Xsara HDi uneven smokey start

[SuperCargo23]

Hi guys,
I have a 2002 HDi Xsara hatchback, love it to bits, only its second owner.
Last year a drivers' bow-wave partially waterlogged it and this started a long and as yet unresolved battle to regain rude health.
It has had new injectors, and glowplugs, the turbo was believed to damaged seals to that was changed too. I think i may have had a new EGR fitted (after a year new parts are becoming a blur)
Once started the car is amazing for 160k, a joy to drive but its starting was faultering and smokey after the water, and although the issue eased during the Spring to Summer the smokey 'faultering' has returned, maybe co-incidentally with the colder weather.

It regains all four pots running after maybe 45 seconds or so then it runs like a 3 yr old, but the cold start persists.
Do any of these symptoms sound familiar ? Have you had them ? Do you have any tips where i should look now please ?

Thanks in advance.
Ian

[Hell Razor5543]

Hi, and to the Forum. The main question to be asked is what colour is the smoke? Black suggests poor air intake (as this is caused by poor fuel combustion), blue indicates oil is being burnt, while white could mean there is water in the system.

[CitroJim]

As James says... Black is a lack of oxygen leading to incomplete combustion due often to a blocked air filter, a choked intercooler, squashed, constricted turbo air hoses or a seized turbo...

White smoke however usually means incomplete combustion due to lack of heat - the white being pure, well-atomised unburned diesel fuel vapour... This can be a result of low compression often due to a leaky valve or failing piston ring seal...

Low compression will result in a lack of heat to ignite the injected diesel and hence incomplete combustion. It does not take much of a loss of compression to affect cold starting...

It'll often appear to resolve as the engine gets to operating temperature...

I'd hazard a guess you have a very slightly bent/damaged valve as a result of your bow-wave adventure or possibly a seized hydraulic tappet holding a valve just off its seat when cold..

Some older XUD engines exhibited a similar fault through having too tight valve clearances after years of wear and when stone-cold holding valves off their seats and reducing compression... A quirk or the XUD (and indeed the HDi) is that as the engine warms the engine 'grows' and valve clearances open up, thus 'curing' the fault...

As James says, blue smoke is oil being burned...

[SuperCargo23]

Guys,

Thanks for the input, sorry its been a number of weeks since posting - life has got in the way.
Colour of the smoke, hmm white-ish i guess, the sensation is like a petrol engine misfire.

It has had new injectors, glow plugs and relay among other bits, and the starting issue has no change whether it is run to the full glow plug time or not. The compression tests didnt reveal anything out of the ordinary, certainly nothing that would guide my regular mechanic in the direction of rings or valves, much of what has been replaced had been done on the basis of best practice and service experience. Unfortunately while the new bits have certainly revitalised my little car, the starting issue remains.

Mindful of the amount of use my little Citroen now gets, I think i will have to cope with the grumpy motor syndrome for the sake of marital harmony

Many thanks all

Ian

[admiral51]

Long shot but how about the starter motor?
We are talking about a 20 year old car. Ok in warmer weather but colder weather and whiteish smoke. Is it not spinning fast enough in colder weather so unburnt fuel is getting thrown out of the exhaust?
99% of members know i am no mechanic but just trying to join up the dots

Colin

[moizeau]

Egr for me, does it smell of unburnt diesel? Can be tested with Diag

[liquidhandwash]

Maybe a slightly blown head gasket, water gets into a cylinder after sitting overnight. also, give a whitish smoke more like steam.

[wheeler]

Egr for me, does it smell of unburnt diesel? Can be tested with Diag

The EGR valve is mechanical on this engine so you cant really test it properly with diag, only the electrovalve can be actuated. You could rule out an EGR problem by blanking it off (just for test purposes).
Also check the vacuum operated throttle butterfly in the intake, disconnect & plug the vacuum pipe on it to rule this out too.