Hello all, this is my first post and actually my first time using a forum of any sort. I own a RRS 2010 AB 5.0. Had for 4 years+ now 145,000 miles, changed nearly everything that typically goes on these (SuperCharger, Active Anti roll bars - front and back, exhaust, cats - both, air height compressor, and to cap it all off replaced the engine - reconditioned from up north). It felt like a new car for the first 15,000 miles (around 5 months). Then a sudden overheat this past Sunday (apparently due to a failed sensor as told by the garage) - pulled over straight away. Tow to the house. Tow to the garage on Monday. Told today that the replacement water release sensor (that failed in an off position) did not fix the issue and completed a sniffer test (not sure to take that as conclusive), suggested to pour down some sealant in the morning and hope for the best. At this point I am at a loss beyond anything I have ever imagined and or experienced. Anyone had the same issues here? Did the sealant work? I am not looking to patch it up and sell it. It would be wrong to give a ticking time bomb like that to anyone... I may have to park it for a while to raise some funds (again). Will the heads have to come off? Anyone know how to get this done affordably? At what point do you make the decision to replace (again) instead of fixing - not knowing to what extent the rat-hole reaches based on the damage done to the rest of the engine from the overhear? Is it really a one and done with these engines? Cost estimates? Time out of action?
When I eventually get back above water, I will do some posts about the initial replacement engine that cost the thick end of £12k (10k engine + 4k labor) got back 2k back for the dead engine that had a catastrophic failure. (a new engine from LR would have set back £15k alone)... Nice to meet everyone and hope to hear some feedback.

Update! Picked up cherished car today... to my shock the magic fugazzi sealant has worked some magic! She did not overheat! Think it was steel seal, or something like that... I know it is a band-aid on a major wound - but the garage swear by this stuff and past “repairs” have gone on to have a full life... I coasted her home the 30 miles from the garage... about 2 miles from home opened her up to see if she could handle the preferred driving style... didn’t miss a heartbeat. Been advised not to flush this stuff out at all as it continues to circulate. Advice is if she overheats again to assume that is engine done... Day 1 with her back and so far so good... under no false illusions that I will likely need a new engine at some point in the future....

So bad news! She overheated today and back in the garage... guess the fix was very short lived... went after about 25 mile open road journey... I tried t heating and it was not blowing hot. Right after it started to overheat. Garage suggest that there may be an air block somewhere- imo likely caused by the sealant... looks like the heads will have to come off... hope there is not more damage to the rest of the engine or all will be in vein for a dead duck engine now twice overheated (but parked up right away). Any way to tell how much damage been done to the rest without getting knee deep? Thanks. Lesson would be to not try the steel seal.

Unluckly, but temp repairs dont fix the problem hope its not to costly to repair.

These "magic" potions never work. Looks like you have spent a lot on it. I would be looking for another garage to do the work if that was their solution. Get a compression test done which will tell you what head it is & hopefully its only the head gasket.
Get that gunk flushed out as it may start clogging the waterways in future. Good luck.

I take it they checked/replaced the thermostat