? That is the question. It's the only thing I can think of why suddenly its getting to hot.
 
My 2007 fans continue to run after I turn the motor off. I would look to the tempeture sensor as the fault but, check the fan fuses & relay first. Make sure the fan electrical connections are tight. You are out of warrenty at 42K so try to DIY if possible.
 
Fans Sensor

So the sensor could make the fans operate normally while engine is running and not properly when engine is off?
 
Cooling fans

I took my car to the dealership and told them all of the above in prev post. They Said all is normal but when I asked how they tested it they said they did it with the engine running! How ()*&*&%&^$^&^!
I repeatedly said it was when the engine was OFF that the fans did not run, when at 248 degrees, or even 220. It should run above 213!

So my question is How to reach the Northwest Regional Rep? Mazda is very secretive in this area. What do they have to hide?
 
Cooling Fans

Mazda told my dealership Monday that there is a secondary system that operates the fans when the engine and key are off. They said it has a sensor in the radiator. They say this secondary system is seperate from the coolant temp sensor and fan modules.
I have a factory repair manual and the factory wiring diagram manual, and cannot find this secondary system in either. Anyone know how to find it in there?
 
Cooling Fans update

The dealer called back again and said that they have tried to check this secondary system but cannot find it, and there is no sensor in the radiator. Mazda is giving them contradictory information. So now they don't know what to do until a higher up engineer calls back.
 
Senior engineer at Mazda now says- FAns are NOT supposed to come on when engine is off. Even if temp gauge is pegged to highest hot it can go (while engine off but key on) which is 248 degrees+.

So now what do I do? anything?
 
Time to Sell

You may want to consider selling the 7 and getting a new one, I was just looking at some of the buying and paid experiences over on Edmunds and I was astounded at the prices some buyers are paying over 7k under invoice ! 5.5 - 7.2 was the range. Lots of good info to read
 
My CX7 fans run after the engine is shut off and the key is removed. The fans will run up to 2 minutes during which time the engine cools. My Subaru and Volvo operated the same way. I din't try it with the engine off and the key in the ignition. If your fans run a short while after the engine is off and key removed, I see no problem. Is that difficult to test or what?
 
altaski said:
Senior engineer at Mazda now says- FAns are NOT supposed to come on when engine is off. Even if temp gauge is pegged to highest hot it can go (while engine off but key on) which is 248 degrees+.

So now what do I do? anything?
Click to expand...

Sounds like you have all the ammunition you need to press your case at that dealership. I'm guessing you're out of warranty now, so any repairs come out of your pocket. Assuming that the sensor and/or fan is indeed defective, you'll have to figure out whether or not repairs fall within your budget, whether or not it's worth the hassle or if as another forum contributor suggests, trying to sell. Considering that car values in general, have plummeted, you have a tuff decision.

Good luck to you! Let us know what happens!

Vince.
 
If you have the Mazda information in an email then take the email to the dealer. If your conversation was with a real Mazda Engineer then have him send you an email stating what you told us. Since my CX7 and two previous vehicles had fans that ran (IGN key out, during cool down, I think your information is incorrect.
 
Cooling Fans

Typing out scenario's, like email seem to loose something in between the lines.
I first stated that the fans DO NOT come on with the key off. Doesn't matter if the key is in the keyhole or not. Run position/engine off, or completly off. If engine isn't running neither do the fans, even if the temp is as high as 250 degrees and gauge is pegged to hot side.

Then we have the dealer. Trying to fix but Mazda engineers telling conflicting info to them on what to do. In the end they gave car back saying nothing is wrong. Yet the same symtoms above still present. I have not received any communication from Mazda Reps or Engineers. A person cannot contact them, they say, as they are secret.

An independant shop that is looking onto this called the dealer to see what had been done and what did the Engineers say. He found out, that the dealer said the Mazda Engineers refused to release any info on how to fix this issue as it is secret propriatary information and Mazda doesn't release that. (sad1)
That is word for word! What the F is going on here? I don't know. Just want it fixed. Makes me rather distrustful of Mazda in general. Thought they were a good car company.
P.S. There is no ill will with the dealer, or me. No yelling or anything wierd went on. These are the facts to a matter of fact service situation. The Dealer can only do what Mazda tells them, as they say.
 
Hi altaski: What is happening with the fan issue? Has anyone checked the fan relays and tempeture sensors or ?? Ed
 
Cooling Fans

The latest is, I took it to a private shop and they did some testing, and changed teh Main fan relay and the Temp sensor. Now that its so cold out I am not sure if its really fixed or not. I did hook my trailer and ran it hard up a long hill, turned it off, and the Fans Never Did come On while it was off. But then it didn't heat soak up to 250 deg and a pegged temp gauge either. It did climb to 235 degrees and then started cooling off gradually-No Fans though.

And this seems like acceptable temps.

Fans do come on and off while running. Which they did before.

I took the old parts home and tested them by the book and they fell within specifications! So not sure if I just paid alot for a parts changer or a real diagnotician.
Time will tell when warm weather returns and I go out with my trailer again!
 
Still Overheating

Yesterday I drove up a long (5mi) 5% grade, stopped, let idle for 2.5 minutes, and turned off. Came back in 5 minutes and temp gauge was pegged to the hot. Turbo was bright orange. Now this was normal driving without a trailer at 38 degress outside, and windy.

I have noticed since the trans flash and ATF change last summer that the trans shifts 1, 2, 3, 4, 5, real quick by the time your going 25mph, and when in 6th on the Hwy and you come to a hill and give it more gas, the trans does not shift down like it used to. Instead it uses the turbo alot more. If you punch it, then it will shift down.

Dealer says it shifts normal, but it is different than before the flash.

So it still overheats(bang) How am I ever going to get it fixed?
 
cooling Fans

So Mr ERHAYES,

What model cx7 do you have? Not that it makes a difference but mine is AWD grand touring and the fans DO NOT come on when the car is off. Only when the engine is running and its hot enough.


One idea that came up was I have read odd things happen to some cars these days when something is added to the electrical system, like a aftermarket stereo. I wonder if that could cause either fans not to operate when engine is off or low voltage to the fuel pump-thus lean condition? I had a new head unit put in about 4 days before I noticed this overheating thing for the first time. I did have a aftermarket head unit in before that, just it was a different one, and no problems then.
And part of that tsb on the(boom01) fuel pump is concerned with voltage to the pump being insufficent.
 
Cooling Fans

Just to let you all know.....I changed both fan modules and the fans now operate. Now if I drive up a long incline in 30 deg weather, idle for 2 min before shut off, the temp only climbs to 228. The fans do operate while in the 2 min idle period. They DO NOT operate once the key is turned off. When the temp climbs to 228 while key is off, and then turned to on position, the gauge reads in the same spot as normal driving temp which is 5 notches from the bottom. Where as before new modules, the temp gauge would be pegged to hot max.
The dealer told me they would not work on my car anymore about this issue, I think because the service manual says to check the sensor, relays, fan motors, and if all ok it must be the modules, but without a way to test them, so the dealer probably felt a $700 parts bill just to "guess" wasn't worth it so they opted to not fix it at all.
Since I had tested all the parts I figured what the heck its gotta be them, its all that's left, and it was the modules.
I will be in contact with Mazda legally to force payment.
 
cooling fans

In the end it turned out to be the fan modules. They were intermittent. Improved version with new part number available. Mazda did step up and pay me back for them. So far the company has been good to me, the dealership in Bend is another story.
 
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