Hi everyone. I'm very new to the mazda scene. Just began to like the mazda 3 hatchbacks recently and purchased my first a couple days ago. It's an original owner, 2004, 280k km (170k miles) with all the service records and regular oil changes, and it runs awesome. When i bought it I had checked the oil, coolant, and all other fluids and they appeared normal. The previous owner had known and told me about the air in the cooling system and how when the vehicle was at idle, cool(er) air would come from the heater.

I suspect a headgasket issue for these reasons;
- I tried to "burp" the cooling system, was somewhat successful for 1 day - air got back into the system
- Coolant reservoir smells of exhaust
- Did a 2 minute run above idle when cold and very small amount of pressure had built up in reservoir
- Took cap off and allowed vehicle to warm up, reservoir almost overflowed (however no bubbles were visible entering the reservoir)

Something to be noted is that I drove it 3 hours home without any issues, and around town the last few days with normal engine temperatures.
It's weird because the oil has a normal consistency and the coolant looks like a proper green. The exhaust smells normal, doesn't have a very "sweet" smell.
I'll also add that the thermostat was changed 1000km ago, and the water pump was changed at 200k (120k miles), and a coolant flush was done 5000km ago.

The reason I'm posting here is to see if im missing anything - if for some reason it's not the headgasket and I'm missing something small.

On another note, I also have a CEL on with code P0106 - MAP/BARO. When the temp gauge reads 1/3 i get a tick/quiet knock near the intake manifold/air intake. Apparently this has been on for a while, so naturally the headgasket (potentially) is my main concern.

Thanks everybody! looking forward to your replies.

- Lachlan

 

So its not overheating?
Its not using or loosing coolant?
The heater blows hot ok?

What problem do you think it has?

Regarding the DTC, where in the world are you?
P0106 doesn't exist in my Australian Workshop manual. But P0107 does,MAP sensor circuit low input.

MAP sensor is located on your intake manifold next to the Variable Intake Air shutter valve actuator.

 

No I haven't had any issues with overheating even slightly. I haven't lost or used any as far as I can tell, however when I was burping the system last time I found a small puddle of coolant underneath the passenger side (Right under a/c compressor?) Its weird cause I haven't had that since.

I'm located in Canada. I'm not sure exactly what the code means but I appreciate the picture. I'll check it out tonight.

Thanks for the reply man!

 

Hi sorry to double post I'd just like to add that yes the heater works great when the vehicle is moving, its just at idle that it somewhat cools down (not very bad after I attempted to burp/bleed the system) thanks!