So I live in the Phoenix AZ area. My car is an 05 AT Sport. Since the temps in Phoenix get into the 100's on a regular basis, my car tends to run hot.
I have brought it to the attention of my favorite dealer and they have been unable to cure the problem. They have changed the water pump, the thermostat and the radiator. And I'm on my fourth engine.
Mazda has sent their Engineers out twice to look at the car and try to figure it out. They installed foam strips around the shrouding for the radiator ducting. Had no effect. They did find that Mazda's Premix Coolant was 60% Antifreeze and 40% water. So we changed the ratio to 70% distilled water and 30% antifreeze and installed a bottle of Waterwetter. But to this day the car still runs hot when it's over 105 degrees.
This is what it was doing yesterday when it was between 111 and 114 degrees outside. I was monitoring the coolant temp with my Accessport.

This is what I saw,,,



This pic was when I came to a stop at a traffic light, as soon as I took off from the light the temp went to 241 degrees for a about a minute.



The dealer is calling Mazda again and i will talk to them later and see what they found out.
I have the Mazmart waterpump and have not installed it yet. I was waiting to see what Mazda said about it. I don't want to burn up an engine and have them blame the waterpump, if you know what I mean.

So any ideas? I have discussed this at length with the knowledgeable people on the forum but at this point I'll take any suggestions. Other than "Don't drive the car"

 

Move to San Diego! That's what I did. Its a sticky 87 here today.

When I lived in Chandler, Warner road was gravel east of Stapley.

Mike

 

Let me ad "Move" to that list of suggestions that will not happen.

 

On a serious note, did you check the oil cooler(s) and lines. Oil is also an important equation in the cooling equation.

Mike

 

Oil cooler (1) is clean and clear. Lines appear OK. Short of disassembling the oil cooler system all is well.

 

They haven't given you a new 8 yet?? By now they should have concluded that you are their most patient and loyal customer.


R3 at half price, maybe??


Good luck Easy.

 

holy smokes EAsy!!!
the Mazmart water pump should help a little bit but I completely understand your hesitation.

Add a 2nd oil cooler.

 

Thanks DMC.
Hard to believe they can't fix this. I did settle the engine replacement matter with them. I was happy.
But why they can't solve this issue is beyond me.

Hmmmm R3,,,,, I was hoping to go another 2 years in this car before I get a new one.

 

Jedi, I bought that pump at SSX last year. I was waiting to see if what Mazda did would change anything. Of course it hasn't been hot enough until now to see if their fix worked. Obviously it didn't.
It seems the only thing we have'nt done is check the trans temps. If it is overheating then it will bring the coolant temp in the radiator up with it. AT you know. I checked it (trans pan) at MM's yesterday and it was the same as the coolant temps. 210.

 

yup, that's when I picked mine up as well. Personal delivery by Paul FTW.
I bolded part of the name because your original post has it listed as a mazsport pump.

My last Mazda (626 / AT) had 'issues' with the transmission overheating all the time. I ended up getting a transmission fluid cooling unit.

 

Fixed the first post. Sorry Paul.
I was thinking of doing that. Just disconnect the AT cooler from the radiator and install a separate cooler. But let me measure the temps again and see if that could be the problem. If I see high trans temps then I'll think about doing it.

 

if this has persisted through 4 engines then problem must be in remainder of cooling system. What about flow prob with radiator oil coolers or plumbing?

 

Erick,
I'm in the same boat. The only diffrence is mine is 10-15 degrees cooler. Oh BTW just cruising, no boosting.
That being said I know the BHR rad is making a diffrence. You or I need to install a 2nd oil cooler and verify our findings.

 

flow can be increased via the mazmart water pump BUT there's no guarantee that Mazda won't point the finger at it if this engine were to also fail. (this is the 4th engine in this car)

radiator might be problem. OEM I assume?

Have any AT owners added a 2nd oil cooler?

 

What type of oil and viscosity are you using? Maybe bump up to a higher viscosity.

Does the AT have one or two oil coolers? If it has one is it possible to install a second one?

Man, it's hot where you're at...

 

A/T = 1 oil cooler

 

As you saw yesterday, its pretty easy for me to get my temps out of control as well.
The high ambient heat and low humidity make the radiator completely ineffective.
I know my intercooler isn't helping air flow at all, but there is more to it than that.
I even hooked my washer bottle up to a set of misters and emptied the entire bottle on the rad to no avail.
At the car wash the other day, it took 30 seconds or more of direct, full-trigger spray on the rad to get the temps to fall.

