hi,
can anyone suggest a possible reason for the following problem with a 1.9 Diesel ZX.....
Car runs OK at town driving speeds. Put it on a motorway and sometimes after a while it starts blowing out clouds of white smoke and continues to accelerate. Pull over and leave it for a few minutes and it drives normally again for a while.
White smoke to me implies excess diesel. Accelerating ditto, which seems to me to indicate that the injector pump is doing something silly.
Is this a fimiliar symptom of a recognised fault, and can anyone suggest what the fault/solution might be?
Thanks
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Black smoke would indicate excess fuel, not white. White smoke could indicate an air leak into the fuel or water vapour in the exhaust. Which injection pump do you have? If its the Lucas (and not a Bosch) then an air leak into the low pressure side of the fuel system could be indicated. The Lucas pump uses the fuel to control the governor inside the pump, if any air gets in it tends to play havoc with this and this could show up in the car accelerating.
Its just a suggestion, but maybe worth checking out.
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Thanks for that. It isn't actually my car, tho' if I can convince myself the problem isn't serious it might be!!!
I spoke to the owner again last night. Apparently the smoke is more grey(ish) with a tinge of blue. That more sounds like its burning oil, and his garage also suggested this to him. It would also explain why it tries to accelerate, if its using the oil as fuel.
I guess the critical question is, how can it draw oil into the engine. I'm thinking most likely is getting in via the breather. Overfull is a possibility to check, but is there anything else (eg. blocked breather/vent etc) which might cause it. I can't imagine its rings etc, as it doesn't smoke on start up, only after being driven at motorway speeds. Its also only done about 110K, and my previous one had bores so good you could almost see the honing marks after 150K. (unfortunately, the head gasket didn't have quite the same longevity!!!)
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I had a similar problem with my mondeo,turned out to be air getting in to the fuel system through fuel filter seal being incorrectly fitted during service. Might be worth changing fuel filter if possible.
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I thought I'd add a bit of extra detail.
I went for a ride in car over weekend, to see the fault for myself. It is fine around town, anything up to 60mph there are no problems. However....
On the M25, after about 5 minutes at 70/75 suddenly a noise like a terminal death rattle. Imagine a case of pinking, after amplification by the Pink Floyd. Accompainied by clouds - and I mean clouds - of white smoke. The sort of screen laid down by a destroyer being chased by a pocket battleship, only in white!
Driver de-clutched (rapidly!) and the revs rose briefly before subsiding to tickover, by which time we had relocated to the hard shoulder. We sat there for a matter of 10 to 20 seconds and then he drove off again, with the car sounding and behaving perfectly normally.
When we stopped I checked oil - all there, water - ditto, crankcase pressure nothing abnormal - a very slight puffing from the filler, but no worse than my car. I wanted him to do it again with the breather pipe removed to see what happened, but he declined due to the time it might take to clean the engine compartment afterwards.
I'm intrigued. I almost (but only almost) wish it were mine so I could get to the bottom of it. I'd love to know what might be the cause. Anyone got any suggestions?
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Sounds like engine oil is being pushed into the intake & being burnt in combustion as extra fuel.
Are you sure the oil level is not over full.
If not why not try re-routing the engine breather into an old plastic bottle to see if :-
1 It collects any oil.
2 It cures the problem.
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