Water is leaking from the muffler, but not from the tailpipe. Causes and solutions

Have you ever noticed a lump of liquid under your car, just below the muffler? Were you scared? Did you think your car was broken?

Well, most car mufflers have a small hole near the rear end; it’s called a weep hole. A weep hole is very crucial in the combustion process- it releases the excess condensed water from the combustion chamber.

If the water was left in the exhaust system, it would corrode the metal from inside.

There’s however another approach to this whole issue. If the water leak is accompanied by an unusually loud noise from your exhaust, then you should be worried.

Mufflers sometimes develop unwanted holes which result in among other things, loud exhaust systems. Such holes can be hazardous and should be repaired as soon as possible.

What Causes Holes In My Muffler?

A hole in your muffler can be caused by a myriad of factors but physical damage and corrosion are predominant.

Physical Damage

A muffler can be damaged by contact with various road hazards like potholes and speed bumps. This mainly affects high-speed driven cars. Malicious damage is also a factor to worry about- park your car in secured yards.


During the winter, there’s a lot of salt on our roads. Salt tends to increase oxidation and if not managed can lead to rust.

Is It Normal For A Muffler To Leak Water?

If the water is leaking via the factory drilled weep hole then there’s nothing to worry about.

Things can get tricky, however; if the leak is accompanied by other symptoms like loud exhaust noise and carbon monoxide particles in the cabin.

These symptoms are proof of an unwanted hole in the muffler.

Do Mufflers Have Weep Holes?

Yes, it is the channel through which condensed wastewater from the combustion process is drained.

The wastewater is a byproduct of fuel combustion. It is estimated that about one gallon of water is produced when at least a gallon of fuel is burned.

The water is initially in gas form and leaves the system via the exhaust system. If it does not get to the tailpipe and condenses due to the cool temperatures in some areas of the exhaust system, it is collected in the muffler.

When the engine ignites again, the condensed water is heated and escapes through the exhaust system as gas.

If the engine does not heat up in a long time, the water escapes through the weep hole.

Sealing the weep hole poses a risk of internal corrosion because of the wastewater stagnating on the metal.

What Happens If There’s A Hole In The Muffler?

The muffler is subjected to pretty rough working conditions and very little or no service. Over time this unfair treatment can result in one or more anomalies.

When your muffler develops a hole, there are a few things you should expect.

Effects Of Holes In The Muffler?

A Weakened Engine

When a car part gets faulty, you can expect degradation in your engine’s performance, whether mild or severe. A hole in the muffler can slowly but surely ruin your engine.

You will notice an increase in your visits to the repair shop. The issue is usually mild in the early stages but when the engine starts to misfire, it’s time to call your mechanic.

Abnormal Noise From The Exhaust System

Whenever there’s a sound problem in the exhaust system, the first culprit is usually the muffler- for all the right reasons.

The muffler is designed to mitigate noise from the engine. When it is damaged, the noise should not come as a surprise.

Carbon Monoxide Poisoning

The muffler is directly connected to the catalytic converter where all the carbon monoxide from the engine is cleaned. If there’s a hole in the muffler, poisonous gasses can easily penetrate the cabin.

If you ever smell carbon monoxide gas in your car, no matter how mild, get out immediately- this gas is harmful to persons of all ages. Some of the symptoms of a carbon monoxide attack include nausea, vomiting, and dizziness.

Is There Supposed To Be A Hole In The Muffler?

Yes, the weep hole is an important part of the muffler. Without it, the wastewater from the combustion chamber would corrode the muffler metal

How Much Does It Cost To Fix A Hole In The Muffler?

The cost depends on the repair method you choose. You can weld the muffler, apply muffler tape or just replace the entire thing.

Muffler tape is cheap, both online and in retail stores.

Welding will cost around $50 depending on the amount of time it would take and maybe the rates in your area.

You should only use muffler tape as a temporary solution. Welding and replacement are the safest options for dealing with holes in your muffler.

Can I Drive With A Hole In The Muffler?

Theoretically and practically, a hole in your muffler will not hinder you from driving your truck.

The proper question in this scenario should be: can you bear the loud noise, the carbon poisoning, and possibly the need for a new engine.

If you can, then go ahead and drive but if you value your car and want to spend less at the repair shop, don’t drive a car with a hole in the muffler.

Take Away

A hole in your muffler is normal unless the other symptoms of a damaged muffler show. Mufflers are designed to include weep holes but chemical and physical damage can add more holes.

These extra holes pose a risk to both you and your car. The cost of mending holes in the muffler is pretty low- driving with a damaged muffler is not worth it.

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