K-Seal Ultimate

The product works great, had to unfortunately use it on my stage 3 3l a5 diesel. Temporary fix, While while I rebuild the engine, but it worked immediately, I have tried others, steel seal etc. None worked except this, however, I do believe it did damage the thermostat, but I can't say it definitely was this. Recommend.

Did not work for me sadly only a very small amount of steam from head gasket but still failed to seal

Well what ever I done with this it resolved the issue and has saved me over£800 for repair, works well, had no bother since applying it

stops leeks

A leak on the coolant inlet manifold on my jag stype,, part cost £40 but quoted £1000 plus for labour, thought I would give this a go after watching a sales ad , said it would also work on plastics, I really didn't have much hope , but bloody hell it worked, I was having to top up after a run of only a few miles, very noticeable leak , now nothing, not a drop ,couple of hundred miles now and still all good, fingers crossed, excellent product, worked for me , would recommend

Not sure how many stars to give this?? I have a BMW X5 4.8is V8 Petrol. I am losing water - but only a tiny bit poss 0.25L each week. Slight steam from exhaust when idling but again not much & hard to tell if coolant. No water in oil & no oil in water... I can only imagine it must be a tiny head gasket problem. Mechanic says no leaks. Car still drives like a dream. I have dosed the engine with one of these and given other positive reviews you would think that it would have done the trick? Maybe with the engine size I need 2 lots - however do not want to waste another £24 if it does not do the trick - really stuck - any wisdom on here? also noticed product says money back if it does not work - I wonder how to invoke that if I buy another and no joy? M

My trusty 1996 Diesel car of 17 years had to be sold due to the stupid and criminal extension of ULEZ (extended outside of the A406, by the London Mayor). Unfortunately the replacement vehicle I bought (it wasn't obvious at first) had a suspect blown head gasket , I thought the slight oil in the coolant was due to lack of maintenance/servicing by the previous owner & the broken seals on the oil cooler - there were no other head failure gasket symptoms . Also a co2 head tester test showed negative to head gasket issues.6 months after the purchase, the oil management light came on. Diagnostics showed cylinder 2 misfiring. I replaced all the spark plus & ignition coils, the light disappeared for a day , but came back again. My local garage took out the spark plug to cylinder 2 & used some sort of Otoscope to peer into the cylinder and saw coolant in there. He recommended K-seal. I read reviews and results seem to be 50/50, (I presume it depends on the seriousness of the gasket damage, how successful this treatment will be) . But for my Nissan Xtrail 2.5 litre Petrol engine this worked a treat. No vibrating when i started the car, the car ran smoothly. Whether K-Seal would last for a long time, I cant say, I had a road trip planned and wasnt going to risk it, but definitely as a stop gap till i got another car, this worked brilliantly. Its a gamble, but even for the price (£32) I would definitely sue this product again as a stop gab or to get me out of a tricky situation ie getting home rather than being stranded. As for the long term issues with having this in your engine, some say its ok, some say its not great for the cooler system, but for an older car my feeling would be 'why not use it, especially as a stop gab.

Made it worse, bought it knowing won't do much but said to try it, think is good for small leaks but not head gasket pressurising, not cheap either.