Interior condensation crops up on many car forums at this time of year and some makes and models of car seem to be more susceptible than others. Condensation can just be the result of the difference in temperature between the inside and outside of the car’s cabin as the ambient temperature drops outside or it could indicate signs of a leak.
Keep the interior surface of windows scrupulously clean to reduce condensation build up, and keeping the car’s air con on for its dehumidifying effects can also help. Also, lowering a window slightly during the last mile of the journey helps to equalise the cabin’s interior temperature with the exterior temperature can also help reduce condensation build up, as can using some form of moisture absorbing product such as cat litter as suggested by
@uglybastard or a car-specific dehumidifier bag such as a Pingi (other brands are available). Most of the dehumidifier bags can be dried out in the microwave and then reused.
If your excessive condensation is the result of a leak, possible sources of water ingress on the mk7 / mk7.5 Golf are;
- Blocked / waterlogged pollen filter.
- Cars with sunroof; blocked sunroof drain tubes.
- Leaking door speaker seals (tends to be the rear door speaker seals).
- A/C drain tube draining into car interior.
- Deformed or damaged door / window seals.
The above are likely to result in damp carpets and carpet mats so check for dampness.
- Tailgate handle drain tube becoming detached from the rubber grommet at the bottom edge of the tailgate. The rubber grommet at the exit point of the tube can perish over time leaving the tube loose to drain into the inside of the tailgate and the water inside the tailgate can then drain into the luggage compartment.
- Damaged / perished rear light cluster seals.
- Poor seal around pressure equalisation vents / flaps behind the rear bumper.
If any of the above are the cause of a leak, tale signs will be water on the boot floor and / or in the spare wheel well.
- Poor seal between tailgate hinges and hinge mounting points above tailgate / hatch opening.
- Damaged / perished seal between roof mounted aerial and roof panel - check roof lining for water staining.
- Entry and exit points of the wiring loom from the car into the tailgate above the hatch opening. The rubber sleeving protecting the wiring can become damaged or may have worked loose at the attachment points of the sleeving to the bodywork and tailgate. Check the roof lining above at the back of the car above the luggage compartment for water staining.
The above will normally result in staining to the roof lining, damp rear seat or water in the boot / spare wheel well.
Also, any wet outer clothing, wet footwear and umbrellas that are left in the car at this time of year may cause condensation on the interior windows, so ensure such items are always removed.
