UPDATED: 3.15pm. Greerton firefighters don't know what caused a car being driven to Rotorua to catch fire today.

Firefighters were called at 10.09am and found a car was fully in flames when they arrived on the scene on SH36, near Taumata Road.

"One young lady was driving her car to Rotorua and she had a car behind her flashing their lights at her because there was smoke coming out of the back of her vehicle apparently," says Greerton Station Officer Neil Patrick.

"The fire starerd in engine compartment somewhere, and by the time we got there it was fairly well going."

For the Greerton crew it was straightforward, says Neil. They put a high pressure hose reel into the engine compartment and extinguished the fire pretty quickly.

The car is badly damaged.

"She parked on side of the road. Traffic stopped in both directions and waited for us to come along and put it out," says Neil.

The fire started in the engine compartment, and they don't know the cause, becasue of the damage.

Traffic was backed up in both directions for some distance.