BMW M4 All round Brake pad & disc replacement

We had the pleasure of having this stunning BMW F82 in for all brakes replacement. The brakes weren’t due to be replaced but the customer didn’t like the wear and corrosion to the discs. And quite rightly so they didn’t look great.

As with all our brakes replacement we thoroughly remove the corrosion build up from the hub and wheel faces to prevent brake pad pick up causing disc warping.

Along with carrier and slider cleaning, then high temp grease to the brake pads to ensure free movement for miles to come.

We look forward to seeing this motor again in the future!
(If anyone can find the issue in one of the pictures that we needed to rectify before putting the new discs on please comment. If correct you’ll receive a virtual pat on the back!)

BMW M Model Servicing


BMW 320i Engine hesitation/ jerking under acceleration… fixed

A recent BMW 320i with the B48 4 cylinder petrol turbo engine with us. Fault of hesitation/ jerking sensation under acceleration. This car had been to a garage and bmw dealer previously but unable to locate the fault.

Road tested vehicle to confirm the fault under acceleration. Fault codes showing the engine is running too lean. Which means there is too much air going into the engine (or so it thinks) to fuel expected detected by the ecu using the various sensors fitted.

A fuel tank breather valve had been fitted previously by the bmw dealer, which is a known fault on this engine, but did not resolve the fault.

Using the bmw diagnostic system makes our job much easier to locate and rectify faults but it’s not always the silver bullet.

Using the diagnostics we ran through several air to fuel mixture tests. All passed ok but this is with the car stationary in the workshop. This fault only occurs whilst the engine is under load/ acceleration on the road. We then smoke leak tested the intake system, pipes, manifold, etc. No smoke present proving the intake system is tight and no allowing any extra air into the engine. Moving onto the turbo and exhaust and no smoke/ leaks either.
With the fault not showing in the workshop we took the computer on the road with us to inspect the live data readings to see if we can see any abnormalities to locate the fault.

Air mass, intake manifold and fuel pressure sensors showing plausible readings to the specified requirements. It took a while to locate as the fault was intermittent under acceleration. But eventually we found the oxygen sensor reading would go lean the same time as the hesitation/ jerking sensation. Upto 1.81.
Unfortunately the bmw diagnostics live data readings are not easy to read when they are changing quickly. So we grabbed the Bosch diagnostic system where we can graph and record the live data to easily read our findings.

The oxygen or known as a lambda sensor is located in the exhaust, either in the manifold or after the turbo if one is fitted. The sensor does what its called and measures the amount of oxygen present in the exhaust exiting the engine. A lean condition means not enough fuel so the ecu will then injector more fuel to compensate. Then a rich condition means too much fuel, the ecu will then inject less fuel. This is constantly monitored and adjusted to try to reach lambda 1. The ‘perfect’ air to fuel ratio.

As we could see from our sensor it would intermittently spike lean at 1.81. Rather than smoothly adjusting around lambda 1.
Next was to test the sensor & wiring directly, as an oxygen heater fault was also stored previously. All circuit tests passed ok. With the sensor removed we could visually see the engine/ exhaust gas is in a lean condition, with the sensor tip being white in colour.

With all other systems tested without fault to cause a lean condition. We suspected the sensor had an intermittent internal fault.
With the oxygen sensor replaced, vehicle software level updated & adaptations reset. We road tested the vehicle and it now drives as it should.
Tried. Tested. Fixed.

Fault Investigation – Diagnosis


A truly green battery

“With the Neue Klasse, we will make a major technological leap forward in electric drive systems,” said Oliver Zipse, CEO of BMW AG. “We want to significantly increase the energy density of the cells and at the same time reduce costs in material use and production. We will also significantly reduce the use of primary materials to ensure a truly ‘green’ battery.”

Read more here

Good Garage Scheme Top 5 feedback of the week

We have made the Good Garage Scheme Top 5 feedback of the week again, for the fourth time!

Once again, thank you to everyone that takes the time to leave us such great feedback online, to our faces or bring in treats to say thank you. We appreciate it so much, it really brightens our day.

We have been snowed under with extra work for a long time now and feel the pressure to return cars as quickly as we can. So much so we have forgotten to post we have now been open 6 years this March! The time has flown by!

Thank you to all our loyal, fantastic, friendly customers. We appreciate you all very much!

Who is diagnosing the problem?

Source HEVRA:

There’s something of a misconception by some drivers, that the diagnosis of modern cars is done by a computer rather than a skilled individual. In fact, the computer (an essential part of the diagnostic process) just allows the technician to see things as the car sees them, and it’s down to the technician’s judgement, skill and further testing to get to the root cause, which then leads to a successful repair.

Let’s take an example of a modern vehicle, such as the Jaguar I-Pace.

If the car has a problem, a fault may have been recorded in one or more of the vehicle’s 41 addressable electronic control units (there are more than this if you consider those that don’t have their own diagnostic address).

There will generally be a number of fault codes, some that point to the cause of the problem, and some that are a consequence of the problem.

Let’s say we narrow down the fault to the Battery Energy Control Module (BECM). This ECU is capable of picking up 208 different errors.

Let’s say we have fault code P0ABF, Hybrid/EV Battery Pack Current Sensor “A” Circuit.

