If its EDK's almera then I think he's done quite a bit to that lump to make sure it doesnt spit its dummy out.

To the bottom end he has not done anything.

Must admit I dont know the full details of what they have done.

But then again the almera is a much lighter vehicle than the xtrail and not 4 wheel drive which must be a factor in keeping things together better.

Bolts normally only brake when there is a high load on them. Tuning will not add to the load, but revving the engine higher will, as it is stretching them not compressing them. I read on here that someone was saying that there engine started to go flat when revving past 4,500 revs. No wonder they brake. Mine is tuned by Celtic Tuning and pulls from 1,500 revs, and don't need to go past 3,000 to be doing80 up a slip road onto the M way.

Ours is completely standard but I make a point of giving it 4500 (or maybe a bit more) revs once a month on a wide open throttle. I think it's important to use an engine over its whole operating envelope to avoid thinks like sticking turbo variable vanes or sooted-up EGR and inlet manifold.

If you look at the pictures on my thread, then you can see what exhaust gas and oil can do. The box shaped inlet are narrower and they where so clogged that a screw driver would not pass thru. I scraped like 4 hours.
So we need revs, and no EGR.

Ours has done just over 100,000 miles now - almost all of it on supermarket fuel, and the EGR valve (and presumably inlet manifaold) is as clean as a whistle. Just a very light coating of soot if you wipre your finger round the inside. I'm pretty certain they're fine as long as they see the occasional patch of high temperature operation?