Crystal Clean & Protect - Prevents AdBlue® Crystallisation - 125ml

Works like magic. I had one of those dreaded warnings come up to service urea system and given 700 miles until the car would not start. I poured 1 bottle of this into the Adblue tank and drove 10 miles and it cleared the crystalized injector and warning was gone. Avoided a hefty repair.

I have a Mercedes GLE with a 32 litre Adblue tank. I added this to an approximately 2/3rds full tank, so slightly under dosed (product is meant to be for 15L). Car has 70,000 miles on the clock, so wanted to start cleaning the components, to try and prevent costly repairs (which anyone with a Mercedes will know can be extremely high). I can’t say it made any difference to the drive, or noticed any exhaust difference, but I was using this as preventative rather than cure. The price is very reasonable for peace of mind. Adblue additives are becoming much more common now (if you read motoring forums). Despite an earlier review saying it destroyed their Mercedes SCR system, it seems to be ok in mine. I regularly used Wynns diesel additives, so trust this brand a lot. Their products are very good overall, and they have been around for a long time, with mainly 5 star reviews. Seems like a good product, and hopefully it will clean the Adblue/SCR system, and prevent problems. I will be using with every Adblue top up going forward.

I had an engine fault code regarding my Adblue system. Car said I had about 600 miles before car won’t turn on. Very scary. Garages told me it could be very expensive repair. So I used this stuff hoping that my problems would get resolved. And to my surprise it did. Emptied it in my Adblue tank.. drove for around 70 miles and job was a good one. Turned out to be a blocked def injector which this stuff cleaned up. And now no more fault codes as it went away on its own. I will keep using this Crystal Clean & Protect on every Adblue refill.

I have been plagued with AdBlu messages for the past 9 months. Every day I was getting a variety of different messages, despite having a full tank. It would count down to 500 miles to go and then go to 700 miles, then 1500 miles etc etc. And sometimes I would get the Urea message too and/or Engine Failure and/or Emissions Fault etc etc. I stumbled on to this, and decided to give it a try. After 10 days I still had messages, so I booked it in to a garage, but they had a two week waiting list. While waiting the two weeks, all the messages have now completely gone. So I have now cancelled my garage visit and I am keeping my fingers crossed! I think it took about 3 weeks and 400 miles of driving. The garage advised me that it is possible to buy Adblu that contains an anti crystallisation additive, although I will probably continue to use this stuff. If the messages come back, then I will update this review (and book the car back into a garage!)

Unstuck the level. The AdBlue level didn’t increase till I added this, then only gradually. Not sure it was this that cured it, but seems to be showing AdBlue level correctly now!

I'm not an expert by any stretch of the imagination and so I can only state the following: My 2021 Vauxhall Combo, when bought, (13th December 2025) had 41000 on the clock. Adblu was showing 1700 until no start. At the end of March 2026 an on board message reported 1500 until no start. 1500 is the usual number when messages start showing. I added 10 ltrs of adblu. 2 weeks later, the adblu message was still coming up at engine start. Doing some research, I chose Wynn's additive and one week later the 1500 dropped to 1300 and then went back up to 1700. I can only assume that Wynn's, like any additive, took time to remove possible crystallisation around jets and sensors. One bottle, (125ml) treats 15 ltrs, the Vauxhall Combo holds 17 ltrs so I can only wait now until the next 1500 warning, add the 10 ltr adblu plus Wynn's Crystal Clean and Protect and see how long it takes to register. Just so you know, I also use Reddex in my Diesel.

I use this every time 2.top up add blue message comes up. This is just prevention of issues that could cost hundreds of pounds to fix. I like my money in my pocket not the garages.

It worked last year in hot weather this year not working at all. What to try next?

L’ho acquistato perché la macchina, quando entravo in funzione il sistema di AD blue alcune volte mi dava degli allarmi sul quadro strumenti dovuto a un basso livello di temperatura raggiunta, perché appunto la quantità di AD blue che veniva iniettato era insufficiente, quindi ho supposto che si fossero creati nei cristalli nell’impianto in quanto io ho la macchina di Bu da poco e non sapevo la necessità di aggiungere degli additivi in modo che il liquidò non cristallizzasse, quindi l’ho usato con molta paura anche perché avevo paura che i cristalli potessero comunque intasare completamente il iniettore una volta che questo additivo entrava in circolazione e faceva smuovere i cristalli, appunto però nel mio caso tutto è andato alla perfezione, quindi penso che questo additivo abbia sciolto completamente tutti i cristalli e che l’impianto si sia liberato senza comunque avere poi più allarmi quindi molto contento di questo prodotto ovviamente è un po’ più caro però nel mio caso ha risolto i problemi, quindi continuerò ad usarlo

