White Smoke
 

I’m sure my car doesn’t want to be MOT’d.
Latest problem that has started today for no reason.
The car has started to produce white smoke when ticking over and when under power.
Cars only done 20 miles is 4 months and has just under 94k on it.
Any ideas as to what is causing it. I’ve tried getting it to temp and running it at fast idle for 15 mins but no change.
The crankcase filter was changed less than 4k ago along with fresh oil and the MAF has always been disconnected since I got the car 21 months ago.
Car is a manual CDTi with a EGR bypass, DeCat and a 160 map.

I'm no expert but white smoke is usually a sign of unburnt diesel so possibly an injector issue.. I'm sure one of the tech guys will be along soon to say I'm wrong:D:D

Might well be a worn out injector, worst case is water entering the combustion chamber.

Get it on a t4 and monitor the injectors.

seal inside the turbo or seals attached to the turbo or from the MAF pipe?

Try drilling a 3mm hole at the lowest point of the back silencer box. When not run often, condensation accumulates there and can take ages to evaporate. The hole can be plugged with a self tapping screw and a dab of exhaust sealant for the MOT. It also allows the water to escape if left out and cuts the internal rotting of the box. This may not be your problem but if you are not losing coolant, it could well be.;)

Black smoke isn't unburnt fuel it is due to poor and incomplete combustion of the derv in the combustion chamber due to many factors, basically incorrect fuel to air ratio,( excess fuel or insufficient air ) seen often on a turbo diesel when the pedal is floored and an initial puff of black smoke occurs momentarily till the turbo spools up and the correct fuel to air ratio is attained



White smoke on the other hand, not steam, is caused by raw fuel, i.e. unburnt fuel coming out of the exhaust, usually seen at first cold start on a worn engine or one where the heater plugs are u/s, again due to many causes, basically ignition temperature hasn't been reached in the combustion chambers and the atomised, unburnt fuel comes out of the exhaust with a prominent derv smell.


Blue hazy smoke obviously oil being burnt for various reasons.


Steam, obviously from water either in the fuel, coolant leak into combustion chambers, or especially with short journeys and a long time between journeys, as has been mentioned, a build up of water in the exhaust system which will need a good 20 or so miles fast run to get the full length of the system hot enough to boil the water off.


White and blue smoke and steam can look similar, a quick clue is that steam dissipates in the air quickly, blue smoke lingers with a smell of burning oil and white smoke lingers with a smell of derv.


When you say " The car has started to produce white smoke when ticking over and when under power."


On a hot engine white smoke from unburnt fuel wouldn't be expected to be seen and if fuel was not being burn't in a particular cylinder a consequent loss of power would be expected.


The causes of any of the above are many and varied so the first line of investigation is to determine if what you are seeing is from oil or water.


An exhaust gas test may show up some clues.

If you haven't already done it Rob try a bottle of injector cleaner - Forte is good stuff. Have had the same problem on two M47R engines and it sorted them both.

Just had a thought.
Would old diesel cause white smoke.
Ie, I've not put fuel in the car since August last year

I've always read smoke as follows:-
White smoke = steam
Black smoke = unburned fuel
Blue smoke = burned oil
:shrug: