Ask Honest John

Most recently answered dpf issues questions
I bought a 2006 Hyundai Tucson in October 2017. The engine warning light was flashing when I test drove it and I was told that this was the DPF. I was aassured it would be fixed and it was okay when I...
What should I look out for when buying a 2006 Volkswagen T5 Caravelle?
I’ve recently bought a used car on finance with a deposit of £1000. On day three of having the car (less than 50 miles later), the engine management light came on. I rang the dealership and took it in....
I have a 2008 BMW 3 Series Touring 3.0d. I do 20,000 miles per year on A roads, at high speeds, and change the oil and filter very regularly. A diesel particle filter warning light has now come on. Why...
The oil appears to be reading high in my diesel E90 BMW 3 Series, both via the dashboard indicator and also by manually checking (after driving approximately seven miles and leaving five minutes to cool)....
The DPF warning light has come on in my Audi Q3. It had the emissions update in March 2017. Audi have said that they will charge me £60 for diagnostics. If the problem is caused by the update then they...
I have a Peugeot 2008 1.6-litre BlueHDI. I'm aware that travelling very short journeys is not good for diesel cars. However, occasionally it is unavoidable to undertake such journeys. Is it beneficial...
I've been reading some of the problems Mazda 6 owners have with DPFs. My Mazda 6 now has 93,000 miles on the clock, it had 90,000 when I bought it. I mostly do short runs (less than 15 miles). What should...
Can you please advise how to regenerate the DPF on a Mercedes-Benz E-Class?
I have a 2008 Renault Koleos 2.0d. In the past two weeks I've done four journeys in excess of 50 miles at high speed (dual carriageway). A couple of days ago, a warning appeared saying "check exhaust emission"...