Perth's Leading Independent Service & Repair Specialist

Perth 01738 622416
Guildtown 01821 640368

Your Exhaust Specialist

About your exhaust

Catalytic convertors

Diesel filters

Exhaust Problems

Alastair Reid Garages Exhaust Inspection and RepairsExhausts can fail for a number of reasons. There are a number of telltale signs of potential exhaust problems, Perth Alastair Reid Garages will be able to check and advise if further action is needed. If you notice any of the following you should have your exhaust checked.

Noises such as a rattling noise may indicate loose brackets holding the system in place. Alternatively, a roaring noise could be a potential problem with the silencer. Finally, hissing or popping could be a sign that one of the pipes is leaking.

You may also notice a change in emissions such as blue or white smoke. Blue smoke indicates a possible fault in the engine, putting burnt oil into the exhaust system. On the other hand, white smoke could be due to an internal coolant leak. In either case your vehicle will need to be examined. Make an appointment with Alastair Reid Garages for an exhaust inspection.

Smells, such as exhaust fumes in or around the vehicle may be the first sign of exhaust system leaks. Ensure you have this checked out promptly at Alastair Reid Garages in Perth to prevent further problems.

Alastair Reid Garages Exhaust Replacement and RepairsAlso, don't ignore the importance of visual appearance as the presence of rust or corrosion on the pipe as well as cracks, especially where the pipes connect. This may indicate a problem. Visit Alastair Reid Garages either in Perth or Guildtown if you have any questions or you are uncertain if further action is required.

About your exhaust

We frequently take our car for granted as it just keeps going. However, when it goes wrong, we want it sorted as soon as possible. More so with the exhaust, as more than any other part of the car, the world knows when it goes wrong. Loud noises from under the car are normally the first and only indication that all is not well with the exhaust system. So why is this so?

This is the Alastair Reid Garages quick guide to exhausts on most makes of vehicle.

Here is a little about what our exhaust systems actually do in the car. There are 4 main constituent parts of any exhaust system.

Alastair Reid Garages Exhaust ReplacementExhaust Manifold Connection

Connects the exhaust to the engine block and acts as a funnel. It collects exhaust gases from the different cylinders in the engine and guides them to a single pipe into the exhaust system. This single pipe is sometimes called the Front Pipe.

Silencer Box

The silencer is designed to absorb noise created by the engine combustion process by passing it through a series of baffles. The silencer will reduce the noise from the engine cylinders to a legal and environmentally acceptable level. The overall level of reduction and therefore the design of the silencer will vary with every model. Some vehicles have more than one silencer or have a split in the exhaust system to feed 2 silencers and tail pipes.

Catalytic Converters

Exhaust gases emitted from the engine contain harmful and poisonous gases that cause air pollution. When the gases reach the CAT they are exposed to a coating of precious metals which act as a catalyst on these gases, converting them from harmful to safe fumes. The CAT works better once it is at optimal operating temperature, before this some harmful gases may escape.

Alastair Reid Garages Catalytic Convertor Inspection and ReplacementA catalytic converter is a vehicle emissions control device that converts toxic by-products of combustion in the exhaust of an internal combustion engine to less toxic substances by way of catalysed chemical reactions. The specific reactions vary with the type of catalyst installed. Most present-day vehicles that run on gasoline are fitted with a “three way” converter, so named because it converts the three main pollutants in car exhaust: carbon monoxide, unburned hydrocarbon and oxides of nitrogen. The first two undergo catalytic combustion and the last is reduced back to nitrogen.

Tail PipeThe tail pipe is the part of the exhaust that extends from the back of the car. It allows free exit of the remaining exhaust gases into the atmosphere.

Diesel Filters

In Diesel engines the catalytic converter is replaced by a diesel particulate filter. These filters do require maintenance and can often lead to inefficient or poor running performance. Regular checks and cleaning are required. Alastair Reid will be able to advise on the best optimum performance and maintenance of your vehicle diesel filter.

Alastair Reid Garages Catalytic ConvertorsA diesel particulate filter (or DPF) is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine. Wall-flow diesel particulate filters usually remove 85% or more of the soot, and under certain conditions can attain soot removal efficiencies of close to 100%. Some filters are single-use, intended for disposal and replacement once full of accumulated ash. Others are designed to burn off the accumulated particulate either passively through the use of a catalyst or by active means such as a fuel burner which heats the filter to soot combustion temperatures; engine programming to run when the filter is full in a manner that elevates exhaust temperature or produces high amounts of NOx to oxidise the accumulated ash, or through other methods.

