Car Overheats in Traffic but Not on the Highway: Causes
Overheating only in slow traffic points to airflow or the fan. A Cranbourne West specialist explains.
What it usually means
If the temperature climbs in stop-start traffic but is fine at highway speed, the cooling system can’t move enough air at low speed — usually a failing radiator cooling fan (or its relay/sensor), a partially blocked radiator, or low coolant. At speed, natural airflow masks the problem.
The pattern — hot in traffic, fine moving — points strongly to the fan or airflow.
What you should do
Get it checked promptly — overheating damages engines fast, and a fan fault won’t fix itself.
We test the cooling fan, relay and sensor, check the radiator and coolant, and pressure-test the system.
How we find & fix it
Because the same symptom can have several causes, we use dealer-level diagnostics and a methodical check to pinpoint the real cause — rather than throwing parts at it.
You get a clear explanation and a fixed written quote before any work. Book online in 60 seconds or call 03 8782 0711.
Car Overheats in Traffic but Not on the Highway: Causes — FAQ
The cooling fan or airflow can’t cope at low speed — usually a failing fan, relay/sensor, a blocked radiator, or low coolant.
Often — the fan does the cooling when you’re not moving. We test it.
No — overheating damages engines fast. Get it checked promptly.
We test the fan, relay and sensor, check the radiator/coolant, and pressure-test.
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Car doing something odd?
Trusted Cranbourne West car specialists — RACV-accredited, fixed written pricing. Book online or call 03 8782 0711.