Direct-injection petrol
Volkswagen TSI
From £299*
- Golf, Polo, Tiguan, GTI and R
- Intake ports and valves cleaned
- Inlet manifold gaskets and seals renewed
Engine walnut blasting · Wimborne, Dorset
Engine walnut blasting
Regain power, better economy and smoother running by clearing the carbon from your engine's intake valves.
Regain power · better economy · smoother running
Let your engine breathe as it was designed to
Engine walnut blasting is a great way to keep your engine breathing as it was designed to. Modern engines, and direct-injection petrol engines in particular, build up carbon in the intake manifold and on the intake valves. As the deposits grow, the engine is starved of air, and performance and economy suffer.
Walnut blasting uses a specialist machine to blast finely crushed walnut shells at the deposits. It removes the carbon without damaging the engine and in an environmentally friendly way, with no harsh chemicals. Done in time, it can save you money on future repairs, improve reliability and restore lost power and economy.
Carbon build-up is most common on direct-injection petrol engines, so we often recommend walnut blasting alongside Audi servicing, VW servicing, BMW servicing and Mercedes servicing. If your engine is misfiring or down on power, vehicle diagnostics will confirm whether carbon is the cause first.
Walnut blasting prices
Walnut blasting prices
Including RS models
Audi TFSI
From £299*
- A3 to A6, Q models, RS3, RS4, RS5, RS6 and RS7
- Intake ports and valves cleaned
- Inlet manifold gaskets and seals renewed
Direct-injection petrol
BMW
From £299*
- Direct-injection petrol engines across the range
- Intake ports and valves cleaned
- Inlet manifold gaskets and seals renewed
Direct-injection petrol
Mercedes-Benz
From £299*
- Direct-injection petrol engines across the range
- Intake ports and valves cleaned
- Inlet manifold gaskets and seals renewed
Direct-injection petrol
Volvo
From £299*
- Direct-injection petrol engines across the range
- Intake ports and valves cleaned
- Inlet manifold gaskets and seals renewed
Commercial
Vans & commercial vehicles
From £299*
- Vans of the makes we service
- Intake ports and valves cleaned
- Inlet manifold gaskets and seals renewed
*Prices vary with the engine and how much has to come off to reach the inlet manifold. Porsche engines are priced on request. Call with your registration for an exact price.
How it works
Engine walnut blasting: the process
The carbon sits on the back of the intake valves, inside the engine. This is how we get to it and clean it safely.
- 1
Confirm carbon is the cause
Misfires and lost power have more than one cause. If you are unsure, our vehicle diagnostics will confirm whether carbon is to blame before you book the work.
- 2
Remove the inlet manifold
The inlet manifold comes off to expose the intake ports and the backs of the intake valves, where the carbon builds up.
- 3
Close the valves, one cylinder at a time
The engine is turned until both intake valves on the cylinder being cleaned are shut, so nothing can get past them into the engine.
- 4
Blast with crushed walnut shell
Our specialist machine blasts finely crushed walnut shell into the port while a vacuum draws the carbon and media straight back out. The shell is hard enough to shift carbon but softer than the metal of the valves and ports.
- 5
Vacuum and inspect every port
Each port is vacuumed clean and checked before we move to the next cylinder, so no shell or carbon is left behind.
- 6
Refit with new gaskets and seals
The manifold goes back on with new gaskets and seals, which are included in the price. Then we clear any stored faults and road test the car.
Before & after
What the carbon looks like
These are the intake ports of a car we cleaned. On the left, before: carbon caked on the valves, restricting the airflow and costing power and economy. On the right, after: the deposits removed, restoring the airflow the engine was designed for.
- Reduced engine performance
- Poor fuel economy
- Poor throttle response
- Poor engine idle
Those are the four problems carbon build-up causes over time. If your car has any of them, book it in and we'll check it over.
Signs you need it
Signs of carbon build-up
Carbon builds slowly, so the symptoms creep up. If you recognise any of these, walnut blasting may be the answer.
Rough or lumpy idle
Uneven carbon on the valves upsets the airflow into each cylinder, so the engine shakes or hunts at tickover, often worse when cold.
Misfires & engine light
Heavy deposits can cause misfires, a flashing or steady engine management light and misfire codes on one or more cylinders.
Poor throttle response
Hesitation or a flat spot when you press the accelerator, as the engine struggles to draw in the air it needs.
Loss of power
The car feels slower than it used to, particularly when pulling hard or overtaking. Carbon restricts the air reaching the cylinders.
Poor fuel economy
Starved of air, the engine works harder for the same result and your miles per gallon drop.
Rough cold starts
A rattly, uneven start from cold that settles as the engine warms up is a common early sign on direct-injection engines.
Engines we clean
Engines we walnut blast
- Volkswagen
- TSI direct-injection petrol engines, including GTI and R
- Audi
- TFSI engines, including the RS3 and TT RS 2.5, RS4/RS5 2.9 V6 and RS6/RS7 4.0 V8
- BMW
- Direct-injection petrol engines
- Mercedes-Benz
- Direct-injection petrol engines
- Volvo
- Direct-injection petrol engines
- Porsche
- Direct-injection engines, priced on request
- Vans
- Commercial vehicles of the makes we service
Performance owners often pair walnut blasting with ECU remapping, and many book a gearbox oil service at the same time.
