Because they’re underneath our cars, exhausts can wear faster than any other component, with salt and road grime causing rapid corrosion if left unchecked.

For most of us, exhausts are the easiest part of the car to ignore because we don’t see them every day when we’re driving to work or popping to the shop. Getting down on the floor to have a nosey at the exhaust isn’t something most drivers have time to do on a regular basis, and let’s face it, most of us have bigger things to worry about!

However, ignore your car’s exhaust for too long, and trouble will start brewing — potentially leading to some nasty repair bills and a failed MOT. Here, we look at some of the consequences of a faulty exhaust system, before giving you some tips on how to repair a broken exhaust pipe with Holts innovative exhaust repair product, Gun Gum.

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The Potential Problems of a Broken Exhaust

MOT Failure

The most obvious (and annoying) problem of a broken exhaust is your car failing its MOT, and recent research shows that around 7% of MOT test failures are as a result of a faulty exhaust.

For an exhaust system to be given the all-clear by MOT testers, it must be free from serious leaks and corrosion, be securely fixed to the vehicle and have the right number of silencers for the make and model.

Common exhaust faults which can lead to MOT failure include advanced corrosion, particularly when a leak has developed; missing silencer baffles, which are used to reduce engine noise; and loose exhaust mounts, where the rubber fastenings are missing or shot.

The problem is, it can be very difficult to properly check the condition of your car’s exhaust in the driveway prior to a MOT test. That’s why it’s important to be aware of any unusual noises as you’re driving around, as this could mean your exhaust has a hole or leak you just can’t see.

Reduced Fuel Economy and Higher Emissions

Exhausts are designed to channel fumes away from the front of the car and reduce engine noise, whilst maintaining fuel efficiency. If your car’s exhaust has a leak, this will have an impact on the pressure in the exhaust system, reducing fuel economy and leading to higher emissions.

Exhausts produce six gases, three of which are toxic (carbon monoxide, nitrogen monoxide and nitrogen oxide). The system is supposed to channel these fumes away and reduce the number of harmful particles emitted from the tailpipe, so your car can run more cleanly.

If a leak develops in the exhaust close to the engine, this can have a big impact on fuel economy, and could lead to fuel wastage. So, while you might think that avoiding getting a leaky exhaust fixed is saving you money, in the long term it could cost you more due to poor fuel economy.

Damage to Other Car Parts

Over time, the fumes leaking from a cracked exhaust pipe will damage surrounding components, and could even cause a fire. When they first come out of the engine, exhaust fumes are extremely hot, but cool gradually as they reach the tailpipe at the back of the vehicle. If there’s a hole in the exhaust close to the engine, these hot gases can leak out and blow straight at other components — causing heat damage and increasing the risk of fire.

The impact leaking exhaust fumes will have on other bits and bobs beneath the car will differ depending on where the hole is located on the exhaust system. The closer the hole is to the tailpipe, the smaller the impact will be on surrounding parts.

Noxious Fumes Can Enter the Cabin

One of the most serious consequences of a leaking exhaust system is the fact that poisonous gases could find their way into the cabin — which certainly isn’t good news for those travelling inside!

If noxious fumes like carbon monoxide and nitrogen oxide seep up through the floor or enter through the air vents, they could cause illness or, in rare instances, even death for the driver and passengers.

The scary thing is, harmful exhaust fumes are odourless and colourless, so you won’t know they’re in the air until you start suffering some of the effects. Mild exposure to exhaust fumes can cause headaches, dizziness and fatigue, which could prove dangerous when you’re at the wheel. And, in extreme circumstances, prolonged exposure to high levels of carbon monoxide can cause death — making it vital that exhaust repairs are dealt with quickly.

Increased Repair Bills

The simple fact is, if you don’t deal with a broken and leaky exhaust system quickly, it will end up costing you more to repair in the long term. Most small cracks and leaks can be plugged with a product like Gun Gum Paste before they get worse, however, if you leave it too long it will grow to become an un-repairable hole, leaving you with no choice but to have the part replaced — and setting you back much more than you bargained for!

Tips for Using Holts Gun Gum

Holts Gun Gum is a DIY exhaust repair system which can be used to seal holes and cracks in a faulty exhaust system. The paste can be used with the right bandage to mend small cracks, holes and leaks in the exhaust to create an airtight seal, and because the results are permanent, you can be sure your car’s exhaust is working as it should.

Gun Gum Paste can be applied simply with either your fingers (be sure to wear protective gloves) or a spatula, and dries hard either overnight or more quickly if you run the engine to heat the exhaust — creating an effective airtight seal that lasts.

If you’re thinking of using Holts Gun Gum for the first time to repair your car exhaust, here are a few essential tips to guarantee great results:

  • Make sure you clean the area first: Removing dirt, loose debris and rust from the area directly around the crack or hole is essential to make sure the seal is airtight. If you don’t clean the area first, the product may not stick to the surface as it should.
  • Use with Holts Gun Gum accessories: For the best results when using Gun Gum, use the product with our range of wraps and bandages which are specially designed for sealing exhausts. These products are particularly useful for sealing cracks and holes on awkward areas of the exhaust system, such as bends and joins.
  • Only use after the catalytic converter: If the leak is located before the catalytic converter, Holts Gun Gum may not be as effective, because areas like the manifold simply get too hot. We’d only recommend using Gun Gum to seal cracks after the catalytic converter, when the air is much cooler.
  • Holts Firegum can be used to seal leaks around the exhaust assembly where there is a poor fit or gaskets have failed.

For more information on Gun Gum, as well as our other innovative DIY car care products, visit the Holts homepage today.