XUD9 vs DW8 discussion

[kenbw2]

Might be opening a can of worms here, but I'm interested in what the opinions are around the XUD9 and DW8.

I know the DW8 is a the same bottom end as the XUD9, and both are pretty much the same capacity and horsepower.

Specific points I'm thinking are:

- Performance
- MPG
- Longevity/durability
- Noise
- Simplicity of repair

Discuss...

[elma]

Xud9 simpler, better and feels more powerful.
Dw8 same thing, better emissions, a few extra bits to go wrong.
My choice xud9 every time, the older the better.

[CitroJim]

Xud9 simpler, better and feels more powerful.
Dw8 same thing, better emissions, a few extra bits to go wrong.
My choice xud9 every time, the older the better.

As an XUD9 driver and having experienced loads of them over the years, I fully agree with James...

[kenbw2]

Same here. I've had 2 XUDs and never a problem with either engine - until the timing belt snapped on one at almost 250k miles

Wondering what to make of my new(!) DW8 one

[Old-Guy]

Xud9 simpler, better and feels more powerful.
Dw8 same thing, better emissions, a few extra bits to go wrong.
My choice xud9 every time, the older the better.

Agreed. Pre-1996, no EGR and no engine ECU so entirely mechanical (Bosch) injection system; only use for a Lexia is to find which ABS wheel sensor is causing the ABS to go into fault mode (light on, no ABS). Oh, and one extra pony-power too.

[demag]

The only thing I noticed was boot the xud and watch the smoke screen but the DW8 wasn't so bad.

Sent from my Wileyfox Swift using Tapatalk

[Old-Guy]

The only times I ever saw smoke visible in the (XUD) Xantia's mirrors was briefly after booting it up Haldon Hill (A38 beyond Exeter) after gently cruising down the M5; just a bit of soot on the turbine taking light as soon as the exhaust gets really hot. No problems passing the emissions smoke test - even at age 21 and a mere 130k.

[elma]

They're all a bit different. If they do good runs and have a short idle before being turned off they tend not to smoke. I've only had one smokey one and that was because I had a piston ring fail.

[CitroJim]

Mine runs like a clock, very frugal and powerful but never smokes, even with the biggest provocations...

[white exec]

Our BX19 NA never smoked, even when provoked, and sailed though smoke test at MoT time.
A fabulous engine, if you look after the cooling system. (BX XUD HG issues were largely due to lack of a proper header tank, IMO. We fitted one, and then had another 130k miles, trouble-free, even towing 850kg of caravan all over Europe.)

[CitroJim]

if you look after the cooling system.

Precisely, that and regular cambelt replacements are essential to a long XUD life Chris, along with frequent oil changes...

They then go on reliably for ever.. Mine's on 208K and as fresh as a daisy still...

[ekjdm14]

XUD every time. I can't speak for the 97k blown up lump, how it was treated & what caused the failure are unknown to me although the coolant was good and literally zero waterway corrosion internally, but the c.150k replacement NA passed emissions with a reading of 0.17 IIRC (permissible 1.51) and even fully loaded and foot to the floor to maintain speed up hills on the way back from Scotland I've failed to glimpse any smoke behind us. Only time I see anything from the exhaust is from a cold start it puffs a little black out. I believe one glow plug may have gone lame since installation though so even that may vanish soon!

In comparison there's one or two DW engined 206s round here and they do smoke. not much, but more than the Xant' & with less weight to haul too...
A well looked after XUD will just run & run, ours must have been pretty well cared for since after I changed the oil 500miles ago the oil on the dipstick is still translucent whereas on most diesels I've serviced the oil is black on the stick again as soon as the engine's been run for a few minutes.

I would also hazard a guess that if a well looked after 23 year old XUD was tested alongside an average DW8 the older engine would be cleaner running despite the EGR and all that jazz. Not that the DW8 is a bad engine, nothing with XU roots could be, but for my money I'd prefer a good XUD over an average DW8 any day.

And for the record, Lexia would be totally useless on our Xantia as we don't even have ABS! Not sure it'd talk to the airbag either since that has it's controller in the 'wheel & just gets an ignition +ve from the car AFAIK...

[chinkostu]

Not a fan of the DW8, essentially a xud with asthma. Egr sticks open or the needle lift shats it and then they're a pig to get going right. Mine was still tank volume after various fixes, had to unplug vac to egr as it made it kangaroo

[white exec]

Did I imagine it, or hasn't been reported that diesel emissions improve as well-maintained engines put on significant mileage?

[ekjdm14]

Did I imagine it, or hasn't been reported that diesel emissions improve as well-maintained engines put on significant mileage?

Probably true in the case of the XUD, and likely other known long-lived diesel lumps like the Merc 5 pots and the like since with age & mileage they loosen up considerably and the components are only just fully "run in" by 100k or so. Makes sense that as that process happens the emissions would fall.