AdBlue tank failure

I was reading through all the posts about the Adblue tank failure in a C4 Cactus group as the same thing has happened on my 15 plate C3 Blue HDi 100. Purchased in Oct 2018 with 10,032 miles on the clock for £7,500, I've covered 27,500 miles in the nearly 4 years I've owned it. A couple weeks ago, I got all the lights on the dash (fixed urea, service and engine), so took it to my local garage who've been looking after it since 2020. They said they were aware of this issue and a replacement cap sorted it in about 70% of cases, provided the pump wasn't already damaged, so that was replaced and faults cleared. £25 No effect, the lights all came back on again within hours, but this time with the countdown to 'starting prevented' at 700 miles and urea flashing. Next was the injector, which apparently was leaking and had corroded/split the exhaust, so that was replaced, the exhaust welded and codes cleared again which reset the miles till starting prevented back to 700. £290 No effect. I contacted Citroen who said I must take it to one of two authorised dealers to be diagnosed at a cost of £100. Needless to say, it needs a whole new tank at a cost of £1,617.98. Citroen have offered 42% of the price of the part only (which costs £1,275.60), as a goodwill gesture(!) so it would still cost £1080 to replace including labour, which I don't have. The miles remaining are now down to 150 before starting prevented and the car becomes a useless piece of metal on my drive.

Somebody in the C4 Cactus group said this back in 2020:
"VEHICLES ALL MODELS
EXPLANATION
On the affected vehicles check and if necessary replace the filler cap of the Selective Catalytic Reduction (SCR) system reservoir.
This campaign is in order to improve the venting of the reservoir, so as to avoid the lighting of a warning lamp on the dashboard and not being able to start the engine. In some cases the reservoir will have to be replaced."

During each of the 4 calls I've had with Citroen, I've told them I'm aware that they knew this was a problem and chose not to issue a recall and during none of those calls have they ever denied it. Also, when the cap was replaced a few weeks ago, the mechanic compared the two caps and could see the cap he took off was the original, non-venting one.

I wondered if anyone can confirm the legitimacy of above statement which was presumably issued to dealers by Citroen?

Hi

I can't confirm the statement, but it seems plausible to me. The vent will allow air into the tank that takes place of the ADblue. Without the vent, eventually the injection won't happen and a fault is called.


Unfortunately, I do not see how your fault (damaged tank, leaking injector and cracked exhaust) is going to be proved that these are due to the non-vented cap originally fitted.
Have you ever had to remove the cap before now to top-up the adblue? This would be enough to equalise the pressure, in the same way a vented cap would.


If the fault is cleared and the adblue is sensed as being injected then the countdown will reset.
Something is still blocking the injection and ultimately the miles until starting prevention is still counting down.

The clock is ticking on the countdown and if you can't find an alternative source and fitter of the parts, it may be better to take the Citroen offer and fight the cost later.

As you mention, the going to be worth parts only soon, so a runner will always be worth more than a non-runner.

Thanks for your reply.

I have found another forum where an email was sent out to a customer by their Citroen Dealer which read:
"Dear Sir/Madam,
Our manufacturer has asked us to notify you of a vehicle safety recall.
GCH WORKSHOP INTERVENTION
VEHICLES ALL MODELS
EXPLANATION
On the affected vehicles check and if necessary replace the filler cap of the Selective Catalytic Reduction (SCR) system reservoir.
This campaign is in order to improve the venting of the reservoir, so as to avoid the lighting of a warning lamp on the dashboard and not being able to start the engine.
In some cases the reservoir will have to be replaced.
Please empty your boot for the Recall purposes
This operation, considered essential, will of course be carried out free of charge and will require your vehicle to be booked in with us as part of our duty of care."

The cap has been off twice in 4 years; I'm not doing the miles for it to need refilling. For instance, in the first 18 months, I was doing average mileage, but during/after lockdown, barely anything; 3,376 in 2021 and 4,737 from its last MOT to now, so not enough to need to take the cap off.

The way I see it, in the above customer email, Citroen have admitted there is a problem (in writing) and a resolution that should have been done on my car before I bought it. Citroen should take ownership of the problem and fix it for free for everyone.