Emission testing’s an area where good MOT emissions testing compliance really shows the difference between a workshop doing things properly and one cutting corners. Most of the problems we see don’t come from a lack of knowledge (although it sits in Section 8, Nuisance, of the MOT inspection manual if you want to refresh your memory). They come from small habits that creep in when a tester’s under pressure, in a rush, or simply hasn’t had the reminder they needed.
Here’s what we look for, and what it tells us about the state of MOT emissions testing compliance at a station.
Finding the Plate Value: The First Test of MOT Emissions Testing Compliance
Every diesel emissions test should be carried out against the vehicle’s plated value. On more modern cars, the emission plate value can generally be found on the chassis plate, but for plenty of vehicles it’s tucked away somewhere far less obvious, a small sticker in the engine bay, on the door column, or buried in the boot! It takes a bit of persistence to track down, and that persistence is exactly what good MOT emissions testing compliance depends on.
Older cars bring a different challenge. The plate value may have been scratched off, worn away, or removed. It’s worth remembering that the default value used when no plate value is available is always considerably higher than the original, which gives the vehicle a much better chance of passing. That’s precisely why it matters so much that testers make a genuine effort to find the real figure rather than reaching for the easier option.
When “No Plate Value Visible” Becomes a Pattern
Selecting “no plate value visible” is sometimes the honest and unavoidable outcome of a proper search. The trouble starts when it becomes a habit rather than an exception. A tester who logs this option repeatedly, particularly on newer vehicles where the plate should be straightforward to find, is going to raise questions, and rightly so. Solid MOT emissions testing compliance means the search happens every time, not just when it’s convenient.
The same pattern shows up with “no oil temp measured”. Skipping the OBD reading might save a handful of seconds, but it’s a shortcut that’s easy to spot when it happens too often for one tester. Both of these are exactly the kind of small, repeated habits that chip away at a station’s overall compliance record, even when no single test looks obviously wrong.
The Health and Safety Side Nobody Should Skip
There’s a simple safety rule that’s routinely ignored, and it’s worth repeating clearly: a tester carrying out the engine revving element of a diesel emissions test should be sitting properly in the car, not leaning in with one foot on the accelerator. It’s an easy habit to fall into, but handbrakes that aren’t fully applied or vehicles left in gear have, on rare occasions, resulted in the car moving off on its own.
So…remember – bottoms in cars, always!
It’s a small discipline that protects both the tester and everyone else in the workshop, and it’s as much a part of MOT emissions testing compliance as finding the right plate value.
Connected Equipment: Keep an Eye on Your Test Logs
More MOT stations now run equipment connected directly to the DVSA’s MOT testing service. It’s a good system, but it does rely on staying connected, and we’ve recently spotted a few stations where previously connected equipment had quietly dropped offline. Sometimes it’s a software update, sometimes a change to the workshop’s wifi, and sometimes equipment was switched to manual for a specific job and never switched back.
Whatever the cause, Section B of the MOT testing guide is clear that where connected equipment can’t reach the MOT testing service but is otherwise working correctly, testing may continue for up to 7 calendar days from the point the fault began. After that, testing can’t continue for any vehicle that requires that equipment. If a station needs longer, DVSA may, at its discretion, consider a request to continue testing beyond the 7 days, but the Authorised Examiner must email motadministration@dvsa.gov.uk before the initial 7-day window runs out, explaining the reason for the request.
The most reliable way to catch a connectivity problem early is to keep a regular eye on your test logs. Connected equipment shows up there, so a quick weekly check is often all it takes to spot a dropped connection before it becomes a bigger problem for your MOT emissions testing compliance.
Building These Habits Into Everyday Practice
None of this calls for new equipment or a lengthy training course. It’s about the small, consistent habits that add up to genuinely good MOT emissions testing compliance: taking the time to find the real plate value, using the OBD equipment properly every time, sitting in the car for the rev test, and checking the test logs regularly to make sure connected equipment is still talking to the DVSA. Stations that build these habits into their everyday routine rarely have anything to worry about when an assessor comes to call.
If you’d like support reviewing how your team handles diesel emissions testing or connected equipment, that’s exactly the kind of thing we help with. Get in touch and we’ll help you build MOT emissions testing compliance that holds up, every single time.