Having just done crankshaft oils seal (Huge and sh**ty job) I was wondering if anyone out there knows why 3rd gens have auto tensioner. The TS V6 was a lot less complicated (no expensive auto tensioner, no tensioner to fail ,easier to replace cambelt). I can see no advantage to owners....anyone?

I probably would not tackle a car more sophisticated that my TJ (fortunately 380 is as easy as TJ). I would hate to do twin cam (per bank) motor or variable valve timing etc. So my next car will probably not be an Aurion, but is likely to be 380 or TL/TW.

Right now I am in favour of timing chains......my wife's Nissan pulsar is coming up to 100 000km and I don't have to worry about replacing a belt.

i would imagine, the auto tensioner is there for when the belt has warmed up and its stretched somewhat, to keep everything spot on still. im sure il be corrected if my idea of why there is a auto tensioner is wrong.
also over time (say the 100oookm of its lifespan - the belt will have stretched too.

timing chains are good, but tend to be noisy iv found with some of my old cars (if not cared for correctly by previous owners / current owner lol)

Is this tensioner the item that causes that much-loathed Magna rattle/groaning sound at 1100rpm?

Ummmm,

I gather the old Astron 2.6 engines had a fairly simple balance-chain adjuster - BUT BUT BUT they chewed through teh balance-shaft chain quickly if owners/servicing didn't keep taking up the slack (ie: being too slack in attitude to do the adjustment of belt-slackness LOL).
End-result some owners not happy with a rattly engine and some rattly engines died due to complete slackness (ie defective human element in servicing of car).

Timing BELT won't rattle and piss-off owners, and auto-tensioner helps belt longevity/reliability by maintaining correct tension.

I'm overdue to replace a timing belt on my TJ, and it won't be very long either before teh KJ will be due. I'm a bit daunted by the belt-tensioning procedure, and the apparent need for a special service tool to correctly tension a new timing belt. I'm putting it off...... I'd whip-in and do the job, but for the dire advice about needing the tool to get tension correct. I'm not sure if this is a Mitsi anomaly, or whether timing belts for most vehicles are equally finicky about the belt-tension procedure.

the apparent need for a special service tool to correctly tension a new timing belt.

You're not going to like how much it costs - EMD998767 - $179.

Yep, your Damn Right!!! Not liking that price-ticket at all.

I may even have to donate some Spendoolies to a mechanic, dammit...... get the job done right, by someone who has a clue (as opposed to me LOL).

Is this tensioner the item that causes that much-loathed Magna rattle/groaning sound at 1100rpm?

My tippy Tj vr-x makes this sounds you speak of low down just as you take off sometimes, is this a common thing?

I was a bit worried about it.

I did the belt in my VRX AWD a while ago and no special tools required to tension it. Just remove the tensioner, compress it in a vice and put a nail in it to lock it down. When refitted, remove the nail and it auto tensions. Rotate the crank and check its all OK and done. Biggest trick was removing the bottom pulley for which I made a holder that clamps the pulley to the chassis while undoing and retorquing. The top engine mount is a fiddly pain, it should be 2 piece.

Steve