A squeaking noise in your car points to two different causes: a worn window seal or a problem with the exhaust system. Both are irritating. They each require a different approach. A squeaking window seal occurs regularly with some models. The Ford Fiesta has this problem at speeds above 120 km/h. Noises from the exhaust system also occur more often with this popular car due to corrosion and wear. Discover below what causes these noises and how best to tackle them.
Why does the window seal squeak at high speed?
A squeaking window seal is caused by friction between the rubber and the glass. At higher speeds, the airflow along the bodywork increases, causing the rubber to vibrate or whistle. This happens mainly with aged, hardened or dirty rubber. Sand, road salt and wax residues between the seal and the glass can also amplify the noise.
This problem occurs with the Ford Fiesta around the top of the windscreen. Owners report a whistling tone. It starts at speeds of 120 km/h or higher. The cause lies in a small gap or irregularity in the rubber strip. Moisture and temperature fluctuations speed up the hardening of the rubber. As a result, contact with the glass becomes less smooth.
A dry or worn seal can also lead to other problems. Think of water leaks, misted-up windows or moisture inside the car. Don’t just tackle the noise. Also check the condition of the rubber.
‘ Aggressive products can attack the rubber or dry it out even further. ’
How do you fix a squeaking window seal?
Most problems with a squeaking window seal are easy to solve. Start by thoroughly cleaning both the rubber and the glass. Use lukewarm water and a mild cleaning agent. This removes sand, dirt and car wax residues. Pay extra attention to the seams and edges where dirt easily accumulates.
Treat the rubber after cleaning with a suitable care product. Silicone-based rubber spray works well to keep the material supple. Apply the product sparingly. Wipe away excess product immediately. This prevents stains on the paintwork or glass. Aggressive products can attack the rubber or dry it out even further. Avoid these.
Also check how the rubber strip is fitted. Look to see if the strip is loose or torn anywhere. Also check whether it has been fitted incorrectly. This occurs mainly after a windscreen replacement or accident repair. Is the strip damaged? Then replacement may be necessary. A new seal does not cost much and can usually be fitted within an hour.
Specific solution for the Ford Fiesta
With the Ford Fiesta with a whistling windscreen, windscreen sealant is sometimes used. You can use this to seal small gaps or irregularities in the seal. Apply the sealant where the rubber and glass meet. Allow it to cure properly. This method is effective for speed-related noises caused by airflow.
What causes squeaking noises from the exhaust system?
A squeaking noise from the exhaust system has a completely different cause. It does not point to a problem with rubber. It indicates a leak, a loose mounting or damage to the silencer. Such noises can range from a sharp squeak to a blowing or screeching sound. The location of the defect determines the character.
Common causes are:
- A leak in the exhaust pipe due to rust or a crack
- A cracked or rusted-through silencer
- Loose brackets or worn exhaust rubbers
- Internal damage where parts inside the silencer come loose
- Corrosion at joints and welds
Exhaust noises are more audible inside the cabin in small cars. The Ford Fiesta has this characteristic. This makes even a small leak quickly annoying. Short trips also contribute to corrosion. The system does not fully warm up then. Moisture remains behind.
Recognise the signs of a faulty exhaust system
A faulty exhaust system makes itself clearly known. The noise often gets louder when you rev the engine or accelerate. With a leak you hear a blowing or screeching noise. This is especially audible on a cold start. A loose bracket can sound like a metallic rattle or ticking. Rubber can make the same noise.
Also watch out for other signs. Visible rust or black soot marks around joints indicate a leak. A smell of exhaust fumes in or around the car is another sign. Gases are then not being discharged properly. Vibrations when idling can point to the silencer. It is then damaged internally.
Some drivers confuse exhaust noises with tyre noise, brake noise or bearing noise. The moment they occur shows the difference. This often makes it easy to distinguish. An exhaust problem is most noticeable when accelerating or with a cold engine. Other noises depend on speed or steering angle.
A visual inspection helps. Look under the car for rust, cracks and loose parts. You can often see what’s going on. Pay particular attention to the joints. Also check the clamps. Furthermore, look at the brackets. Soot marks around seams indicate a leak. You will mainly see these at connections.
Also check the exhaust rubbers. These hold the exhaust in place. They dampen vibrations. Worn rubbers can come loose. The exhaust then starts to sag. It can also hit the underside of the car.
Listen to whether the noise changes when you gently press the accelerator. Does the blowing sound get louder? Then there is a leak. Note: only touch the exhaust when it is cold. The engine must be switched off. A hot exhaust causes burns. These can be serious.
‘ A badly repaired exhaust is dangerous. ’
Repair or replace the exhaust system?