At this point, the only things I can think to do are to experiment with coolant mixes. I might actually try a 50/50 mix or something closer to what Mazda delivered to you.
Completely counter-intuitive and contrary to conventional wisdom, but it is one of the few things that hasn't been tried.

 

backwards thinking??? I'm confused...

 

The radiator is new. OEM.
The problem is is that the trans cooler is in the radiator transferring more heat to the coolant.
This is one of the things Mazda goofed on with the AT. One engine oil cooler, trans cooler in radiator, diminished radiator capacity and additional heat due to trans cooler. I've been thinking about an additional engine oil cooler and seperating the trans cooler to a remote.
But the thing that bothers me about doing this is,,, Why didn't Mazda do this in the first place? Why should I have to spend extra money and time to make my car work the way it should have from the beginning?
Called the dealer today, also sent them the pics, and they are calling the Mazda Tech line to see if they have any answers. Other than the ones they already tried that didn't work.
As far as engine oil 5w-30 Castrol.

 

I have read on here that distiled water and water wetter helps(no antifreeze)less viscosity makes the water move faster. You can try this too it stops that super heated air from going into your engine and only takes a minute to do.
https://www.rx8club.com/rx-8-discussion-3/no-more-detonation-%2Amiac%2A-121249/

let us know if this helps. Good luck...

 

Yeah, we've already done that.
I ran distilled only and then distilled and Water Wetter.
Now I add about 10% antifreeze and that seemed to slow the heat-up.
That is why I'm thinking the added mass of the anti-freeze might be a good thing.

 

Don't forget to fill your tires, Easy_E1.

 

dont run just water. the water pump needs a little lube, a 70/30 blend has worked the best for us. The DEI coolant stuff works better for us than the redline.
At those temps both of your fans are on BUT the air needs a way to escape. The head of mazdaspeed north america's nephrew--he was driving for roar racing at the time---told us that the only thing they really found to work was a second oil cooler and a vented hood.Even with that in extreme climates it is marginal at best.
20w50 oil is imho opinion a must for operating in that heat range.
The heat soak on these cars happens fast and like it has been said it recovers slowly indicating not much of a margin from being totally overwhelmed.
I understand why you do not want to install the pump---it does help but i dont think it will solve the prob.
We all know what it would take to solve it and that is:
1-vented hood
2-better water pump(electric water pump would be VERY NICE)
3- 70/30 blend coolant
4- a 180 thermostat(stock one is not fully open until after 200F!) barrel type
5- a better radiator with a better shroud--our fans are good but they need turning on at 180F and a better front air entry sealing.
6- separate a/t cooler
7- additional oil cooler
THEN your temps would be under control.
As it is , when that type weather good luck man.
olddragger

 

1. remove the battery box then relocate the battery.
2. Remove the original air filter box and its under tray, replace with a CAI with extension piping that reroute the air filter to somewhere else.
3. Get a 3 layer radiator.
4. A CF hood with ventilation hole.
5. If still not enough, can add fans in front of the aircond condenser.

 

Who is doing that? We just got done saying we are running blends.

Its chemically identical.

Roar doesn't use a vented hood. In fact, they don't even use fans!


Already doing that.

Maybe.

Probably not. Even a big Meziere won't move much more water in the ranges where overheating is occuring (under load and above 4000 RPM).

Already tried that. No dice.


How about NO thermostat? Tried that. No dice.


The OE shroud is pretty well designed for the fans they are using. I tried different shrouds, different fans and a different rad. None worked as well as the OE setup.
With the AP, the fans are coming on at 180°.

Those are good ideas and might be what is hurting Easy, but its not going to be all of the problem.

We can only hope but, as you go through the list as I've annotated it - probably not.

Done. No dice.

Done. No dice.

Restricting airflow even more isn't the answer. I've done the Koyo already. I'll try the BHR.

How about no hood at all? Tried it. No dice.

Once again, restricting airflow even more is not the solution and a pusher fan is a horrible idea.

The problem is a combination of factors:

1. A thermally inefficient motor
2. Low mass of the motor itself
3. The rad is not aligned with airflow
4. Nearly zero relative humidity
5. High ambient temps
6. Constant A/C usage