Huge cloud of smoke and engine revs on its own

[Ryanh1008]

Really in need of some help or advice here please

My DPF light came on today, so went on a run on the motorway to try clear it. It didn't come off by the time I stopped, however as I was coming off the motorway when I changed into 3rd I seemed to loose a lot of power, a huge puff of white/grey smoke come from the exhaust and then power returned

I stopped turned the engine off and went in a shop for maybe 10 mins. When I came back out the car wouldn't start, it was just cranking very very slowly

After letting it sit for an other 5 mins, the car started but then ..... after about 100m the car accelerated full throttle on its own, and I was engulfed in smoke from the exhaust pipe

I quickly turned the engine off and give everything a chance to 'settle'. The car then started up fine and I had a very bum twitched 4 mile drive home

The car will start fine now but I've not been back out in it. Does anyone have any idea at all what could have caused this or if there could be something serious wrong?

Thank you!!

[Stevey Y]

1 hour ago, Ryanh1008 said:

Really in need of some help or advice here please

My DPF light came on today, so went on a run on the motorway to try clear it. It didn't come off by the time I stopped, however as I was coming off the motorway when I changed into 3rd I seemed to loose a lot of power, a huge puff of white/grey smoke come from the exhaust and then power returned

I stopped turned the engine off and went in a shop for maybe 10 mins. When I came back out the car wouldn't start, it was just cranking very very slowly

After letting it sit for an other 5 mins, the car started but then ..... after about 100m the car accelerated full throttle on its own, and I was engulfed in smoke from the exhaust pipe

I quickly turned the engine off and give everything a chance to 'settle'. The car then started up fine and I had a very bum twitched 4 mile drive home

The car will start fine now but I've not been back out in it. Does anyone have any idea at all what could have caused this or if there could be something serious wrong?

Thank you!!

Hi without scanning this is just an educated guess, it could well be the throttle body is clogged and the internal butterfly is having a problem finding its operational parameters, but as I said scanning is the only real solution.

Steve.

[cliffcoggin]

Is this the same smokey engine you asked about 20 months ago? If so, what was the solution at that time?

The obvious candidate for the smoke now is the DPF blockage. Whether that is also the cause of the uncontrolled revving seems unlikely. Possibly both problems are symptoms of a more fundamental fault with the engine.

Runaway diesel revving is a serious problem and invariably ends badly, so it needs to be diagnosed and rectified before returning the car to use. I would even go so far as to say the car is dangerous.

[Ryanh1008]

In answer to both previous comments:

The EGR value threw up a fault a month or so ago and was cleaned out of all the crap inside and after that has ran okay. So I doubt that will be blocked already

The previous mention of a smoke engine was coming from the actual engine bay and turned out to be oil burning off from a leak, I can't remember the exact cause

This time it's coming from the exhaust pipe. An other thing to note is the DPF light is starting to become a common thing now and 9 times out of 10 comes on after filling the tank. As it did today 

[cliffcoggin]

What I am wondering, and at the moment it is only speculation, is whether the excess crankcase pressure you reported last year is responsible for the present problem. If the engine is blowing a lot of lubricating oil into the intake manifold it might  explain the slow cranking on the starter motor, the blocking of the DPF, the clouds of smoke, and the runaway engine. Under the right (or perhaps I should say wrong) conditions diesel engines can run on their own lube oil.

What is the mileage of the car? What is the oil consumption? What is the general condition of the engine?

[Ryanh1008]

7 minutes ago, cliffcoggin said:

What I am wondering, and at the moment it is only speculation, is whether the excess crankcase pressure you reported last year is responsible for the present problem. If the engine is blowing a lot of lubricating oil into the intake manifold it might  explain the slow cranking on the starter motor, the blocking of the DPF, the clouds of smoke, and the runaway engine. Under the right (or perhaps I should say wrong) conditions diesel engines can run on their own lube oil.

What is the mileage of the car? What is the oil consumption? What is the general condition of the engine?

I’m on around 103,000 at the moment 

I would say it’s in good condition, we got the car from jct with around 70k on with good service history and I’ve change oil and filters ever since every 10k(ish) .. last change was probably around 91/92k

I’ve never noticed and significant drop in water or oil, but fuel consumption seems to be getting worse recently. I’m not really getting decent mpg for the car and if I do try drive economically if puts the dpf light on 

[cliffcoggin]

Fair enough. In that case I suggest you get some diagnostic tests done as soon as possible.