Vauxhall Zafira 1.9 CDTi Z19 DTH 2008 - Thick white smoke after 2-3 miles - Fixed #
Posted by George Georgiou on March 10, 2012, 10:05 am
Year of Manufacture *: 2008 Engine Size and Code *: 1.9cdti Z19DTH ( Optional ) Scanner Used: Launch ( Optional) Fault Codes: NONE
This fault has been going on for several weeks and I understand Vauxhall have had a look at the problem and not been able to solve it. To be fair to Vauxhall not sure what level of diagnostics they did or were allowed to do by customer. Also along the way the EGR valve has been replaced ,coolant temp sensor, vehicle oil /filter and air filter replaced with no improvement.
Code scan of engine shows no fault codes. Also the glow plug symbol is flashing indicating the DPF needs regenerating.
The fault happens as follows . Start engine and drive for 2-3 miles , then all of a sudden get really thick white smoke from exhaust . This smoke is definitely unburnt diesel , not steam. If you park the car and leave it idling it continues to belch out smoke. However if you switch off the engine and restart NO MORE SMOKE. Can rev the engine freely and only usual slight diesel puffs evident on WOT. Then drive it a short distance and smoking restarts again.
The Launch shows a MAF delivery of say 26kg/H air flow and the Calculated air flow shows 60kg/H whilst idling and as you rev up the engine the MAF value increases but is always a lot less than the calculated value. The MAF is working , but puts out a frequency based voltage which changes value as engine is revved. However I have no info on what the value should be of the output frequency against different input and at a cost of over £150 I have little reason to change this part in an attempt to get a fix.
Also my Launch is showing DPF filter measurement of 114% , i.e. is this suggesting filter is more than totally blocked? Not sure what this is referring to.
I need to do further diags on Monday and check injectors to ECU control , already done leak offs and all are same average value so not any abnormal leaky injector.
I know there is a software update for the ECU regarding DPF regen according to Autodata and will need to find out from Vauxhall what this is all about , however I have no fault codes to suggest this problem. Also lots of issues with the injector plug no 3 needing replacement due to various issues on this engine.
I suspect the fault may lie with the DPF , perhaps the smoke is a regen starting during the drive? but why does it continue when slowing down and just idling. I thought regens only continue above say 25 mph and it would stop regen if high enough speed not attained. The difficulty is that I would like to take this for a decent run to allow the regen to happen but worried about the amount of smoke and getting stopped as well as the environmental issues.
If not a regen then possible low compression or ECU timing problem to injectors causing misfuelling. But no misfire is detected when smoke starts and engine drives smoothly except for masses of white smoke.
Hopefully somebody out there can point me in the right direction as always any help appreciated.
George
Re: Vauxhall Zafira
Posted by Andy Evans on March 10, 2012, 12:04 pm, in reply to "Vauxhall Zafira" Andrew Evans
Have the injectors been removed?
Re: Vauxhall Zafira
Posted by george ambelas on March 10, 2012, 2:43 pm, in reply to "Vauxhall Zafira" George Ambelas
Hi george it seems you have a problem with the air mass sensor or something affecting it's performance. a healthy digital ams should be able to produce 8 to 8.5 khz peak. also an air leak can affect it's performance or a leaky egr valve. do you have a smoke machine to check these? does your scanner show the dpf differencial pressure this should be near zero on idle. also have you tried checking this fault with a different scanner? where are you situated?
Re: Vauxhall Zafira
Posted by Piotr Sokolowski on March 10, 2012, 5:12 pm, in reply to "Re: Vauxhall Zafira"
It could be DPF problem -ecu is trying to regenerate the filter- but this is only what I'm thinking after reading your post.If you will diagnose it with obstructed filter and you would like to remove it let me know I can help you with remapping ecu for dpf removal.
Posted by George Georgiou on March 11, 2012, 10:42 am, in reply to "Re: Vauxhall Zafira" George Georgiou
Thanks for the replies so far.
I get the car back on Monday and will try and hang on to it for some more extensive testing. I will carry out some more diagnostics including a full smoke test to check for leaks and a look at the electrical switching on the injectors, as well as MAF performance now I have some idea ,thanks to George, of the frequency response, as well as a ckeck on EGR behaviour.
