Possible overheating issue: Help needed

[Jaysan]

Hey guys,

So I was driving the car today on the highway and today was foggy so my windshield fogged up.
I turned the fan on and put it all the way to the right (window) and turned the AC on.
The fog went away after awhile. I wasn't really paying attention.

I parked the car for about 2-5 minutes. Turned it back on and noticed my window was again fogged, I did the same, put the air direction to the window with AC on and nothing. It kept getting foggier.

I than look around for any possible issues.....well, I turned the vent to vent towards me. AC was on, but the air was warm, not ice cold.

Than I look at my eng temp and it was hovering around 3/4 the way up!

I turned the vent on to high, and switched from cold air to hot air. Once I did that, the engine cooled down a bit. o.0

If I drive on the highway and put the air to cold, my eng temp would go up again.
It would only hover around the 1/2 mark when I had the heat on -_-.

It I stop, the heat slowly goes up.

I was able to make it home with the heat cranked high.

Once I got home, I pop the hood and see that my Rad fan is ON, but the eng temp is slowly rising....

Is this a thermostat issue?
Or something else?

Thanks for your help guys!

[Jaysan]

oh, Forgot to mention.
I drive a 2008 Mazda3 GT.

I did a quick search and people have mentioned to look at the radiator fluid level?
I will check that tomorrow morning when its bright out. Too hard now to see what the level is at. ><

[peterm15]

thermostat issue


This.
But I'm no mechanic.

[kilo4321]

If your coolant is fine I can almost guarantee you it's the thermostat. Shouldn't cost you more than 40$ plus a jug of coolant (you have to do a partial drain of your coolant when changing it out)
Are you throwing a code? If so and it's P0128 here's where to go
http://www.obd-codes.com/p0128

[gabbygenier]

I would say its the thermostat also.

but unlike most cars out there, the thermostat in the 3 also includes the housing for it so because of that, its around 90$. and you will basically need to do an engine coolant flush at the same time since youll pretty much drain most of it when you take the housing off.

[kilo4321]

I would say its the thermostat also.

but unlike most cars out there, the thermostat in the 3 also includes the housing for it so because of that, its around 90$. and you will basically need to do an engine coolant flush at the same time since youll pretty much drain most of it when you take the housing off.

wonder if thats the same for 2010+ ?? because that sucks... :bang

[Jaysan]

So I searched and found this thread:
http://www.torontomazda3.ca/forum/showthread.php?46149-Thermostat-replacement

Looks like I will try and see if its the thermostat by touching the small and large hose coming out of the thermostat.
See if its my thermostat.
Will probably call MoT to see if they have it in stock :)

[sudz]

Is there a fuse for the Rad Fan?

The Parking and having the heat turn up is an indication to me. When you park, does the Rad fan turn on?

[Jaysan]

The fan turns on right when the car is in I believe.

[kilo4321]

Thermostat!!!

[Jaysan]

I checked my small and large tube coming out of the thermostat and small one was hot, large one was luke warm/cold.
Going to call up MoT in a bit to see if I can pick it up off them later today :)

[kilo4321]

Doing the labour yourself? Or getting MoT to do it?

[Jaysan]

Doing the labour myself.

It shouldn't be too hard :)
Gonna be doing it tomorrow morning :)

[Jaysan]

So I worked on the issue over the thanksgiving weekend.
Took apart the thermostat and replaced it with a new unit tanks to MoT :)
Drained and filled with new rad fluid.
Ran the car for 15 minutes with no overheating issues. Drove the car on the highway for 10 minutes with no issues :)
Spent about 2-3 hours on this process as I was taking small breaks haha

[sudz]

"Cool!" (har har)

Glad to hear you're back up and running!

[krimsalt]

Thermostat is key. Also check to make sure the radiator fan is working... my mazda3 the fan died and caused overheating. But what YOU have is due to the thermostat or the coolant temperature sensor (i'd go after temp-sensor first)

[krimsalt]

So I worked on the issue over the thanksgiving weekend.
Took apart the thermostat and replaced it with a new unit tanks to MoT :)
Drained and filled with new rad fluid.
Ran the car for 15 minutes with no overheating issues. Drove the car on the highway for 10 minutes with no issues :)
Spent about 2-3 hours on this process as I was taking small breaks haha

Lol... nvm my above

[kilo4321]

So I worked on the issue over the thanksgiving weekend.
Took apart the thermostat and replaced it with a new unit tanks to MoT :)
Drained and filled with new rad fluid.
Ran the car for 15 minutes with no overheating issues. Drove the car on the highway for 10 minutes with no issues :)
Spent about 2-3 hours on this process as I was taking small breaks haha

Glad to see you're fixed up :)

[Flagrum_3]

Thermostat is key. Also check to make sure the radiator fan is working... my mazda3 the fan died and caused overheating. But what YOU have is due to the thermostat or the coolant temperature sensor (i'd go after temp-sensor first)

Do you have a ball park figure on the cost of a coolant temp sensor? I'm experiencing an opposite issue to the OP; as I get the code P0128, (engine not reaching optimum temperature). I was thinking it's either time for a new thermostat or the sensor is farked. Your thoughts? Have you seen this before? ...I don't want to change out the thermo if I don't have to.

_3

[coteya]

thermostat get the part from mazda!! its 110$ but its worth it i had the same issue and I bought a 60$ part from part source and 2 weeks later it melted