--- title: Trythogga: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/trythogga-cornwall/ location: Trythogga county: Cornwall latitude: 50.129730 longitude: -5.530220 service: AdBlue in a Diesel Tank updated: 2026-10-26 --- # Trythogga: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? AdBlue already in your diesel tank? In that case put this page down a moment, leave the ignition and motor off, and call 0333 366 0103. Caught before your motor runs, it's generally a drain and a thorough flush, done where your car is around Trythogga. Reading in advance? In that case the rest explains how it happens and how to stop it happening at all. ## AdBlue in a diesel vehicle, and its separate tank Plenty of current diesels on the roads around Trythogga and Treneere carry two liquids, not one. Diesel goes to the motor. Kept in a tank of its own, AdBlue is sprayed into your exhaust stream and cleans it. Each tank comes with a filler of its own. On a lot of motors the two sit side by side under the same flap; on others the AdBlue filler is in your boot or under the bonnet. The diesel side is filled at the petrol pump all the time. The AdBlue side is fuelled far less frequently, usually from a bottle, and usually by a person who has to stop and think where it goes. It is in the gap that the error lives. ## Trythogga: how AdBlue in your diesel tank occurs It's hardly ever carelessness. Three things tend to line up. The warning comes first. As AdBlue runs low the car tells you, and if it runs out completely, your vehicle drops into limp mode. So the top-up is done in a hurry: on a driveway off Trythogga Hill before work, or in the car park outside The Coldstreamer on the way home. The old car's filler is where your hand goes — yet a hire car, a new motor or a company car keeps the fillers elsewhere. That is a second thing: an unfamiliar vehicle. Lastly, the spout goes in: a diesel filler or AdBlue filler, it goes in as easily, and after the tip begins, nothing halts it. Whether it happens in Trevarrack or the middle of Trythogga, it is the same few seconds. ## The AdBlue filler and the diesel filler: telling them apart Be it a Trythogga forecourt or a driveway out in Penzance, spend a few seconds on these before any goes in. - Blue and lettering: an AdBlue cap is regularly blue, or says "AdBlue", where a diesel cap normally does not. Go by the cap, not where it sits. - On many cars, size tells: AdBlue gets the smaller filler neck. - Check inside the fuel flap: many motors carry a label there showing which fuel goes where. - In your boot or under the bonnet: that's where the filler is if it is not by your diesel cap, and the handbook tells you which. - The previous driver knows. Ask when you pick up a rental or fleet car — at Penzance's car park, say — not once the light appears. ## Keeping AdBlue out of the diesel tank when you top up A routine for the day the light comes on, wherever in Cornwall that is. - Park and switch off. Not on a slope, not with your motor running, and not in a rush on the side of B3311. - Say "AdBlue" out loud as you unscrew the cap, after finding the AdBlue filler and reading it. Daft, perhaps, but it does the trick. - If both sit under one flap, check the diesel cap is still closed before you lift the bottle — then leave the car on. - Finish when that tank fills or the bottle is empty; before that, tip gently through its built-in spout. - Before starting the car, shut the cap and look again that your diesel cap was never opened off. Find during the second or third stage that AdBlue went in the diesel filler? That is where you stop. Never carry on to stage five. ## Put AdBlue in the diesel tank in Trythogga already? Then the order of things is short. Don't start the engine. On plenty of diesels your ignition alone runs the fuel pump, and so do not switch the car on. AdBlue does not mix with diesel — it sinks to the bottom of that tank, where the fuel is pulled from — so don't top up with diesel to dilute it. The staff at Tesco, Sainsbury's or any forecourt will normally help pushing your car away when you ask. On your own drive in Trythogga? So the car stays where it is. When the motor has run by now, pull over safely and switch the vehicle off. On the M5, over 50 miles from Trythogga, that means the next exit. Tell us roughly how far it went: a run towards Truro, under 25 miles away, is a bigger job than a short hop across Trythogga. ## Our arrival around Trythogga, and what takes place next Our engineers come to the car wherever it has stopped, whether that is outside Gulval School, close to Gulval Village Hall or on your own driveway. Those replies determine this work and our quote, and so we ask what went in, roughly how much, and if it's run. Nobody heads out until you've heard the price by phone. Draining that tank comes next, then a thorough flush of the system. Not like petrol, AdBlue forms crystals and attacks some fuel-system metals, and neither clears out unaided. That is why it matters more. A test comes last: before that, clean diesel is added, and the filter is flushed or replaced as needed. We do not leave until it has been fired up and is running correctly. Most jobs are done in about half an hour after we arrive, as long as the engine hasn't run — and the pumps our technicians use are fine on a busy forecourt and quiet at night outside a house. No money upfront; you settle up on the day. At the end, a VAT invoice and the report from the engineer are handed to you for your insurer. It's worth looking at your insurance while we travel to you: misfuelling cover comes with many policies. ## About Trythogga itself Trythogga is a small suburban area in Cornwall, situated near the coast at an elevation of around 20 metres. Trythogga lies within a short distance of several nearby places, including Trevarrack, Chyandour, and Gulval, and is approximately 23 miles from the city of Truro. Trythogga is characterised by its predominantly semi-detached housing stock, reflecting the typical residential development patterns of the region. ## AdBlue drains around Trythogga, and Cornwall beyond Throughout TR postcodes, the vans that cover Trythogga — a residential suburb — work the surrounding places too, Gulval and Chyandour included. Our van gets to you fastest with a postcode starting TR18 3. Your car remains put. A drive, a lay-by on the way to Princess May recreation ground, a side street near St Gulval: our engineers drain it where it stands. Ring and ask instead of guessing if you are near a boundary, or somewhere hard to explain, like the back of St John the Baptist. ## Trythogga people: the short version Pour no AdBlue until you have read the cap. Even so AdBlue in the diesel tank? Petrol in Diesel can empty it where it stands, anywhere around Cornwall: keep the vehicle off and phone 0333 366 0103.