Good day you who know way more than I, your opinions on this. On a recent jaunt to Scotland my '06 L322 TDV8 3.6 developed what I thought was a slipping alternator belt, got worse if the headlights were on. During the holiday it got worse tried to find a local garage in Oban to fix it but no-one wanted to know, it got worse, began to judder and misfire when accelerating to overtake another vehicle black smoke and a high pitched whistle as well, I resorted to driving like Miss Daisy and managed to finish the holiday and get home. Fearing turbo(s) I booked it in to my local LR specialist and was informed that I did have a badly slipping belt but the cause of the power loss/smoke was the exhaust manifold separating from the head, engine out job! Anyone heard of this, the guy reckons it is a known although rare problem with the 3.6

Are there any broken exhaust studs? Are you confident in their diagnosis? sounds more like a split inlet manifold to me - to prove either way, a smoke test will be the best way forward. The exhaust manifold can be changed in situ (assuming it's the causal part and not the gasket or the inlet manifold) but if there are any broken studs, these can be easier dealt with by taking the engine out (possibly they are pre-empting broken studs) which would cost more in labour as you've spent a lot of time taking the ex. manifold off 'in situ'.
It's a difficult cost balancing act but you really, really need to be 100% sure of the causal part first.

Thanks for your reply, It's at the hands of the garage now, I took it in yesterday and had THE phone call from hell, engine out job. Literally just had a call from them, replaced 4 broken studs and the gaskets all good now - hopefully. Jeez, L322 ownership has it's moments!

It's likely to be a broken stud(s) allowing a venturi to develop through/around the gasket, causing it to break up. The studs can and do break because the manifolds warp - did they check it?

It was broken studs, 4 to be exact, 2 came out easily, 2 broke off so close that they had to be drilled out and re-tapped, head face checked and found good and flat, all new gaskets. Should be good to go.

Were the matching studs on the other side also replaced even though they weren't broken? My brother had to remove the body of his 3.6 RRS a few months later to replace the matching studs on the other side.

That's a good question, they had the engine out so I'm hoping they would have resolved all issues.

I was surprised that my brother didn't replace all studs both sides when fixing the first lot.

Both sides were done and mating faces levelled, new gaskets on the manifolds and all pipework joints for want of a better description.

Excellent!

If the repairer did that without prompting, then they know their stuff and did you a favour (albeit one you paid for), well worth giving them your business IMO

I found them by accident, we were looking for a new car and it was on route. Called in on spec. re. Engine Management Fault, local guys at a loss, these guys straight out with the diag found the fault, booked in and fixed within 2 days and they didn't charge for the diag session. Been going there ever since for all my L322 woes.