Windscreen wipers leaving streaks: how do you stop the smearing?

If windscreen wipers smear, clean the glass first and inspect the rubber blades. Dirt film or residues on the glass can cause streaks, as can dirty, hardened or damaged blades. If a persistent line remains after thorough cleaning, a suitable replacement blade is often a better solution than another cleaner.

How can you identify the cause?

• A broad haze: The entire swept area looks smeared. Check the glass for traffic film, cleaner residue and transferred care products.
• The same narrow line every time: Inspect the corresponding part of the blade’s rubber edge. Dirt, a nick or a damaged edge may be responsible.
• Juddering or skipping: Besides dirt, possible causes include blade condition, coatings and mechanical issues. Do not diagnose the cause from the noise alone.
• Clear exterior glass, but still hazy: Check for a film on the inside of the glass too.

If visibility is poor, pull over safely and identify the cause. A small clear viewing patch is not a lasting solution.

Checking the glass and wipers

1. Park and switch off the wipers: Use the designated service position if necessary. Do not force an arm out from beneath the bonnet.
2. Remove heavy contamination: Pre-clean the glass and rinse off adhering particles.
3. Clean the glass thoroughly: Loosen the film with Glas Reiniger Pro and wipe clear with a second, dry Carbon glass towel. For the full process, see Cleaning car windows on the outside.
4. Inspect the rubber blade: Look for embedded dirt, cracks, nicks or detached sections. Start by gently wiping it with a soft towel dampened with water; follow any specific manufacturer’s instructions.
5. Test safely: Return the wipers to their correct position and test while stationary on sufficiently wet glass. Do not run them dry.

Hold a raised wiper arm securely. An arm snapping back can damage the windscreen. Do not clean rubber blades with improvised solvents or sand or recut their edges.

When do you need new wiper blades?

If the rubber edge is damaged, deformed or still leaves persistent lines despite clean glass and gentle blade cleaning, replacement makes sense. Choose the correct blades for your vehicle and fit them properly. More chemicals cannot restore a worn edge.

If the problem remains with suitable new blades, have a workshop check the arms, contact with the glass and mechanism. Increasing blade pressure yourself is not a sound repair.

Can a glass coating cause the problem?

An unsuitable, uneven or incorrectly prepared glass coating can change wiper behaviour. This is a possible connection, rather than proof in every case of juddering. Vehicle manufacturers may restrict coatings on the windscreen.

Do not simply apply another layer over the streaks. First establish the condition of the glass and wipers, and check the coating system’s instructions. Our guide to Coating car windows helps you decide.

Preventing a fresh film

Reserve clean towels for glass. Avoid transferring paint and plastic care products onto the swept area. Suitable washer fluid and adequate winter frost protection also contribute to clear visibility, but do not replace thorough glass cleaning.

Windows fogging up on the inside are a different problem from wiper film. In Car windows fogging up inside we explain the roles of moisture, ventilation and dirty glass.

Frequently asked questions