Put Coolant in the AdBlue Tank?
Coolant, antifreeze and AdBlue all live under the bonnet or behind the fuel flap in similar-looking containers. If coolant has gone into the AdBlue tank, don't start the engine - we drain, flush and refill it at the roadside, 24/7, across London, Essex and Sussex.
Call for AdBlue Tank Drain: 07393 440 255Why coolant in the AdBlue tank is a problem
The AdBlue tank feeds a pump, a quality sensor and a dosing injector in the exhaust. Anything other than AdBlue in it puts every one of those parts at risk - but as long as the engine stays off, the problem stays in the tank.
Engine coolant is a glycol (usually ethylene glycol) mixed with water and corrosion inhibitors. Unlike diesel it mixes freely with AdBlue, so the whole tank is contaminated immediately and the quality sensor reads out of specification straight away.
Glycol is sticky and does not evaporate. Once it has been pumped through the AdBlue system it leaves a gummy residue in the pump, lines and dosing injector, and the additives in coolant can react with the urea and damage the SCR catalyst coating. Draining before the engine runs keeps all of that in the tank, where it is easy to remove.
Warning signs of coolant in the AdBlue tank
- Immediate AdBlue quality warning when the ignition is switched on
- Countdown to 'no restart' or engine limp mode
- Fluid at the filler neck is pink, orange, green or blue and slightly slimy to the touch
- Sweet smell at the filler (typical of glycol)
Immediate action required:
Do not start the engine. If it is running, switch it off as soon as it is safe to do so.
Do not top the tank up with AdBlue to 'dilute' it - the whole tank has to be drained.
Call 07393 440 255. Tell us the vehicle and roughly how much went in, and we will give you a fixed price.
How we fix coolant in an AdBlue tank
- Complete drain of the contaminated AdBlue tank through the filler
- Tank and pick-up flushed with fresh AdBlue until it runs clean
- Pump filter and quality sensor checked
- Refill with fresh ISO 22241 AdBlue
- Fault codes cleared and the system checked with diagnostics
- Contaminated fluid disposed of as hazardous waste
Already started or driven the vehicle?
If the engine has been run, switch it off as soon as it is safe. We drain the contaminated AdBlue, flush the tank and pick-up with fresh fluid until it runs clean, refill with new ISO 22241 AdBlue, and run diagnostics to clear the fault and check the pump and injector. If glycol has reached the dosing injector we will explain the options before any further work.
Other AdBlue mix-ups we fix
Coolant in AdBlue Tank FAQs
Common questions about coolant in an AdBlue tank.
Is coolant in the AdBlue tank as serious as diesel?
Yes, in a different way. Coolant mixes with the AdBlue immediately, so the whole tank is contaminated, and the glycol leaves a sticky residue wherever it is pumped. Caught before the engine runs it is a straightforward drain and flush; after the engine has run, the pump and dosing injector need checking.
What if I have already driven the car with coolant in the AdBlue tank?
Stop as soon as it is safe and do not restart. Call us: we drain the tank, flush the tank and pick-up until the fluid runs clean, refill with fresh AdBlue and run diagnostics to clear the fault and test the pump. If glycol has reached the dosing injector we will explain the options before any further work.
Will the AdBlue pump need replacing?
Usually not if the tank is drained before the engine runs. We test the pump and quality sensor after the flush; a replacement is only needed if the contamination has already been pumped through the system and caused damage.
Do you drain AdBlue tanks on vans and trucks as well as cars?
Yes. AdBlue is fitted to most modern diesel vans and all HGVs, and the fillers are often side by side with the diesel filler. We attend cars, vans, light commercials and trucks across London, the M25, Essex and Sussex, 24 hours a day.