How much does it cost to replace a car exhaust?

How much does it cost to replace an exhaust in the UK

More often than not, it’s pretty easy to tell if it’s time for a replacement exhaust system or any of its associated components. Your car will be making much more noise than normal—and often, embarrassingly so.

But what does this mean for drivers? There are a range of questions you might be asking yourself; how does your exhaust affect performance? What does an exhaust repair cost? And which of the many replacement exhaust parts will you need?

We’ve got all of the answers right here, so stop worrying about your exhaust blowing, rattling and rusting. We’ll let you know all the facts and what to expect from a replacement exhaust quote.

Reasons your exhaust system could need replacing

Mounted underneath your car, your exhaust system is constantly exposed to the poor weather elements that are likely to cause your exhaust pipe, manifold, silencer and any of the fixings that hold it onto your car to corrode. If you notice big chunks of rust dropping off any of the components, or you hear excessively loud noises coming from below, then chances are one or more of your parts has worn out and it’s time to take care of that exhaust pipe repair.

What does your exhaust do?

Your exhaust system is made of a collection of components; each of which is subject to wear and tear and eventual failure.

  • Exhaust manifold
  • Downpipe
  • Exhaust pipes
  • Exhaust silencer (this is often called the ‘back box’)
  • Catalytic converter

This system of pipes and parts, channel the exhaust gases from your engine, back into the atmosphere. The pipes and parts are connected to each other using exhaust gaskets. They’re fixed to your car using various exhaust mountings, many of which are made of rubber.

Typical causes of exhaust failure

As well as the constant abuse by the British weather—mostly the rain and snow kicked up from the road—there are many other contributors to your exhaust system malfunctioning. Given the high temperatures of the fumes leaving your engine, it means that your exhaust manifold is subject to extreme heat. Your manifold will cool down again once your engine stops running. It’s these extremes of temperature variation that can cause cracks in your manifold to appear over years of continuous use. Leaky engines dripping oil, coolant or other liquids and fluids on the exhaust system can accelerate wear and corrosion. The constant vibration and movement of your exhaust components will wear out the fixings and gaskets over time. That overtly loud blowing noise might be coming from a poor connection or a hole. Or that scraping beneath your car could be where a rubber mount has snapped or perished, dragging your back box behind you.

Catalytic converters and toxic gases

An important part of the exhaust system is your catalytic converter. The gases created by your engine are toxic, and these harmful emissions are controlled and reduced by the catalytic converter before they reach the air outside your car. If for any reason, your catalytic converter fails or malfunctions, you could be in danger of your car being flooded with carbon monoxide. So, it’s imperative to have a fully operational exhaust system at all times.

Replacing your exhaust manifold

The exhaust manifold is the first part of the system that the waste gases meet. They can reach temperatures between 1100 and 1200°F under normal running conditions. Diesel cars have a much wider range from between 700°F when idle to 850–900°F under moderate loads.

How to replace an exhaust manifold

A mechanic should check any signs of damage or malfunction, and wherever necessary, repair or replacement should be carried out to maintain the correct running of your vehicle. It’s a fairly simple process of replacing like for like, so not the hardest task for home mechanics. Just be sure to allow the engine sufficient time to cool down and to make sure all gaskets are replaced too.

Replacing your exhaust silencer

Your silencer (or back box) is designed to reduce the noise made by your car when expelling all of those waste gases. Again—due to its position—corrosion and wear are common. If you spot any obvious signs that it’s not performing as it should, then it’s time to consult a specialist.

Replacing your exhaust pipes

Larger cars will have a selection of pipes completing the exhaust process. Spotting where those problem sounds are coming from when there’s more than the basic setup to inspect, can be problematic. These larger model vehicles will have a down pipe, a centre pipe, and a rear pipe, as well as the silencer and manifold. If the leak isn’t from one of the pipes but a connection between any one of them, then it could wise to get a mechanic to take a look. They can track down exactly where the problem—or problems—are located. Our Fixter garages all incorporate expert mechanics with extensive experience. They are adept in locating precisely these types of issue to ensure satisfaction and confidence for all of our customers.

How to fix exhaust pipe leaks and holes

Why not try a DIY exhaust repair kit?

For minor repairs, most hands-on motorists will be able to make a perfectly satisfactory job of reattaching an exhaust that has been the victim of scraping a speed hump, bottoming out at the lowest part of a hill or by accidentally flying over a humpback bridge a little too fast. For smaller holes or wear in otherwise good condition exhaust pipes, an exhaust repair kit could be just the job to take care of those exhaust leak repairs. You’ll find plenty of repair putty, paste and tapes to patch up those holes and small cracks from any suitable motoring outlet.

How to unclog an exhaust pipe

The most likely part of the exhaust system to get clogged is your catalytic converter. You can buy an additive that can help to flush and clean your cat. It’s an inexpensive liquid that you add to your petrol. For around £10 it’s worth a try. It’s one of the very answers when you’re asking how to clear a clogged exhaust.

How to clean exhaust filter

In diesel cars, you’ll also have a DPF—a diesel particulate filter. The DPF captures exhaust soot to reduce your vehicle emissions and the DPF’s job is to burn off the excess to continue operating at its optimum efficiency.

You should be sure you are legally allowed to clean your filter. With many types, because they control emissions, it is illegal to take them apart. Some filters will clean themselves; some will require a change in driving style to burn off any excess. Some will simply need replacing.

So, how much does a new exhaust cost?

If you’ve got an exhaust failure or leak to repair, the vehicle you drive will, of course, have an impact on the likely costs and quotes you can expect to receive.

You might not need a full exhaust system, so you could be asking, “How much is a new exhaust manifold?” or “How much to replace my exhaust back box?” It’s worth finding out if the damaged parts can be replaced independently before you replace the whole thing.

For a full exhaust inspection, repair and replacement, you could expect to pay anything around £300 for smaller, simpler cars such as a Dacia, Daewoo or a Kia.

Bigger family cars from Ford, Hyundai, Peugeot or Vauxhall, are often around the £300–400 mark.

Luxury marques and bigger models from BMW, Alfa Romeo, Lexus or Land Rover will reach around the £600 range.