Citroen XM Forum

robert_e_smart wrote:Autos are fine as long as they are regularly serviced.

Yes indeed and all this entails is regular oil changes and filter cleans which on the 4HP18 is really quite easy. Nothing more involved than an engine oil change.

The 4HP20 used on the late S2 V6 is a different kettle of fish though...

I too can vouce for the 4 speed ZF mechanical auto box.. A mates 2.1 TD auto is now on 223k, and we beleve its all original box with no rebuild.. We change the box oil every 6 k... still drives lovly with smooth changes...

Interestingly, I read about doubts to change the auto oil today (!) especially when it is not known if the oil has been changed regularly in the past. Something about dirt that can come free and get stuck in the brain of the auto box. There is some bad experiences with this apparently but I intend to keep changing the oil regularly.

Captainhaddock raises a good point with unknown box maintenance history.
In my view that makes any high price purchase of a high mileage auto XM a bit of a gamble for the purchaser.
Sadly autobox XM's had a history of box failures from quite low mileages.
I suspect that while many of us can identify some high mileage survivors these will be past the average mileage for failure.
My stab at the median point for the XM 4HP18 box would be somewhere between 120k and 150k.
I would put the 4HP20 median point somewhere between 80k and 120k.

John

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.