xmexclusive wrote:
I would put the 4HP20 median point somewhere between 80k and 120k.
Of the three that I've rebuilt John, they were at 141,000, 159,000 and 171,000. Two of the three had well and truly thrown their toys and the third was caught just before it thought about doing the same...
Given the HP18 has a fairly fine mesh filter there should be no intrinsic reason why doing an oil change should uproot any sludge which then goes on to foul the valve block. The oil in mine was pretty awful and a change has done wonders for the overall functioning of the 'box.
I'd agree though, when paying top money for any auto a verifiable record of regular maintenance is essential. I have offered this opinion when asked to value V6 Xantias. If they are knocking on 150,000 miles and have no records of a gearbox recondition and cambelt and waterpump changes then quite frankly they're worth more weighed-in than they are as a viable car unless you want to start spending a small fortune... Regrettably the same applies to a late S2 V6 XM but then because of their rarity they are actually worth spending all the time and money on to get them sorted.