Holts Sealit Leak Repair 250ml, (Packing May Vary)

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

Cooling system was leaking from a faulty cap when I used this so a lot of it was probably lost, but it still fixed the persistent leak (think it was from the P gasket but might have been anywhere round there). months later it's still good. Great stuff.

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).

all ok

Use this at your own risk. Brought this to seal small head gasket leak. Followed the instructions to the letter. This stuff clogged everything up. Distroyed my thermostat and heater matrix and almost Distroyed my water pump. It part clooged my radiator. Wish had never put this in my car

Tried this in my stag which was leaking around the inlet manifold. This was the fault of the garage that replaced the core lugs (badly). Perhaps it was a lot to ask, but at first it sealed the leak after a short period, but next time I used it is leaked again then again sealed. This repeated for two or three times till the leak got so bad it could not be sealed. In effect it was sealing the leak but couldn't understandably repair the gasket beside it. Car now has engine stripped down to replace gaskets.

I had a leak in my engine coolant system - after topping it up, I’d get a warning light after approximately a week, so probably only a small leak in my system.I followed the usage instructions and this product worked perfectly. It’s been many months now since using it, and my engine coolant levels are still normal.

I was topping my coolant on a weekly basis, 1 litre. I was skeptical but thought if it works then I save myself hundreds of pounds. Followed the instructions and haven’t had to top up the coolant since then, over a month ago.It’s fairly straightforward, make sure the heating is on full blast and let the engine run for 30 minutes then let it cool down for few hours! My engine was warm when I poured the liquid, and make sure to SHAKE the bottle well :-)