Hi all, my dear old ML seems to be unwell. About a week ago it went into limp mode shortly after starting on my journey (about a mile in). I turned round and drove home then re started the engine and all seemed okay. I made other arrangements that day and didn't drive the car. Next day the same thing happened after almost the same distance but this time I didn't have far to got (about 5 miles) so just drove on. Then when I came back later in the day all seemed fine. Now it all seems a bit random, I can drive the car around for several miles locally (mainly on the flat) and all is fine, but if i get a bit of speed up and climb a hill it goes into limp. Then later in the day I do the return journey (down hill) then theres no problem? My mechanic checked the codes and there was one for the gearbox (which I think is an old one) and apparently one that led him to an air valve (to do with the turbo) sited behind the off side headlight. We also know that the inlet manifold is not in the best shape. The car now has nearly 140,000 miles on the clock and I don't want to waste money guessing at which component to change. It just seems odd that the problem is so intermittent? Does anyone have any thoughts?