| Requirement | Must be true |
|---|---|
| First time owning in Australia | ✔ |
| At least 18 | ✔ |
| Individual (not company/trust) | ✔ |
| Australian citizen or permanent resident | ✔ (at least one buyer) |
| Property value | ≤ $800K (full exemption) or $800K–$1M (concessional) |
| Live in the property | Move in within 12 months + live 12 months |
A car radiator is a key part of your car’s cooling system. Its job is to stop the engine from overheating.
What it does (simple explanation)
When your engine runs, it gets very hot. The radiator:
Receives hot coolant (liquid) from the engine
Cools the coolant by passing air through thin metal fins
Sends the cooled coolant back to the engine
This cycle keeps the engine at a safe operating temperature.
Where it is
Usually at the front of the car, behind the grille
This position helps air flow cool it while driving
Main parts connected to the radiator
Coolant (antifreeze) – absorbs engine heat
Radiator hoses – carry coolant to and from the engine
Radiator fan – pulls air through when the car is stopped or slow
Thermostat – controls when coolant flows to the radiator
Why it’s important
If the radiator fails:
Engine can overheat
May cause engine damage, warped parts, or blown head gasket
Vocabs
It’s called a radiator because it radiates heat away from the engine.
The word origin
Radiate = to give off or spread heat
Radiator = something that gives off heat
The name comes from Latin radiare, meaning “to emit rays” or “shine”.
Why the name makes sense
Even though a car radiator mainly cools liquid:
Hot coolant flows through thin metal tubes
Heat spreads out into the metal fins
Air passing through carries the heat away
So the heat is released (radiated) into the air, cooling the engine.
Fun fact
Home heaters are also called radiators — they do the opposite job (warming rooms by radiating heat)
In cars, the radiator’s job is to get rid of heat, not create it
Common radiator problems
Coolant leaks
Blockage or rust inside
Overheating warning light
Sweet smell (coolant)
“Intake runner control circuit low – Bank 1” is an engine fault code (OBD-II).
Here’s what it means in plain language:
What the code means
Intake runner: Movable flaps/valves inside the intake manifold that adjust airflow into the engine to improve low-RPM torque and fuel efficiency.
Control circuit low: The engine computer (ECU) is detecting lower than expected voltage in the electrical circuit that controls the intake runner.
Bank 1 (B1): The side of the engine that contains cylinder #1.
👉 In short:
The ECU thinks the intake runner actuator on Bank 1 isn’t getting enough electrical power or signal.
Common OBD code numbers
You’ll often see this described as:
P2015
P2008
P2017
(depending on vehicle make)
Common causes
Faulty intake runner actuator / motor
Broken or loose wiring (short to ground)
Corroded or unplugged connector
Vacuum leak (if vacuum-controlled system)
Stuck intake runner flap (carbon buildup)
Rarely: ECU issue
Possible symptoms
Check Engine Light on 🚨
Poor acceleration (especially at low RPM)
Rough idle
Reduced fuel economy
Engine may feel sluggish or hesitant
(Some cars show no noticeable symptoms.)
Is it serious?
Not immediately dangerous, but:
Performance and fuel economy suffer
Ignoring it long-term can cause other intake or emissions issues
What to do next
Scan the exact code (P20xx)
Visually inspect wiring & connectors
Check if the intake runner moves freely
Test the actuator voltage
Clean carbon buildup if accessible
Repair cost (rough guide)
Wiring fix: $50–$200
Actuator replacement: $200–$600
Intake manifold replacement (worst case): $800–$2,000+
-----
Mechanic suggestions
Did you take things off in car
have to find replacement, can be pretty hard. Can have many causes/ things hard to know. Have to leave car with mechanic for 2 days or so.
car will not stop. Temperatures are kinda more important, high ones.
If happen again, will do free of charge. Give him a message. $40 for testing / diagnostic
--
----
1000 r/min on a car dashboard or manual means:
👉 1,000 revolutions per minute (RPM)
What it refers to
r/min = revolutions per minute
It shows how fast the engine crankshaft is spinning
Same thing as RPM
So:
1000 r/min = 1000 RPM
Where you see it
On the tachometer (rev counter):
Numbers are often shown as 1, 2, 3…
Each number = × 1000 r/min
Example:
Needle at 1 → 1000 RPM
Needle at 2.5 → 2500 RPM
What 1000 r/min means in real driving
Normal idle speed is usually:
600–900 RPM (engine warm)
1000 RPM:
Slightly high idle (cold engine or AC on)
Normal when warming up
Normal when lightly pressing the accelerator
Why cars use “r/min” instead of RPM
r/min is the SI unit
Used in Japanese and European manuals (Mazda, Toyota, Honda, BMW)
On your 2007 Mazda 3
Cold start idle: ~1000–1200 r/min
Warm idle: ~650–800 r/min ✔ Both are normal
It measures both — all the time the engine is running.
