Power steering heavy or uneven — where does it come from?

First: which system do you have?

With hydraulic assistance the engine drives a pump via a belt, pressurising fluid. You recognise it by a fluid reservoir under the bonnet marked for steering fluid. With electric assistance (EPS) an electric motor does the work, there is no reservoir and no belt — most cars built after roughly 2010 work this way.

Hydraulic: the classic causes

• Too little steering fluid. Usually from a leak: at the steering rack, a hose or the pump. Topping up without finding the leak is postponement.
• Groaning when turning in, especially stationary with a cold engine. The classic picture of a pump drawing air or nearing the end of its life.
• A slipping or worn belt. Squealing when turning in that stops as soon as you release the wheel.
• Contaminated fluid. Dark, burnt-smelling steering fluid attacks the valves inside the rack.

Electric (EPS): different causes

• A fault in the control unit or steering motor — often with a warning light and a car falling back to heavy steering as a fail-safe.
• Torque or steering angle sensor reading incorrectly. This produces the typical picture of assistance that works one way but not the other.
• Voltage problems. EPS draws a lot of current. A weak battery or a poor earth connection can make the assistance drop out temporarily — see strange electrical faults from a bad earth.
• After a repair or battery replacement: sometimes only a basic setting of the steering angle sensor is needed. That is minutes of work with the right equipment.

What it isn't (but looks like it)

Heavy steering is not always the assistance. Low tyre pressure makes low-speed steering noticeably heavier — check that first, it costs nothing. Seized ball joints or a binding wheel bearing can also weigh down the steering, and then you usually hear something too: see what each noise means.

Why not to leave it

Assistance that drops out occasionally is more dangerous than assistance that is gone altogether: you rely on support that suddenly isn't there, exactly when you are steering. On top of that, play or a fault in the steering is an APK rejection point.

What we do

On hydraulic systems we check level, colour and leaks and assess pump and belt. On EPS we read out the control unit and look at live values from the torque and steering angle sensors — a sensor reading off-centre shows up immediately there. Where a basic setting is enough, we carry it out; where a component has failed, you get a quote first.

We carry out this kind of work ourselves — see engine repair in Tilburg.