Sealit Leak Repair 250ml, (Packing May Vary)

*UPDATE* This has gone for thousands of miles and still no need to top up water or oil. Completely fixed. Very happy. The car is 19 years old - getting the head for less than a tenner before it was almost a grand has been amazing. Cannot recommend this more. Was going to buy another today (another car) but there's a minimum order of five right now, and I don't need that many... Unfortunate but I'll go to my local motor factors instead. I tried Wynne's coolant system seal and it didn't do the job - it's supposed to be as good as RadWeld Plus. I didn't want to bother with RadWeld Plus as my coolant went down disturbingly quickly. I've had a head gasket problems in Astras before, and I was worried it was that. No obvious leaks anywhere, and only going down when it's running. This has been in for a good few hundred miles and a couple of weeks and it's not gone down one bit! Literally drop it in and run the engine, no special timing or anything... Very impressed, and a great price.

Cylinder to coolant leak,was not too bad, this stuff stopped it.

Did the job it claimed which saved me £250 less product cost ,as with many modern cars engines seem to be designed for lack of access for the layman

Context - Steam/White vapour from the exhaust and losing coolant, overheating after about 45min - 1 hour. Looked like a head gasket problem. After trying Wynn's radiator stop leak I thought I'd give this a go, it's supposed to be stronger stuff. It worked. How I did it was let the engine warm up a bit first (but not too hot) with heating on and valves open, then poured into the header tank (1.6 petrol 2007). Then after 5 mins, there were still a few drips of coolant, so took it out for around 15mins on back roads, giving it up to 5-6000 revs before changing up and making sure there was plenty heat coming in (heater still on). Got back and with the engine still running and heater still on checked again and seemed to be no more drips. Topped up the coolant when the engine was cold and the GF started it with heating on and no white smoke/vapour from the exhaust and no drips. Long story short - It worked but had to put plenty of heat into the engine and still early days yet so yet to see how permanent it is (unable to tell how long it will last is the only reason for missing fifth star).

Head gasket on the way out in my old school VW t25 so used this and worked perfectly fine for me. The exhaust gas stopped leaking into the coolant which was exploding everywhere when warm. Worked well enough for a 300 mile drive for the new engine to be installed so very pleased

Delivery to Germany was faster than expected. Holts Sealit did not work in my car. Opel Astra F Engine: X16SZ. Pressure and bubbles in cooling system. No improvement to detect after usage of Holts Sealit. Caused by this, it is sad situation for me.

I think if you use this correctly, it will work,, it's best to remove the thermostat, install this, drive around, and see if you are losing water. If not, reinsert the thermostat. I have been using the car for a week now with no problems.

I have a Saab 3.0tid with a slight coolant leak, sadly just blocked my radiator and made it worse