How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Robert Your Own Question
Robert, UK Qualified Car Technician
Category: Car
Satisfied Customers: 4716
Experience:  Fully qualified / self employed garage technician in the UK
Type Your Car Question Here...
Robert is online now

huge smoke from exahust when driving along doing over 30mph

This answer was rated:

huge smoke from exahust when driving along doing over 30mph with a strange noise.
The van is citroen dispatch 2.0 hdi enterprise diesel 2005 reg, what could be the problem?


Hopefully i can help..

Can you describe if possible what sort of noise your experiancing or hearing?

What colour is the smoke your seeing?

Have you had any recent work carried out on the Vehicle etc?

Customer: replied 3 years ago.


The noise is like air leaking through the exhaust.

The colour of the smoke is black

No I just bought it

Does that help?

Hi..there thanks for your reply.. the sounds of your description if this is hissing noise under throttle..then its sounds like you have leak or tear in the intake/intercooler system - usually the first places to check would be the intake system pipe work circuit ie:- starting off from the air filter checking its clean and follow all the way checking for any possible restrictions /tears or small holes in the pipe work leaks - so in effect you need to follow all the pipe work from airfilter past the air flow meter upto the turbo unit then around the large pipe work as per the intercooler circuit until you reach the intake manifold,you need to check each of the hoses/pipes aswell as ensuring they are properly connected carefully for holes tears as any tear in say an intercooler pipe work can often/will cause black smoke and power loss that has to be first obvious areas to check here..if you can hear the air leak under throttle or even at idel with the bonnet up - then you need to follow and locate the source as to where its coming from then make checks accordingly - sometimes if its just split in the rubber hose you can use a temp measure duck tape to seal the tear.until as such time you can replace the hose "if" thats whats gone here....but as above that will have to be one of the first checks to make from here..I do hope this helps...if you need to ask anything else or include anything further then please just continue before you rate

Customer: replied 3 years ago.

you don't actually hear any noise or see any smoke until you start driving the van doing about 35 mph. Each time you press the Gas

that is when you hear the noise and see the smoke, when you take your foot off the Gas it stops making the noise and the smoke stops

coming out. When the van is stationary and the engine is running you don't hear any noise or see any smoke.

Hope this gives you a clearer picture?


Hi..there ..

Yes when the engine is under load the turbo will kick in hence when you get the black smoke - thats why its vital or at least one the first areas to inspect is the intercooler.intake circuit on that engine aswell as the air filter condition..if that seems to be in order then the next checks on this would be the EGR valve and its pipe work too aswell as the turbo unit itself/wastegate actuator sticking..small lever,rod on the turbo and ensure that hasnt stuck or is sticking aswell as for possible restriction in the exhaust system probabaly unlikely..but by the sounds of your description its sound intake.intercooler problem related as per air noises/hissing under load suggests

Robert and other Car Specialists are ready to help you