Water from exhaust

Water from exhaust

Causes & Solutions

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In most cases, this is condensation that settles in the exhaust pipes. In principle, water leaking from the exhaust is normal and not harmful to your car. However, you should not ignore it completely. Water from the exhaust is a sign that your car is not being warmed up often enough. The water can also cause the exhaust to rust more quickly.

Contents
  1. 1) Causes of water in the exhaust
  2. 2) How does the water get into the exhaust?
  3. 3) Is water in the exhaust harmful?
  4. 4) Solution: Remove water from exhaust easily
  5. 5) Cooling water or oil in the exhaust
  6. 6) Conclusion
  7. More articles

1) Causes of water in the exhaust

The main cause of water escaping from the exhaust is the Short distance trip. As the engine cannot be warmed up during a short trip, the Exhaust system cold remain. In winter, the temperature difference is naturally greater and this also leads to stronger and more frequent water leakage.

Another cause could be a warped cylinder head or a defective cylinder head gasket. However, this defect is not condensation water, but cooling water or oilwhich comes out of the exhaust. However, this defect rarely occurs in conjunction with the symptom of water from the exhaust.
If it really isn't condensation, skip to the last chapter here "Coolant or oil in the exhaust".

Water from the exhaust is usually caused by driving short distances, the exhaust is cold and heats up.
Short trips (especially in winter) are one of the main causes

2) How does the water get into the exhaust?

When Gasoline or diesel burned in the engine this results in CO2 and water. To be precise, the burning of approx. 1 liter of gasoline about 1.2 liters of water as steam.

If your exhaust is still cold, this vapor condenses in the pipes of the exhaust system. At some point, there will be so much water in the exhaust system that it will accumulate in the back of the muffler or flows out of the exhaust pipe. However, if the exhaust is driven hot enough, the water evaporates again.

3) Is water in the exhaust harmful?

No and yes. On the other hand not harmful to the car itself, but can lead to rust in the exhaust system. Condensation is part of the combustion process. However, if water frequently comes out of your exhaust, you are driving too many short trips, especially in cold temperatures. Indirectly, it has to do with the fact that other components in the vehicle problems due to short journeys. A well-known example would be the Coking of the EGR valve for diesel vehicles.

The direct consequences of water in the exhaust mainly concern the pipes and silencers of the exhaust system itself. This water, which settles in the pipes, is also the Main reason why exhaust systems rust through. The accumulated water reacts with the other substances in the exhaust gas to form Sulphuric acidwhich attacks the exhaust.

Rusty exhaust system (silencer) caused by water in the exhaust and short distance driving
Rusted through rear silencer (muffler) caused by condensation

The rear silencers are often the hardest hit, as this is also where the most condensation is stored. The Costs for a new mid-range silencer range from approx. 180€ to 320€ depending on manufacturer and car model.

4) Solution: Remove water from exhaust easily

The water in the exhaust can be removed using two different methods. However, method 1 is strongly preferred and recommended.

Method 1: Burn out at full throttle!

Full throttle is an exaggeration, but it will help you an approx. 100km round trip on the highway to solve the problem. Due to the temperatures that arise in the pipes, the Water from the exhaust system simply burns out and evaporates. This process is definitely the most effective and only costs you a little extra fuel.

Long journeys on the highway remove water from the exhaust
A long drive on the highway causes the condensation to evaporate

Method 2: Hole in rear silencer

Attention: We only mention this method here so that we can advise you against it.

You can often find advice online, drill a 2-3 mm hole in the rear silencer to drain the water. What is forgotten, however, is that you can damaging the rear silencer and making it susceptible to rust.

In addition, the hole would only prevent liquids from collecting in the silencer. The rest of the exhaust system is still damp. For these reasons, we recommend that you to abandon this method and fall back on method 1.

5) Cooling water or oil in the exhaust

To recognize which fluid is in the exhaust, you swipe your finger once in the exhaust cover. Is your sample a little sslimy or smells of burnt oil your cylinder head gasket may be defective.

If you are not sure whether the liquid is Cooling water or condensation water then observe over a period of time your Cooling water tank. If the tank empties, it is cooling water that is entering the exhaust tract.

Check water leakage from exhaust with finger, oil, coolant, condensation water
The finger check: Check whether it could be oil/cooling water or condensation water

Regardless of whether oil or coolant - both indicate a Defect in cylinder head point out. This could be due to the following causes:

Defective cylinder head gasket (CCG)
Warped cylinder head
Valve stem seals

A defective cylinder head gasket costs around 100€the actual costs are more likely to be Hidden in the effort remove the cylinder head.

6) Conclusion

When water escapes from the exhaust, this is mostly just condensation. The condensation water is Not directly harmful to the car. However, it is a sign that you should drive long distances more often. This would also prevent premature rusting of the exhaust system and also do good for other components in the engine compartment (DPF, EGR valve, etc.).

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