bad exhaust fumes at front!

[realestate]

2006 vectra 1.9 cdti 120, now and again, especially when idling at lights, plumes of embarrassing exhaust smoke pour from under the bonnet, out through under the wings, how can this be? recent mot, no exhaust leaks, is their a part / valve that can open and do this? I have tried to look from where it comes but just cannot breath the fumes. Then goes all normal and then it repeats, a passing mechanic shouted, hey mate, that should be coming out the rear! any ideas?

[northpole]

mate if it smokes that badly you should be able to find traces of soot where it leaks when the engine is cold. I guess it could be a crack somewhere around the egr system or the start of the exhaust flexi leaking.

[horaa]

You could also try and see for oil leak that drips on exhaust. Another question is: are you sure it's exhaust smell? It can also be coolant...

[realestate]

well from replies it appears that there is no device which can release exhaust fumes up front, I am going to check the new flexi that was fitted when i bought car, although just sailed through mot, as exhaust fumes appear up front on regen, also do the cleaning jobs that appear on you tube.
I read that the ecu will do only so many regens....hard to believe but is this true! what you supposed to do then, scrap it and buy another car!!

[northpole]

well from replies it appears that there is no device which can release exhaust fumes up front, I am going to check the new flexi that was fitted when i bought car, although just sailed through mot, as exhaust fumes appear up front on regen, also do the cleaning jobs that appear on you tube.
I read that the ecu will do only so many regens....hard to believe but is this true! what you supposed to do then, scrap it and buy another car!!

Simple the dpf is a device that just like a catalytic converter only last for a certain amount of time... than it either needs cleaning or replacing. And from what you just stated you should investigate if the dpf pipes connections are sealed right. they are probably leaking but so minimal it's not noticeable when the engine runs, but clearly visible when the regen kicks in (a regen means the DPF starts burning all soot deposits off)

[beavor-bob]

If there is an oil cooler on your car, that can give a horrible stink.

[northpole]

yeah a stink is different from having exhaust fumes coming from the engine bay... he must have a crack/leak somewhere.

[realestate]

yeah a stink is different from having exhaust fumes coming from the engine bay... he must have a crack/leak somewhere.

I love my 1.9 120 vectra estate, came with massive service history! why because it drives like a new car, no bangs, no rattles, sweet gear change, I could go on! and this is at 186000 miles.

today I got under and checked out the ten month old flexible joint which came with the car, which was protected with exhaust webbing and sure enough there was the black soot culprit!...replies above said there was no device that could pump exhaust out front, so top marks to you.

The engine is sweet and pulls like a train.

I gave up half a day to clean out the EGR, throttle body which came complete with swimming pool of black oil (but i assume this is not affected by the oil?) and the MAP sensor. I did this because a few days ago the injector pre-heat light started flashing, handbook pointed to DPF.

The light after cleaning still flashed, I wasn't surprised I just felt better after cleaning out the crud, but today I was surprised because the flashing injector light stopped!!

However the engine seems to want to do regen every ten miles and is embarrassing to say the least.

so now I have questions to raise, and I hope the answers will help other people with a similar problem.

Q, was it just a coincidence the the injector pre-heat light went out after cleaning parts? or anyone know why it should go out again?
Q, does the exhaust leak have an effect in some way on the ECU or DPF readings.
Q, would the fact the exhaust has a leak cause recurring regen problems?
Q, is it true it can only regen so many times.
Q, if so, can a garage force a regen?
Q, and finally would buying a new DPF be the answer to my prayers!

[Propeller]

Q2: sure, the leak influences the measured backpressure BEFORE the DPF converter. IF your car is equipped with a lambda probe, it will also interfere its readings.
Q3: the regen is initiated by the ECU via comparing pressure BEFORE and AFTER the DPF. In ECUs language: "If there is a difference X there must be a soot Y inside the DPF." So if Y is over a programmed value the ECU will start a regen. also see Q2
Q4: it only starts regen when various options are meet: temperature, rpms, IQ.. it will abort regens, when parameters are no longer in desired condition and start again when values are OK for regen
Q5: they can force a regen
Q6: it will be nice to know how much the saturation of the DPF is.

greets
Andre

[realestate]

Q2: sure, the leak influences the measured backpressure BEFORE the DPF converter. IF your car is equipped with a lambda probe, it will also interfere its readings.
Q3: the regen is initiated by the ECU via comparing pressure BEFORE and AFTER the DPF. In ECUs language: "If there is a difference X there must be a soot Y inside the DPF." So if Y is over a programmed value the ECU will start a regen. also see Q2
Q4: it only starts regen when various options are meet: temperature, rpms, IQ.. it will abort regens, when parameters are no longer in desired condition and start again when values are OK for regen
Q5: they can force a regen
Q6: it will be nice to know how much the saturation of the DPF is.

greets
Andre

Thankyou for your valued reply.

My joy was short lived as the flashing pre-heat light came back on today!

My answer to my problem surely is to fit a new DPF and new downpipe with flex....cheaper than a new car!
anyone agree?