I do have a DPF differential pressure reading but thought it was something like 1 Kpa so need to recheck the value as when I looked at it I assumed it was OK i.e. it was nearly zero. Learned a lot about the DPF sensor on a 2.0 HDI peugeot the other day so have a good idea what values to expect but they were in mBar and yes at idle we should expect 0 pressure differential if the filter is unblocked and the sensor OK.
If nothing comes up I may try and force a regen although the Launch does not have this option or get a Tech2 from somewhere, or take it for a drive if the smoke is manageable.
Let you know how I get on .
George
Re: Vauxhall Zafira
Posted by Piotr Sokolowski on March 11, 2012, 10:46 am, in reply to "Re: Vauxhall Zafira"
yes you are right 1Kpa is ok - I hope this value is on idle/
Posted by Alan Lange on March 12, 2012, 9:34 pm, in reply to "Re: Vauxhall Zafira" Alan Lange
Hello George, I always check the pressure sensor with the ignition on, engine not running. Readings should be the same. Alan.
Re: Vauxhall Zafira
Posted by Iain MacCormick on March 13, 2012, 8:26 pm, in reply to "Re: Vauxhall Zafira" Iain MacCormick
Hi George
If this is trying to do a regen then make sure you keep an eye on the oil level.When attempting a regen they can fill the sump up with diesel suprisingly quickly.
Iain
Fixed #
Posted by George Georgiou on March 17, 2012, 7:54 pm, in reply to "Re: Vauxhall Zafira" Message modified by board administrator March 20, 2012, 3:15 pm
Thanks for all the replies.
It seems the vehicle was starting a regen and not completing.
I took the car for a good drive to get the engine hot and as I would slow down for junctions it would smoke and then as I accelerated the smoke would disperse , I then brought it back to the garage and put it on the ramp to check the DPF . Pulled out the rear temp sensor and checked the pressure feed pipework, all OK. Then decided to clamp the differential presure pipe and ran the engine and noticed that the pressure was building up slowly but on the next test drive I noticed that over 3 or 4 miles of brisk driving the pressure kept climbing up past 11kpa so took it back to the ramp and removed the clamp and the pressure immediately fell back to 1kpa or so.
On this experiment I am not sure why the pressure was building up as having clamped the rubber section of the pipe back to the sensor , I would expect no change as there is no back pressure from the DPF to the sensor. The other end of the sensor is open to atmospheric pressure . So not quite sure where or how the pressure differential could be coming from.
Whilst on the ramp I noticed that the rear temp sensor suddenly started getting hot and realised it was regening on the ramp at idle . The DPF got to 450 degrees on the rear and something like 260 degrees on the front sensor , it took several minutes before the regen stopped and rear sensor settled back to about 180 degrees. During this regen no smoke came out of the vehicle. After switching off the engine the DPF saturation fell to 52% from 125%.
Took it for a test and all was good no more smoke , no more regens and also the coil light indicating a regen was out.
The next day the garage on my advice decided to remove the DPF and it was soaked in traffic film remover for about 6 hours and then washed out with a steam cleaner for quite a while. Putting it back the immediate run poured out loads of steamy/smoke (not diesel smoke) for about 10 minutes and on another brisk drive this too cleared up completely. The DPF saturation was down to 8% but even after a short drive it still crept up to 14%.
Many thanks to Tony Attwood who took the time and trouble to ring me on the Monday and help me out with his advice and experience. We both agreed it must have been failed regens causing the smoke and possibly and oversaturated DPF not getting to the correct temperature to complete the cleaning and burn off the excess diesel. Tony suggested that the DPF should achieve at least 550 degrees for the regen to work .
I only got to 450 degrees on the rear sensor and it managed to complete the regen and put out the light but I suspect my earlier 'brisk' drive probably did the trick.
Time will tell.
By the way the engine never seems to run more than 77-85 degrees temp and max temp achieved at 2500-3000 rpm for quite a while when stationary gets me to 98 degrees before the fan cuts in. I think this engine may be running a bit on the cold side and this may have some effect on how well the regen completes.
on March 10, 2012, 12:04 pm, in reply to "