Holts Speedflush Coolant Flush, Universal Car Radiator Flush, High Performance Coolant Flush For Radiators & Cooling System, Quick & Easy To Use, Prevents Overheating, Suitable For All Cars, 250ml

Used to flush the coolant system in a 2014 Audi A3 2.0 TDI. This stuff worked great, as I had a suspected blockage within the heater core. Super effective at removing all the hidden gunk and debris within the system. Before I used this, I had good colour in the coolant. I bought two bottles of this. The first bottle went in with the current fresh coolant, and it pulled out so much gunk which was probably the culprit of the blockages. I drained the system and put in fresh distilled water, along with another bottle of this stuff, and that also again pulled out so much gunk. Finally drained that and put in fresh coolant.The difference between before and after on the heater core is massive. I am usually dubious about additives for cars, but this did as advertised, and very easy to use, as just a pour in application. Good value for money. I would consider buying this every few years to run and use before doing your own coolant replacement as part of preventative maintenance, as the price of this far out weighs any price for a mechanic to tell you the cost of them doing a flush.I used this product over the course of a day, running the car for around an hour each time at full temperature, to have it really work as well. Probably works well as recommended by the manufacturer as well. Will definitely being buying this again and using it again in the future.

Does the job would recommend when you do your coolant flush intervals. For optimum results use with distilled water in the expansion tank only.

I didn't have any real blockages but used some of this in a 20-year-old car before I changed the radiator.Lots of crusty bits came out with the coolant - but I had to change it again as another job meant draining coolant (and reusing is just jank!) and more definitely came out again. As it happens, the NEXT time I did this it was basically clean; so I wouldn't worry - maybe do a second flush with only coolant/de-ionised water if you are using this.I can't say for certain but the same car has had heating issues since - only half the vents will blow heat. Probably unrelated as I did flush the heater matrix and nothing came out.

Good quality product

Flushed away rust and sludge easily. Great price and dispenses easily

Had mayo in my coolant due to head gasket failure. I followed the instructions and it definitely shifted more muck than a water flush alone, but I think it would be better if run in the engine for longer and at higher temperature to shift any oil stuck. But cheap price so I'll probably buy more and give it another flush when I do the oil next.

Good worked wet great value

Not much I can say, done the job and was easy to do , good quality and was effective