Car exhaust repair guide

Using tapes, bandages, pastes and patches, to stop your exhaust from blowing

When you consider current car exhaust prices, it can make sense to patch up those small holes and leaks around the joints.

A good quality exhaust will last much longer than it once would have. Stainless steel has replaced galvanised in most instances, to deliver a much longer lifespan.

However, if you’ve got an older car and your new exhaust quote doesn’t quite seem worth it, even when taking advantage of the low exhaust prices online, a quick patch up can offer a low-cost alternative.

We’ll talk a bit more about your replacement exhaust price later, and also whether it’s worth seeking out an exhaust garage or fitters near you.

Exhaust repair accessories

You’ll find a mass of products to patch up your leaky exhaust. The following list provides an idea of just how many:

  • Metal repair bandages – metal covers bolted in place and sealed with paste
  • Silicon repair bandages – often fitted with heat resistant foils
  • Repair pastes and putties – hard drying putties applied with a spatula
  • Exhaust straps – heat resistant rubbers straps with fixing brackets
  • Self-sealing repair tapes – silicone tapes with a self-fusing coating

If you consider these simple repair kits are all priced under £10, compared to a new exhaust cost in the UK, they’re worth a go, even if they only buy you an extra few months of use.

Preparation is key to any worthwhile exhaust repair

Whether you’re going to use a paste to smother a group of small holes or a patch to cover a bigger one, preparing the area to get the most effective seal is probably the most critical part of the job.

1. Allow the exhaust to cool

Park your car somewhere level and make sure you’ve got as good access as possible to the offending area. Putting your car up on wheel jacks is the safest option, and it will give you more room to carry out the work.

Your exhaust needs to be cold for most of the procedures. It could take a few hours for it to cool completely, so don’t be in too big a rush to get started.

2. Inspect the full length of the system for holes and cracks

If you want the exhaust to work as well as it can, you need to fix all the leaks, not just the worst-case areas.

Running the engine will give you additional clues to where the exhaust is blowing. You should be able to hear where the pipes or joints are blowing, or feel air leaking out of other suspected areas.

3. Scrub away dirt, rust and anything that will prevent your fix from making a tight seal

Use a steel-toothed brush or wire wool to remove all the dirt, rust and debris. Any corrosion should be taken back to the unaffected steel wherever possible.

If you’re using tape or a patch, make sure to scrub all the way around the pipe to guarantee close contact over the full repair.

4. Clean the area for adhesion thoroughly

Once you’ve got the dirt and debris removed, you should roughen the surface with coarse sandpaper or Scotch-Brite pads to create a good key for the adhesive.

Then, using acetone, clean the area thoroughly. You don’t want any grease or grime left on the surface to contaminate the adhesion of your putty or paste.

Using exhaust repair tape

If you’re using a self-sealing tape, wrap it around the damaged area, making sure to cover a few inches either side. Follow the manufacturer’s instructions for how to seal the tape. More often than not, it will be a matter of simply running the engine to get the exhaust to the required heat.

Using exhaust repair putty

Again, follow the manufacturer’s instructions. The putty should be liberally applied with a spatula over and around the area you’ve prepared. For areas of damage more than a few small holes, you can reinforce them with a wire screen before applying the putty.

Exhaust putty will set after 2 to 4 hours, but it won’t cure fully for around 24 hours.

Using exhaust repair bandages and straps

Some bandages, whether metal or softer silicon-based options, should come with their own fixing clamps. You can utilise an epoxy sealant where recommended, and it’s ok for a little to leak out around the edges of the repair. You need to be sure that all pinhole leaks are covered to create the best seal.

Leaking exhaust manifolds and joints

If you find air blowing out of the joints between components, it’s most likely a worn-out gasket.

Each joint has its own gasket, which can be replaced. Given the exhaust’s position, the bolts are often very dirty and difficult to remove. Due to the intense heat that they’re subject to, they are prone to fixing themselves in place, almost like a weld.

If you’re struggling with the bolts, spray them with lubricating or penetrating oil to get them moving. The oil can help to break the seal between bolt and manifold.

Once you’ve gained access to the gasket, scrape it off, and anything else you find in there, with a putty knife or similar.

Then, place your new gasket in place and tighten the bolts applying the correct torque.

Exhaust repairs and the law

The main worry with most motorists is whether or not a repair made on their exhaust will fail their MOT. I’m happy to tell you that repairs made to the exhaust pipes (not the box) that are securely mounted and free from leaks won’t affect the MOT result in the slightest.

Your exhaust repair cost estimate

A reasonable repair shouldn’t cost you more than £20. If you think it will last, then that’s a fantastic saving against even the cheapest exhaust prices.

The Fixter exhaust garage near me that I use was really helpful. I chatted a bit with them about how they operate, and they were happy to offer a repair if they thought it was the best option in that situation.

How much is a new exhaust?

A new exhaust price (fitted) can cost you between £150 and £300 depending on the type of car you drive. If you want to search out fitted exhaust prices online using Fixter’s directory, you could save yourself around 15–20% on franchise and dealer prices.

Try it now. You might be surprised at how affordable it is. It’s a simpler alternative to having to make those repairs yourself.

Your other option is to get some quotes to have those holes and blows repaired by a mechanic. Your exhaust repair cost (UK) should be considerably cheaper than a full replacement.