How RPM (r/min) works
The tachometer shows the engine’s current speed in real time, not just at start-up.
1. When you start the engine
RPM jumps up briefly (often 1000–1500 r/min)
This is a cold start fast idle
Helps warm the engine and stabilise combustion
2. While the car is running (driving)
RPM constantly changes depending on:
Accelerator pedal
Gear you’re in
Vehicle speed
Engine load (AC, uphill, passengers)
Example:
Idling at traffic lights: ~700–800 r/min
City driving: 1500–3000 r/min
Highway cruising: 2000–2500 r/min
Hard acceleration: 4000+ r/min
Important to know
If the engine is off → RPM = 0
If the engine is on → RPM is always being measured and displayed
For your Mazda 3
Seeing around:
1000–1200 r/min after cold start → normal
Dropping to ~700 r/min once warm → normal
-----
What it means on a 2007 Mazda 3
“Intake runner control circuit low – Bank 1” means:
👉 The IMRC actuator or solenoid on the intake manifold is receiving low electrical voltage, or the ECU thinks it is.
On the Mazda 3, Bank 1 = the only engine bank (it’s an inline 4-cylinder).
Engines commonly affected
2.0L MZR (BK series)
2.3L MZR
Both use a vacuum-operated intake runner system controlled by an electrical solenoid.
Common Mazda-specific causes
These are very common on this model:
1. IMRC solenoid failure (MOST COMMON)
Solenoid goes weak or shorts internally
Causes low voltage reading
Very common after 100,000 km+
2. Vacuum hose problems
Cracked, brittle, or disconnected vacuum lines
Especially near the intake manifold
3. Wiring issue at the solenoid
Oil contamination in connector
Broken wire near the plug
Corrosion
4. Intake runner stuck (carbon buildup)
Flaps stuck open or closed
ECU commands movement but sees no response
Typical symptoms
Check Engine Light 🚨
Sluggish acceleration at low RPM
Hesitation when taking off
Sometimes no noticeable symptoms at all
Most likely fault codes on Mazda 3
P2004 – Intake runner stuck open
P2006 – Intake runner stuck closed
P2008 – IMRC circuit low (very common)
P2015 – Position sensor range issue
What I’d check first (DIY-friendly)
Locate IMRC solenoid
On or near the intake manifold
Check vacuum hoses
Look for cracks or loose hoses
Unplug & inspect connector
Look for corrosion or oil
Listen for clicking
With ignition ON, solenoid should click briefly
Clear code & test drive
Repair cost (Australia estimate)
IMRC solenoid: $120–$300
Vacuum hose repair: $20–$80
Labour: $100–$250
Worst case (intake manifold): $700–$1,500 (rare)
Can you keep driving?
✔ Yes, short-term
❌ Not ideal long-term (fuel economy & performance suffer)
----
An "Intake Runner Control Circuit Low Bank 1" problem (often DTC P2009) means the engine's computer detects a voltage signal that's too low in the circuit controlling the intake manifold runner flaps on Bank 1, suggesting issues with the actuator, wiring, or sensors, leading to rough idling, poor acceleration, and reduced fuel economy, as the system can't adjust air intake for optimal performance.
What it means
Intake Manifold Runner Control (IMRC): A system with flaps inside the intake manifold that change runner length to improve torque at low RPMs and power at high RPMs.
Circuit Low: The Powertrain Control Module (PCM) sees a voltage signal lower than expected from the IMRC actuator or position sensor.
Bank 1: Refers to the side of the engine that contains cylinder #1 (important for V6, V8 engines).
Common Causes
Faulty IMRC Actuator/Motor: The motor that moves the flaps can fail or break.
Wiring Issues: Damaged, corroded, or loose wires/connectors in the circuit.
Stuck Runner Flaps: The flaps themselves can get carbon-bound and stuck, preventing movement.
Sensor Malfunction: The IMRC position sensor might be sending incorrect signals.
PCM/ECU Problem: In rare cases, the control module itself has an internal fault.
Symptoms
Check Engine Light (DTC P2009).
Rough idling or engine surging.
Hesitation or poor performance during acceleration.
Reduced fuel economy.
Engine may go into "Limp Mode".
What to Do
Diagnosis: A mechanic uses a scan tool to check live data and voltage, inspect wiring, and test the actuator.
Repair: Fixes range from cleaning carbon from flaps, repairing wiring, replacing the actuator, or sometimes replacing the entire intake manifold if the actuator isn't sold separately.