This fault has three possible definitions, so lets say we narrow it down to P0ABF-64, Hybrid/EV Battery Pack Current Sensor “A” Circuit- signal plausibility failure.

It’s now the technician’s job to find the root cause of the problem, so it’s out with the wiring diagram. The current sensor is located within the Battery Electrical Module, which has approximately 25 wires, all of which are red.


The current sensor itself is a control module of sorts, and although it doesn’t have its own diagnostic address, it communicates with the BECM using a controller area network. The connectors are gold plated for reliability, and pass through a ferrite core to reduce interference, before going through a connector, coming out a different colour, and finding their way back to the BECM.

The technicians needs to determine whether the fault is in the power supply, ground connection, network connections or the sensor itself. Furthermore, the fault could be a consequence of another problem- for example a partial short or a high resistance could lead to more or less current passing through the sensor than expected, in which case the fault could be somewhere else entirely. Equally, the software programming might not have allowed for the current draw of a particular circumstance, in which case the sensor may be reporting correctly and a software update may be required.

If you think this all sounds rather complicated, it’s the way of the modern vehicle, regardless of brand or even fuel type- those with combustion engines have similar levels of electronics, coupled with mechanical, thermal and fluid dynamics to consider as well.

Of course, it’s all in a day’s work for the skilled technicians in our network of garages, but hopefully this gives you some insight into why fault finding and diagnostics take the time they sometimes do and why cars can’t be diagnosed over the phone.

To ensure the best possible service to drivers, our member garages need to have a suitable qualification which ensures they know the principles and fundamentals of electric and hybrid vehicles. Our newsletters keep them up to date with new developments and allow them to gain experience from unusual problems repaired by others. Our unique vehicle-specific information means they can be familiar with a particular make and model the first time they see one, and if necessary all of our members also have access to our unlimited technical support should they need a second opinion or some help.

Vehicle Servicing is Important

Here at Burch Motor Works our regular customers are very good and have their vehicles serviced regularly at the correct intervals, based on mileage or time.

However we do have a few vehicles recovered to us from time to time with large engine failures, timing chains, turbos, worn shell bearings, carbon/ sludge build up to name a few. The thing they usually have in common is the service indicator is miles overdue when we check it. There really is no excuse, the services intervals are normally 12-20,000 miles which is a long time between oil changes, with a big warning when you start the vehicle

Please remember, to look after your vehicle and engines health, please service at the correct intervals to save yourself on a potential large engine failure and keep your vehicle safe. Along with keeping a higher value if you decide to sell the vehicle is future!

We are still open

We are still open as normal being an essential service and MOT Station. Listed in the picture below from the latest Gov National Lockdown guide.

We are still carrying out our contactless service with payment by card over the phone the preferred method of payment to reduce contact and time in our reception. Masks are to be worn in reception.

If you’d prefer to carry out all interactions outside just let us know and we can carry that out.

If you have any further questions please get in touch. We are currently booking approx 5 weeks in advance, of course taking on extra breakdowns where possible.

Thank you for your patience

Christmas & New Year Opening Times

Thank you again to all our fantastic loyal customers for their business and support in this strange 2020 year!

  • Closed week of 21st of December for Christmas
  • Open 29th, 30th and 31st December.
  • Closed for New year.
  • Open Monday 4th January for 2021

Please note we are now booking towards the end of January. Of course we will help where we can with extra breakdowns.

To all our fantastic customers. Have a great Christmas & New Year!


We are still open – only a few spaces remaining in December!

Following a few enquires since the lockdown announcement on Saturday.

We are still open as normal being an essential service and MOT Station. We are still carrying out our contactless service with payment by card over the phone the preferred method of payment to reduce contact and time in our reception. Masks are to be worn in reception. If you’d prefer to carry out all interactions outside just let us know and we can carry that out.

If you have any further questions please get in touch. We only have a few spaces remaining in December before Christmas to book in. Contact us or use our online calendar to book your car in or ask any questions you may have

Fixing water damage

The owner of this BMW X1 we’re glad they had their vehicle recovered to the right place.

The vehicle had broken down, with the RAC unable to communicate to the engine ecu (DDE), they could not go any further.
Once on site, we investigated to find no communication to the engine ecu also. We accessed the engine control box on the rear left of the engine bay to find previous water ingress into the box. Once the power supply, earth and can communication wires were checked, present and correct. It was obvious the water ingress has damaged the engine ecu.

If this vehicle went to a dealership it would be a new unit only at £1500 for an ecu, plus their excessive labour costs. Fortunately here at Burch Motor Works we have specialist equipment to allow us to fit/ program used ecus to most BMWs & Minis, which is difficult to get around the immobiliser functions BMW have added to prevent this repair being carried out. Of course this gives a great saving. Which made this whole repair less than a quarter of the price of a new one… get in! A hole has now been added to the bottom of the ecu box to prevent the fault reoccurring.

The cause of this fault is blocked water drains from leaves around the windscreen scuttle. If your vehicle is regularly serviced with us all drains are cleaned during the service to prevent these issues from occurring

  • Right Diagnosis
  • Right Repair
  • Right Price
  • Right back on the Road

Learn more about our Fault Investigation service