Mein Citroen Berlingo zeigte mal wieder die Adblue-Lampe und ich habe beim nächsten Tanken auch Adblue-Flüssigkeit vollgetankt. Danach ging allerdings die Adbluelampe nicht aus, es kam die Meldung 'in 1000 km kann der Motor nicht mehr gestartet werden'. Das zählte alle 50 km weiter runter und es kam zusätzlich die Motor-Lampe. Mein freundlicher Werkstattmeister sagte, dass bei diesem Typ sehr oft in diesem Fall der Adbluetank getauscht werden muss, der kostet so etwa 1000 €, weil da die Punpe und die Elektronik mit dem Tank eine Einheit ist, plus seine Arbeitskosten. Er stellte mir die Fehleranzeige wieder zurück, um mir Zeit zum Nachdenken zu geben. Am nächsten Tag ging allerdings der Countdown auf dem Display wieder los. Einem Tip aus einem Forum folgend habe ich mir angeschaut, welche Lösungen es für solche Fälle gibt ... und landete bei Adblue-Zusatzflüssigkeiten, die das Auskristallisieren von Adblue verhindern sollen und sogar die Kristalle wieder lösen sollten. Mir fielen da zwei Mittel auf, deren Hersteller mir seit Jahrzehnten bekannt waren: Wynn's und Liqui Moly. Beide gibt es bei Amazon und ich bestellte beide. Der Unterschied: Wynn's kommt in einer kleinen 125ccm-Flasche mit langem Hals, praktisch fürs Einfüllen, und empfiehlt den ganzen Inhalt auf einmal in den Adblue-Tank zu kippen. Die Anderen empfehlen jeweils bei jedem Tanken nur 25 ccm. Meine Strategie war ganz logisch: ich wollte zunächst Wynn's Tinktur ausprobieren und wenn das nicht hilft, in der praktischen Wynn's-Flasche die andere Tinktur nachkippen. Zu Letzterem kam es dann allerdings nicht mehr: Wynn's Cristal Clean & Protect reingekippt, zur Autobahn gefahren und dann nach etwa 5-7 km ging die Adblue-Lampe aus! Am nächsten Tag bei einer längeren Dienstfahrt ging dann nach 20 km auch die Motor-Lampe aus. Und blieb aus! Die kleine Wynn's-Flasche kostete mich übrigens weniger als ein Fünftel von dem Rechnungsbetrag, den mein Werkstattmeister fürs Zurückstellen der Fehleranzeige verlangt hat...

Snabb leverans

waste of time

Compra muy recomendable para vehículos diésel con sistema AdBlue, especialmente si quieres prevenir problemas y cuidar el sistema SCR a largo plazo. Compramos este aditivo de Wynn’s para utilizarlo como mantenimiento preventivo y la verdad es que transmite bastante tranquilidad en vehículos modernos diésel. Lo primero que destaca es que está pensado para ayudar a prevenir la cristalización del AdBlue, uno de los problemas más habituales en sistemas SCR con el paso del tiempo. En nuestro caso empezamos a usarlo de forma preventiva después de leer bastante sobre averías relacionadas con cristalizaciones y obstrucciones. El uso resulta bastante sencillo y el formato de 125 ml es cómodo para añadir directamente al depósito siguiendo las indicaciones. Otro punto positivo es que ayuda a mantener el sistema más limpio y favorece un funcionamiento más estable del tratamiento de emisiones. Además, al tratarse de un componente importante y caro en muchos coches diésel modernos, cualquier mantenimiento preventivo se agradece muchísimo. También nos gustó bastante que no requiere herramientas ni procesos complicados. El producto transmite buena sensación de calidad y la marca es bastante conocida en aditivos para automoción. En cuanto a resultados, obviamente no es algo que se note de forma inmediata como otros productos, pero sí aporta tranquilidad para el mantenimiento del sistema. Otro detalle importante es que puede resultar especialmente útil en coches que hacen muchos trayectos cortos o urbanos. Pros: * Ayuda a prevenir cristalizaciones del AdBlue * Fácil de utilizar * Formato práctico * Ideal como mantenimiento preventivo * Puede ayudar a evitar averías costosas * Marca conocida en automoción * Compatible con vehículos diésel SCR Contras: * Los resultados no son inmediatos ni visibles * No sustituye un buen mantenimiento del vehículo * Conviene seguir bien las dosis recomendadas Conclusión: Un aditivo interesante para quienes quieran cuidar el sistema AdBlue y prevenir problemas a largo plazo. Fácil de usar y recomendable como mantenimiento preventivo en vehículos diésel modernos.