Frequently Asked Questions

FAQs about Engine and DPF Cleaning

Here are some frequently asked questions:

TerraClean is a North American owned brand name associated principally with a suite of equipment, utilised for decarbonising Internal Combustion engines – of all kinds. Here in the UK the services are available via a network of over 500 Approved centres & mobile technicians.

The most commonly recognised service is the preventative maintenance process which removes carbon and other lacquers which build up within your engine, thus restoring vehicle efficiency, improving MPG, reducing harmful emissions and prolonging the life of certain components.

Other services include unblocking of Exhaust Gas Recirculation system – EGR and Diesel Particulate Filters – DPF components on diesel vehicles.

The first and most important factor is that all Authorised TerraClean Service engineers have been trained by ourselves. This ranges from the standard initial training to use the equipment, but progresses through to high level diagnostic training to ensure they have a good understanding of why DPF blockages occur. We train technicians to understand how to unblock the unit and far more importantly to identify the cause of the blockage and how to resolve that problem so blockage does not simply re-occur.

TerraClean technicians utilise their knowledge to identify the best solution from the portfolio available to provide service to your vehicle, in consultation with yourself. Many of our TerraClean service centres and mobile technicians offer full vehicle service facilities so this can be done when you are having the car given its routine service. Many may already be known to you as they have been servicing vehicles for many years and simply added TerraClean with a limited range of other services and some are 100% TerraClean. All of our technicians are experienced knowledgeable vehicle technicians. The equipment is not for sale to enthusiastic amateurs.

We do not own any of the service network. They are all independent businesses which have bought the equipment from ourselves, been trained by ourselves and are provided with the authorised consumables and technical support by ourselves.


TerraClean is a unique system for cleaning. It is not just about the chemistry, TerraClean uses patented technology to clean from injectors – through the combustion process and cleans post combustion too. Thus cleaning through EGR and DPF.

Good pour in products are very capable of cleaning intake and injectors but not post combustion. This also applies to other equipment based cleaners on the market place, which claim to clean the entire system they do not employ our unique patented formulation and technology, they are principally only cleaning intake and injection not full system and all-important post combustion components including key sensors are not cleaned at all.

During a standard TerraClean service the equipment is attached to the vehicle and takes over as the fuel supply for the vehicle, using a highly refined fuel, coupled with the technology of the equipment.

We Randstad are the sole importers & distributors of TerraClean. We set Recommended Retail Prices (RRP) for a standard preventative maintenance service, which are:

Vehicles up to 2000cc at £110.00
Vehicles 2000cc and above from £130.00

Larger vehicles including trucks and buses may cost significantly more.

Note whilst we set RRP we are not legally permitted to enforce price levels for the dealers so please do confirm the cost price at the time of booking.

Services such as EGR & DPF clean and petrol induction cleans are priced by each Authorised Service centre based upon their own labour rates.

Yes, we do almost all vehicles. From a Motorcycle, Car, Van, HGV, Bus, Agricultural and Marine engines. There are a few exceptions which we can not do, but your local service centre/engineer will confirm when you arrange to book your vehicle in. We have now TerraCleaned (Jan 2018) over 100,000 vehicles including, motorcycles, family cars, sports cars, vans, trucks, buses, boats (outboard & inboard engines), jet skis, mini generators, and gen-sets, plant & machinery; excavators

We already have excellent UK coverage, but continue to develop the network to ensure we can provide a consistently high level of service across the UK. At the top of every page you will find the “ENTER POSTCODE HERE” box, simply fill in your full postcode and return – NO further details are requested to get contact information.

You will be taken to a page giving full contact details of your local centre / mobile technician and details of the services they provide. You can make direct contact with them using the link on that page.

Yes we have an application and approval system for perspective Approved TerraClean Service Centres. Please use the link on the home page and complete a very short form – in full. A member of our trade team will then make contact with you.
Yes. Most cars operating on LPG ran as petrol vehicles before conversion, and build up carbon deposits during that period. A TerraClean will remove those deposits. LPG does not create much carbon so a further service is not usually required.
Yes. Hybrid technology and vehicles which use Stop-Go systems to save fuel are inherently prone to carbon build up and will generally develop more carbon deposits than other vehicles with similar mileage.
As a general rule we say a car is due a TerraClean after about 15,000 miles. But if most mileage is done about town the service may be better done at a lower mileage, if most mileage is done at motorway speeds then less carbon will have built up and the service will be due at a slightly higher mileage.
Read this answer in conjunction with Q10. We generally say you should have your vehicle TerraCleaned every 15,000 miles.
We are the brand importers, manage the network and set Recommended Retail Prices. Individual service agents set their final price and may offer trade or multiple vehicle pricing options.
Whilst a TerraClean service is only due periodically there are things owners can do to reduce the amount of carbon which builds up. We recommend using a good quality branded fuel, cheaper fuels have a higher volume of additives and bio-fuel which increase both carbon build up and the amount of tars, gums and resins deposited. We do also have some products which can be used between TerraClean services and will help keep the vehicle operating efficiently.
We have TerraCleaned many vehicles with Nikasil (Nickel Silicon Carbinde) liners. These are found on several brands such as Jaguar, Audi & BMW & current Porsche 911s. TerraClean will not cause any damage to the Nikasil coating. We are only using a highly refined fuel, there are no harmful chemicals present .
The simple answer is “no”. A TerraClean service is using a highly refined fuel which can cause no harm to your vehicle or any of its components. A TerraClean service will remove carbon which has built up over time from your vehicle, as well as other contaminants (tars & lacquers) which build up and deteriorate the performance of your vehicle. TerraClean is not a “fix” for a problem, it is a highly effective preventative maintenance service which will help prevent problems occurring, prolong component life and improve the efficiency of your vehicle in terms of performance, fuel economy and emissions.
A standard TerraClean will clean through EGR & DPF systems if there is adequate air-flow. BUT a standard TerraClean is a preventative maintenance service, most of our dealers also own specific TerraClean tools for cleaning EGR & DPF and these can be used to unblock most units. If the unit is blocked with ASH, which no on-vehicle service can remove, all TerraClean service centres have access to a return to base service which will remove ash from the unit. What we recommend is that you always have a chat with your local TerraClean centre if you are being advised to replace your DPF unit, they are expensive and we consider that most are replaced when they can be cleaned. This is due to lack of knowledge and training. We make excellent technical training available to TerraClean technicians. We also recommend that you do not have a DPF removed permanently they are there for a reason and without the DPF your vehicle is emitting harmful particles into highly populated areas.
A standard TerraClean service does not touch the Intake on a DI engine. But there is an adaptor tool the service agent can use to clean Intake and there is a specific Petrol Induction tool which many of our agents have specifically designed to clean this part of a Direct Injection system. Simply talk to the agent when booking the car in about your requirements.

Yes, in many cases the DPF is only blocking because the owners mix of driving does not allow for the unit to go through its self-cleaning process which is called Regeneration. Including some simple routines into your driving mix can enable the unit to regenerate. Check out the link below from the RAC which we feel gives some good advice.

Also bear in mind that blockages may be due to faults with other vehicle components and regeneration may not resolve the problem, that’s when you should speak to one of our experts.

RAC Click Here

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