Xantia Diesel Lost Power and Smoking like hell

Mandrake · Post by **Mandrake** » 02 Feb 2006, 00:20

If all the other things check out ok, it could be the turbo seizing up

I had a faulty turbo on my old Daihatsu Charade once (admitedly a petrol engine, but...) and at first it would only seize occasionally but whenever it did it would totally kill the performance and even with full throttle it wouldn't go over 3000 rpm even in a low gear because a seized turbo (depending on the design of the impellers) blocks the flow of both inlet air and exhaust, choking the motor.

As well as that it used a boost pressure sensor to open the second carburettor stage - so no boost, no second carburettor stage.

I think jeremy has probably hit the nail on the head - if the injection fueling at lower revs is controlled by the engine revs, but beyond a certain rpm you only get more fueling if boost pressure is detected - no boost, no extra fueling, so you can't get past a certain rpm.

Lots of smoke (and using a lot of oil) could be a sign of a failed seal in the turbo as stevieb says, but it could also be something else.

In any case, if all the obvious things like the filter, and the pipes to the turbo are checked its not sounding good....

One question nobody seems to have asked yet is has the engine always been idled for the turbo cool down period before turning off ? Failing to do this on a regular basis is a sure way to kill the bearings and seals of a turbo...

Regards,
Simon

Mandrake · Post by **Mandrake** » 02 Feb 2006, 00:31

jeremy wrote:Its not the small hose to the extra fuel device on the injection pump. I agree that this causes a considerable loss of power as basically it instantly converts the engine to a non-turbo but it cannot cause smoking.

It's worse performance than a non turboed model if the hose comes off because if as you said in a previous reply it relies on the boost pressure to trigger extra fueling the fueling will be severely restricted...

I agree that a failed turbo oil seal can cause smoking - in which case it will probably be the characteristic engine oil blue. This is not a common problem with Citroens and also would not cause a loss of power and by now would be causing a very considerable loss of engine oil.

If the seal is leaking its likely that the bearings are damaged as well, and if its leaking a lot of oil the turbo could easily be seizing, which will kill the performance dead as per my previous post...

Regards,
Simon

JohnCKL · Post by **JohnCKL** » 02 Feb 2006, 01:04

Go for the simple solution first, check all the turbo hoses from airbox to turbo to intercooler to engine, make sure no loose ends sticking out of place, no obstruction and tighten the clamps.

Post by **Peter.N.** » 02 Feb 2006, 10:49

Have you tried what I suggested, disconnecting the air inlet hose from the manifold, that will tell you a lot. If the smoke stops you have a blockage or faulty turbo, if it doesn't it must be timing or injector/s. Also, if the turbo is working, you should feel a strong draft from the end of the disconnected pipe when you rev the engine. When you disconnect the pipe, check inside the manifold that it isn't full of carbon from the EGR.

stevieb · Post by **stevieb** » 02 Feb 2006, 17:06

Depending on what side the oil seal has gone, a turbo oil seal failure might result in either blue or white smoke.

If it's inlet, it'll burn off blue. If it's the outlet side, then it'll vapourise in the exhaust and turn white instead. Here speaks the voice of experience.

What colour is your smoke?

If it's black, then it's unburned diesel, and is likely to be an air intake problem (possibly a seizing/seized turbo as Mandrake said), or an over fuelling problem. But over fuelling wouldn't limit the revs, at least not without the temperature shooting sky high at the same time...

Post by **Peter.N.** » 02 Feb 2006, 17:30

That's why I asked him what colour it was. I dare say he will get back to us eventually.

bman · Post by **bman** » 02 Feb 2006, 20:15

sorry for being useless i've been busy with my vr6 tonight, will pull the hose of the inlet in a bit.... not to sure what colour the smoke is tbh thinkin whte but not sure

bman · Post by **bman** » 02 Feb 2006, 20:56

right just went and had a fiddle pulled the hose off the manifold and rev'd uengine.... the is air cominf from the turbo and there is little/no smoke so took it for a drive no power at all as i guess is expected.... pretty sure its white smoke

bman · Post by **bman** » 02 Feb 2006, 20:57

oh and manifold is not oily maybe a little sooty but its v dark

AndersDK · Post by **AndersDK** » 02 Feb 2006, 21:18

Good on ya 8)

White smoke is either evapourated diesel fuel or engine oil.
Now try hold a cloth aginst the exhaust pipe. If it smells like diesel - unburnt fuel. If it smells like oil and leaves very greasy tracks on glass surface its engine oil from turbo hot side - failing oil seal.

If its neither - then its coolant from a busted HG or cracked CH.

bman · Post by **bman** » 02 Feb 2006, 21:25

it does smell dieselly and it aint oily

jeremy · Post by **jeremy** » 02 Feb 2006, 22:30

Just to recap a little - and please correct me as I haven't re-read the thread.

Engine starts well
Turbo's working
Inlet doesn't seem excessively gummed up?
White diesel smelling smoke from exhaust.

If the engine starts its a reasonable assumption that the engine is in reasonable mechanical order. If the compression was low it would be difficult to start.

If the injectors were shot I'd say much the same - it would be difficult to start and would run very slowly immediately after start. At least that's what happened to my TD BX. In fact the cold start advance was working properly but no increase in speed was detectable and it was actually so slow that it was hunting when cold. The smoke was not significant but enough to worry the MOT man.

Its not glowplugs - as its the same when hot.

So what's left?

Injection pump - probably ok as it starts.

Pump timing? - could be drive - ie cambelt fitted incorrectly, pulley loose and eating the key?

Now lets see what everyone else says?

Post by **Peter.N.** » 02 Feb 2006, 23:01

If it starts OK that would seem to rule out timing, if an injector was stuck open it would be smoking but knocking like a goodun. You did mention that it was using a lot of oil, if the smoke is blue, could be a turbo seal, but the turbo seems to be working ok and yet there is no power. Could be oil bypassing the pistons due to wear, but then you wouldnt think it would start. Clutching at straws here. When you start it, does it start on all four cylinders immediatly?

bman · Post by **bman** » 02 Feb 2006, 23:37

it starts on all 4 straight after the glow plug light goes out im havin a go at straws now im thinking maybe the cat's blocked? causing too much back pressure ... but then why all the smoke?

Post by **Peter.N.** » 02 Feb 2006, 23:43

That's whats puzzling me! Could be of course that the cats blocked and you have a leaking seal. Ah! I wonder if the back pressure on the turbo is causing the oil leak. The only thing you can do is try disconnecting the exhaust.