Book walnut blasting
Walnut blasting across Dorset & Hampshire
Our workshop is on Woolsbridge Industrial Estate at Three Legged Cross, near Wimborne. We carry out engine walnut blasting for drivers across Wimborne, Verwood, Ringwood, Ferndown, Bournemouth, Poole, Christchurch, Salisbury, Southampton and the New Forest.
Tell us what you need using the form and we'll call or text to agree a time. Prefer to talk? Call 01202 283359.
- Wimborne
- Ferndown
- Verwood
- West Moors
- Ringwood
- Bournemouth
- Poole
- Christchurch
- New Forest
Walnut blasting FAQs
What is walnut blasting?
Walnut blasting cleans carbon off the intake ports and the backs of the intake valves by blasting finely crushed walnut shell at them with a specialist machine. It removes the carbon without taking the cylinder head off, without damaging the engine and without harsh chemicals.
Why do direct-injection engines get carbon build-up?
On older engines the fuel was sprayed into the intake port and washed over the valves, keeping them clean. Direct-injection engines spray fuel straight into the cylinder, so nothing cleans the valves. Oil vapour from the crankcase breather and exhaust gas from the EGR system bake onto them instead, and the carbon builds up over time.
How often does my engine need walnut blasting?
We recommend walnut blasting about every 40,000 miles on direct-injection engines. Some engines build up carbon faster than others, and short journeys make it worse, so if you notice the symptoms sooner, get it checked.
How much does walnut blasting cost?
Walnut blasting starts from £299 on Volkswagen, Audi, BMW, Mercedes-Benz, Volvo and vans, and that includes the inlet manifold gaskets and seals. Porsche engines are priced on request. Call with your registration for an exact price.
Is walnut blasting safe for my engine?
Yes, when it is done properly. Crushed walnut shell is softer than the metal it cleans, the valves are closed while each port is blasted, and every port is vacuumed out and checked before the manifold goes back on.
Can a fuel additive do the same job?
Not on a direct-injection engine. Fuel additives travel with the fuel, and on these engines the fuel never touches the backs of the intake valves, so the carbon stays where it is.
Do you walnut blast Audi RS engines?
Yes. That includes the 2.5 TFSI five-cylinder in the RS3, the 2.9 TFSI V6 in the RS4 and RS5 B9 and the 4.0 TFSI V8 in the RS6 and RS7. See our Audi RS and R8 servicing for the rest of what we do on Audi Sport models.
Can I have it done with a service?
Yes. Many customers book it alongside Audi servicing, VW servicing, BMW servicing or Mercedes servicing, since the car is already with us.
What our customers say
4.9Excellent · 216 Google reviewsTim SmithApril 2026 · Google review
As a nervous user of garages (due to past poor experiences), I was pleasantly surprised about the high level of service Rob Lang provided with our Mk6 Golf GTD, which wouldn't start, and was marooned on our driveway. He had it recovered to his premises within hours, and his technician diagnosed and solved several electrical problems, plus he gave it a full service and MOT (and valet). It now drives like when it was new and so will be reprieved. Rob then delivered the car to our house because we couldn't collect it for several days more. We can't thank him enough. His prices are fair and much better than a main dealer I suspect (and very importantly he kept us in the loop).
Ken HowesMarch 2026 · Google review
What a breath of fresh air! Having a problem with Audi RS6 suspension and when I called Rob Lang he booked me in same day to investigate. They identified the problem and also gave the car a good general inspection while it was up on the lift. Super friendly, very knowledgeable and I will be happy to get future routine servicing done by Langs from now on.
Tim LoganMarch 2026 · Google review
Amazing service, from start to finish the team were professional and explained everything. The knowledge and speed were second to none. Our car was fixed, serviced and unexpectedly cleaned within the timeframe quoted. They are not local to me but happy to travel for an excellent experience.
Martin OlliverMarch 2026 · Google review
Having just purchased an Iveco Daily van that had a few issues that needed to be rectified, I used an Iveco dealership who surprisingly did not completely fix the problems. I met Rob and his team of experienced engineers and was extremely impressed by their knowledge and expertise. They identified the cause of all the outstanding problems. This is a company who know what they are doing, and their customer service skills are top-notch.
Danny CoombsApril 2026 · Google review
Got my car fully serviced yesterday, and was pleased with the thorough detail and information the team gave me. Nice office, clean unit and overall welcoming experience.
Steven KingMarch 2026 · Google review
You cannot possibly go wrong by fully relying on their advice and guidance, with work that is second to none. Rob is knowledgeable and kind, with this pervading through all the staff. I was in a really tight spot with poor workmanship from another company; this was sorted out quickly and efficiently and everything made perfect. I cannot rate this company highly enough.
Colin DeanMarch 2026 · Google review
Fantastic team, top quality work at a great price - would definitely recommend.
Lorraine LloydFebruary 2026 · Google review
I was recommended Langs and so glad they did. Amazing service where staff take the time to explain the work carried out. I highly recommend. Thank you Langs for a great experience.
Lisa HarlandMarch 2026 · Google review
Thanks so much for repairing my car Rob. Always first class service and know my car is in the best hands with you and the team there - would highly recommend.
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