xantia 1.9td turbo change

citroenxm · Post by **citroenxm** » 06 Apr 2009, 21:49

The advantages of having a spare car or FEW spare parts lieing about!!

This 207k Xant I got has two methods of starting - if its AS SOON as the light goes out she WILL smoke for a few seconds... grey etc etc HOWEVER, if I leave the plugs a few more seconds AFTER the light goes out, say about another 10 seconds she starts AS GOOD AS 20k!!!!!!

Im happy with that, and wont bother dooing anything untill she gets HARD to start.. Why upset something thats working...

Paul

boeingmech · Post by **boeingmech** » 06 Apr 2009, 21:58

I can understand the heating of the glow plugs twice helping the starting/less smoke, but the smoke I get when I accelerate after it has been ticking over for a while stumps me, especially once it has cleared there is no smoke that I can see from the drivers seat and it drives fine.

Xaccers · Post by **Xaccers** » 06 Apr 2009, 22:04

When Cassy is running on derv, if she stands idling for 5 maybe 10 minutes or more, there's black smoke when she pulls away (after 15 minutes there was a very large cloud of it!)
However on veg, she runs a lot quieter and smoother, and I don't recall seeing any black smoke.
These turbo threads always interest me as I'd rather catch a problem early than lose the turbo (as happened with Sophie, my Laguna II 1.9DCi after about 40K)

Deanxm · Post by **Deanxm** » 06 Apr 2009, 22:06

What happens is at idle the exhaust gas flow is cooler and slower, the oil leaking from the turbo on the exhaust side runs in on idle but is not burnt, when you rev the engine the exhaust becomes hotter and the relativly large amount of oil is boiled off (White smoke) or is burnt off (blue smoke) depending on the amount of oil leaking.
If you take the car on a long run the exhaust stays hot and the oil is burnt as it leaks out in tiny amounts and so is not noticable, until you stop and idle for a while and so it starts again.

D

Deanxm · Post by **Deanxm** » 06 Apr 2009, 22:11

Black smoke is unburnt fuel.
I have run my transit and some Merc and DAF lorries on veg oil and they do run quieter and with less black smoke than when on derv, had to stop though when the diesel price dropped and it became financialy pointless to carry on running them on it.

D

sparky33 · Post by **sparky33** » 06 Apr 2009, 22:11

White smoke is fuel being burned in the exhaust system, you can't boil off oil.

Black smoke is a dirty injection and inlet system

boeingmech · Post by **boeingmech** » 06 Apr 2009, 22:14

Deanxm, thats exactly what i thought hence my first question how easy is it to change the turbo, i was thinking of taking it off then i would possibly see oil on the exhaust side if it is leaking, but as i need the car for work i have nightmares when it comes to undoing nuts and bolts on the exhaust,they are bound to be rusted.

Deanxm · Post by **Deanxm** » 06 Apr 2009, 22:20

White smoke is fuel being burned in the exhaust system, you can't boil off oil.

Black smoke is a dirty injection and inlet system

Black smoke is lack of air or too much fuel, both are basicaly the same thing (too much fuel trying to be burnt with too little air) resulting in incomplete combustion.
and if you pour oil onto a hot surface and dont ignite it (by starving of air like in an exhaust system) you get large quantityies of white smoke.

D

Deanxm · Post by **Deanxm** » 06 Apr 2009, 23:09

The Turbo's are going to be a pain to get off purely because they are down the back of the engine.
I think you will need to have a look at the Haynes book of Jokes, not sure how well they cover this job on the Xant though and ive never done one in this car.
The problem comes when, as you do, the car is needed on a daily basis, but if you could get a loaner for a while all you would need to worry about is if the studs and nuts that hold the turbo on arent rusted into flakey brown ball's

D

citroenxm · Post by **citroenxm** » 07 Apr 2009, 10:06

Dean,

As I said way above, removal is NOT that bad on the XUD, there is NO coolant pipes it disconnect, just oil feed, and it comes out MUCH easyer with the drivers side drive shaft out, and remove it WITH the manifold, theres just 6 nuts then but the studs need removing to make it easyer... by locking two nuts together on each stud to undo it....

Paul

boeingmech · Post by **boeingmech** » 07 Apr 2009, 10:54

I was wondering, if I took the exhaust down pipe off the turbo and if it is leaking oil that side would I not see evidence of it?

Brigsygtt · Post by **Brigsygtt** » 07 Apr 2009, 11:30

The classic symptoms of turbo failure are smoking on overrun, smoking on idle. Even the most knackered turbos don't smoke on acceleration/boost.

Check for play in the turbo shaft. There should be no more than 1-2mm in all directions.

If the turbo is shot you need to find out why it has failed, whether its lack of oil pressure, overboosting due to boost leaks, oil contamination etc. If you change it you don't want to do it again after a couple of thou miles.

Rough running & smoke on startup will not be turbo related imo. Id be looking at the injectors/fuelling. Ive blown a few turbo's up in my time

jgra1 · Post by **jgra1** » 07 Apr 2009, 13:17

I did a 405 TD turbo change a few years ago

agree that upper engine mounting removal is a must

also, I used a scissor jack to help the engine away rom the bulkhead as far as it would go.. then removed inlet manifold and the turbo/ex manifold was easy from then on... I am not sure i ever went under the car.. cant remember..
Job was easy really, and should have taken about 2 hours... but I installed a new turbo unknowingly from an auto, and it was every so slightly different ( exhaust flange about an inch displaced, due to no gearbox linkage rods I think)

75000 does seem very low though..

John

boeingmech · Post by **boeingmech** » 07 Apr 2009, 15:46

just got home and thought i'd try this, engine nice and hot let it tick over for 5 mins and then floor it, big cloud of oily smoke out of the back end, let it tick over for a few secs then held it at 3000rpm got a cloud of smoke then it cleared whilst still holding the revs, let it tick over then floor it got another big cloud of smoke

Deanxm · Post by **Deanxm** » 07 Apr 2009, 21:25

I will admit im no pro but in my experiance it IS very possible that a turbo can fail in this way (i have just replaced one that failed in exactly this way) but, it will not as Brigsygtt has said cause rough running or smoking on start up unless the turbine shaft is jammed solid but you would definatly know if that had happened.

D