About Speed Tweaks
Diagnostics without
the corporate bollocks.
Real workshop experience, real diagnostic cases and straightforward explanations from someone who actually works on the things.
Demystifying diagnostics
Hi, I'm Ray.
I run a busy specialist workshop and I've spent years diagnosing, repairing and generally arguing with vehicles that don't want to tell you what's actually wrong with them.
Speed Tweaks is where I share the methods, tests and reasoning I use when diagnosing real faults.
I'm not here to pretend there's a magic scanner that tells you which part to replace. The aim is to help you understand what the vehicle is telling you, gather useful evidence and work through the problem logically.
0% corporate jargon
No magic scanners.
No parts cannon.
A fault code is evidence, not a diagnosis. Good diagnostics is about asking the right questions, understanding how the system works and testing the right thing in the right order.
Try guided diagnosis →The mission
Why I started
Speed Tweaks
If fixing modern vehicles really was as simple as plugging in a scanner and letting the screen tell you what to swap, life in the workshop would be considerably easier.
Unfortunately, cars didn't get the memo.
A code might tell you that something is outside the range the ECU expects. It doesn't necessarily tell you why. A sensor can report perfectly believable information while the thing it's monitoring is doing something completely different. And some systems simply don't have sensors telling you everything you'd like to know.
That's the bit of diagnostics I find interesting — working out what the evidence actually proves, what it doesn't prove, and what sensible test should come next.
Speed Tweaks exists to share some of that thinking with technicians, DIYers and anyone else who wants to understand their vehicle rather than just throw parts at it.
Meet Ray
Nearly 40 years of
pulling things apart.
I started working on vehicles when I was five on my grandparents' farm. That's where I learned to be a problem solver, not just a spanner swinger.
I was brought up by my mum, who worked bloody hard to give me every opportunity she could. A lot of my attitude to work probably came from her — get on with it, figure things out and don't expect anything to be handed to you.
She always encouraged whatever mechanical thing I was interested in next, although I'm fairly sure she'd have preferred it if I'd joined the Air Force rather than spend the next 40 years fighting with broken cars. 😂
Fast forward nearly 40 years and I'm still fixing things, still diagnosing strange faults and still learning — and, depending on the day, I still hate the motor trade.
That last bit is only partly a joke.
The important bit
I don't know everything.
Nobody does. Modern vehicles are too complicated for that. Diagnostics is as much about knowing what you haven't proved yet as knowing what you have.
So the information here will keep growing as I work on more vehicles, make more videos and inevitably discover more inventive ways manufacturers have found to make our lives difficult.
Who is Speed Tweaks for?
Anyone who wants to understand the fault before buying the part.
You might be a technician, an enthusiastic DIYer or simply an owner trying to make sense of what your vehicle is doing. The level of knowledge will vary, but the basic principle stays the same: start with what you know and gather evidence from there.
Still here?
Come and watch me fight with some cars.
The Speed Tweaks YouTube channel has real diagnostic cases, repairs and the occasional vehicle that refuses to behave itself.
Visit Speed Tweaks on YouTube →