This is known as "filter regeneration". Cleaning is also required as part of periodic maintenance, and it must be done carefully to avoid damaging the filter. Failure of fuel injectors or turbochargers resulting in contamination of the filter with raw diesel or engine oil can also necessitate cleaning. The regeneration process occurs at road speeds higher than can generally be attained on city streets; vehicles driven exclusively at low speeds in urban traffic can require periodic trips at higher speeds to clean out the DPF.[2] If the driver ignores the warning light and waits too long to operate the vehicle above 40 miles per hour (64 km/h), the DPF may not regenerate properly, and continued operation past that point may spoil the DPF completely so it must be replaced.

Alastair Reid Garages will advise on the requirements of your diesel particulate filter, for all models. Contact 01738 622416or 01821 640368 to book an appointment.


Filters require more maintenance than catalytic converters. Ash, a by-product of oil consumption from the normal engine operation, builds up in the filter as it cannot be converted into a gas and pass through the walls of the filter. This increases the pressure before the filter. Warnings are given to the driver before filter restriction causes faults to become evident that impact on driveability or even damage to the engine. Regular filter maintenance is a necessity.

Alastair Reid Garages are able to advise on maintenance needs for diesel particulate filters on all models. Contact 01738 622416 or 01821 640368 to book an appointment.

When it comes to car fault analysis and diagnostics you want a service that will quickly and accurately diagnose the issue to ensure a swift resolution. Alastair Reid Garages is second to none with the latest state-0f-the-art diagnostic tools at your disposal supported by model specific experts.

Diagnostics »

Modern vehicles, employ complex electronics and control systems and need to be serviced right. Having access to specialist equipment is essential in ensuring optimum performance while checking all vehicle systems are operating perfect leading to trouble-free motoring for you.

Servicing »

Alastair Reid Garages are one of very few independent garages in Scotland that have invested in state-of-the-art equipment and training for our team members. Providing you with dealer level diagnostics and repairs. You can be confident that your car is repaired to the highest standard.

Repairs »

Suppliers deliver their vehicles with a software and management configuration that is a trade-off to match the performance of the vehicle across global markets. Changing the performance characteristics of your car for your particular driving needs can give economy and performance gains.

Performance »

What Our Customers Say

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Why use Alastair Reid Garages?

Member of Good Garage Scheme - customer feedback available online

Peace of mind - knowing our trained technicians have access to the latest information for your vehicle

Full range of services in Perth garage and Guildtown garage - MOT, servicing, tyres, exhausts, engineering etc.

All makes and models of vehicles serviced and repaired

The only dedicated auto electrical repair service in a Perth garage

Know your costs - no hidden charges, service costs fixed upfront

We value your business and will do everything we can to ensure you are happy with every aspect of your visit

Proven - established in Perth area for over 60 years

Understanding your needs - independent Perth garage

Delivering consistent service focused on your needs and time-scales

Quality - feel safe with our 12 months parts and labour guarantee

Consistency - we subscribe to SMTA, Motor Codes and OFT Codes of Practice

Save time - we use the latest diagnostics equipment available in the industry

Convenience - choose Perth Garage our city centre location or Guildtown, with free courtesy car

Manufacturers Warranty is protected

Save money - our fixed and repair rates save you money on main dealer prices

Visit with Confidence

You can visit Independent Alastair Reid Garages in complete confidence, knowing you will be looked after. Not only do we guarantee all of our work (parts and labour) for 12 months, we also subscribe to codes of practice. As a Bosch appointed service centre we adhere to the OFT code of conduct for garages, in addition we are members of the Scottish Motor Trade Association, Good Garage Scheme and Motor Codes, all of which give you security in the knowledge we will take care of you and your vehicle. In the unlikely event that you wish to challenge the work that Alastair Reid Garages have undertaken, then please contact the garage directly in the first instance. Should you not be happy that this issue is resolved then you can contact Motor Codes via their website, they provide dispute resolution services on behalf of Alastair Reid Garages.