Minor damage to the exhaust system can sometimes be repaired. A small leak can be welded. You can also temporarily seal it with a repair kit. Replacing a loose clamp is also simple. Replacing the rubber is just as easy and inexpensive. These types of repairs are suitable for light wear. There must not be severe corrosion.
In cases of heavy rust, large cracks or internal damage, replacement is the best option. A silencer with internal damage cannot be reliably repaired. A heavily rusted silencer is also unreliable. Replacement ensures that the exhaust discharges properly again, dampens sound and does not leak dangerous gases.
Have repairs carried out by an approved garage or specialist. Especially with leaks, it is important that the system is safe and gas-tight. A badly repaired exhaust is dangerous. Carbon monoxide can enter the car.
Maintenance tips to prevent noises
Regular maintenance prevents problems with window seals and exhaust systems. A squeaking window seal, for example, is caused by dirt or hardening. Wash the edges and seams of the windows regularly. This removes dirt and sand. Treat the rubbers several times a year with a suitable care product. This prevents drying out and hardening.
Check the exhaust system at every service. Make this a fixed part of your routine. Look at the condition of the brackets. Also check the rubbers. Furthermore, pay attention to the joints. If you notice early rust or small cracks, they are easier and cheaper to repair. Always have a car with a strange noise inspected on a lift.
Pay attention to seasonal influences. In winter the rubbers can become harder. Squeaking noises occur more often then. In summer the rubber dries out faster. This can also cause friction and noise. Regular attention helps identify small problems. This stops them getting worse and saves you from having to carry out expensive repairs.
When should you take action?
A squeaking window seal seems harmless, but can point to beginning leakage or poor fitment. Do you see moisture in the car? Or have misted-up windows? Notice water running down the A-pillar? Then an inspection is needed. It is not just about the noise. The watertightness of your car is also at stake.
A squeaking exhaust system requires quick action. Check it immediately. A leak can lead to dangerous fumes in the cabin. A loose silencer can cause damage. A loose bracket also affects the parts underneath. Notice that the noise is getting worse? Or are new symptoms appearing? Then have it checked.
‘ There is a clear explanation available for every problem. ’
Discover more about car problems
On the Carnews website you will find more information about common car problems. Think of maintenance tips and practical solutions. Are you dealing with noises, leaks or technical faults? There is a clear explanation available for every problem. You will also find useful guidelines here. Read the articles and learn more about problems, diagnosis and maintenance of your car.
Frequently asked questions
A squeaking window seal is usually not a sign of a major technical problem, but rather of dry or dirty rubber. It can often be solved yourself by thoroughly cleaning the rubbers and treating them with a suitable rubber or silicone product. If the squeak persists after cleaning and maintenance, the seal may be worn or poorly fitting and replacement is sensible. Only if there is also water ingress, draughts or windows that do not close properly, might there be more going on and a professional check is advisable.
Use a special rubber care product or rubber care stick (for example silicone- or glycerine-based) to keep the window rubbers supple and prevent them from drying out. A thin layer of silicone spray that is explicitly suitable for rubber can reduce squeaking, provided you wipe off any excess product. Avoid mineral oils, universal lubricants such as WD‑40 and aggressive cleaners, as these can actually damage the rubber.
You can recognise unusual noises from your exhaust by listening carefully to when they occur: at cold start, during acceleration or only when idling, and whether it is a whistling tone, blowing sound, rattle or loud drone. A whistling or blowing noise often points to a leak or crack in the pipe or silencer, a rattle to loose brackets, rubbers or internal damage, and a suddenly much louder exhaust to a severely leaking silencer. Look under the car for rust, cracks, loose parts and black soot marks around joints and carefully feel (only with a cold, switched-off engine) whether exhaust gas is escaping where it shouldn’t. If the noise clearly changes when you press the accelerator or quickly gets worse, have the exhaust system professionally checked on a lift.
Repairing a defective exhaust system is often cheaper and quicker, and for small leaks or loose rubbers it can be a perfectly good temporary or targeted solution. The downside is that repairs on an otherwise rusted or aged system are usually short-lived and further problems can arise later. Full replacement is more expensive, but offers more certainty, a longer service life and often better safety and emission values. The disadvantages are the higher immediate costs and sometimes a longer workshop stay.
Recommended upgrades include a sports exhaust or performance silencer with a larger diameter and freer-flowing baffling for better gas flow. Ideally, combine this with a matching manifold (headers) and a high-quality catalytic converter or sports cat, so that the entire exhaust chain is optimised. Have the system custom tuned (for example with adjusted ECU mapping) to balance power gain and the desired noise level. Always check that the chosen parts comply with the applicable legal and noise regulations.