Engine
What is a Throttle Body?
The valve that decides how much air the engine gets.
Simplified animation — not to scale.
In plain English
A metal housing between the air filter and the engine containing a butterfly valve. When you press the accelerator, this valve opens to let more air in.
A simple analogy
"It is the tap controlling the engine's air supply — the further you push the pedal, the more the tap opens."
How it works
Pressing the pedal sends a signal to the throttle body to open the butterfly valve. More air means the ECU also adds more fuel, so the engine makes more power. Carbon build-up can stop it closing smoothly.
Signs of trouble
- ⚠Hesitation or lurching when pulling away
- ⚠Erratic or hunting idle speed
- ⚠Stalling at junctions
- ⚠Check engine light related to throttle position
Rough UK cost
£150–£550
Parts: £80–£300
Labour: £60–£150 (clean) or £100–£250 (replace)
Always get a written quote. Prices vary by car, region, and parts brand.
Heads up: Carautonomy is for general guidance only. If your car is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.