Constant grey smoke from exhaust while driving 4.2 d4d

[JayT]

Hi all, looking for some advice regarding my 05 mk2 d4d 2.0.

This car seems to have numerous issues with it at the minute and I am struggling to work out which avenue I should be going down without replacing part after part hoping that one fixes it.

First main concern is that I get constant grey smoke from the car while engine is running, this increases with acceleration and happens when the car is idling too.

Its not a sweet smell so guesses not coolant, more of just a dirty diesely smell that would make you cough.

I was thinking maybe bad injectors? Though engine runs fine, revs well, doesn't miss fire and starts on the button, mpg seems to be well down though. Was also thinking maybe valve seals? Need to check oil again to see if it burning any though.

Also EML light keeps coming on with code p400, egr flow. It's had a new egr unit and I've had it off and cleaned it which all seems okay, it is a bit sticky right at the top when you try push it down but being a new unit I figured this would be normal.

Its also had a new turbo core and injector seals so would rule those out. 

Anything you can think to get rid of the poor mpg and grey smoke would be appreciated.

Regards 

Jason

 

 

 

 

 

 

[igormus]

On 2/16/2022 at 10:34 PM, JayT said:

Hi all, looking for some advice regarding my 05 mk2 d4d 2.0.

This car seems to have numerous issues with it at the minute and I am struggling to work out which avenue I should be going down without replacing part after part hoping that one fixes it.

First main concern is that I get constant grey smoke from the car while engine is running, this increases with acceleration and happens when the car is idling too.

Its not a sweet smell so guesses not coolant, more of just a dirty diesely smell that would make you cough.

I was thinking maybe bad injectors? Though engine runs fine, revs well, doesn't miss fire and starts on the button, mpg seems to be well down though. Was also thinking maybe valve seals? Need to check oil again to see if it burning any though.

Also EML light keeps coming on with code p400, egr flow. It's had a new egr unit and I've had it off and cleaned it which all seems okay, it is a bit sticky right at the top when you try push it down but being a new unit I figured this would be normal.

Its also had a new turbo core and injector seals so would rule those out. 

Anything you can think to get rid of the poor mpg and grey smoke would be appreciated.

Regards 

Jason

 

hi Jason

the main possible reasons are:

- injectors are worn down;

- engine \ turbo suction filter is clogged;

- variable vanes (turbo) are not smoothly rotated relating to current engine load (+ impulse tube with vacuum actuator);

- late injection timing;

- possible airr suction thru primer buster pump \ fuel filter;

- possible electrical errors belong to injection circuit;

- EGR clogging;

 

Grey colour is overfueling during combustion stroke.

Blue colour - oil burning issue (valve seals \ piston rings)

All above is from my personal experience

Cheers \ Igor

 

On 2/16/2022 at 10:34 PM, JayT said:

 

 

 

 

 

 

[JayT]

Hi Igor,

Thanks for your reply.

To follow up on your points...

- injectors are worn down; - I have suspicions that this could be the reason (car at 155k and no history of injectors being replaced) these are quite a costly part though so am I best getting the injectors tested first or is this possible to DIY with one of the injector test kits?

- engine \ turbo suction filter is clogged; - Air filter is fairly new having only covered some couple thousand miles.

- variable vanes (turbo) are not smoothly rotated relating to current engine load (+ impulse tube with vacuum actuator); - I have replaced the turbo core and checked that vanes are moving freely, have also checked actuator with a hand vacuum to recommended specs according to the 1CD-FTV engineers manual. 

- late injection timing; How would I go about checking this??

- possible air suction thru primer buster pump \ fuel filter; - by this do you mean there could be an air pocket in the fuel system or leak into where the fuel filter is? I did replace fuel filter recently so will have to check the seals on it, where is the primer pump located?

- possible electrical errors belong to injection circuit; Again what electrical errors should I be looking for? broken relays/sensors etc.. or actual electronic components?

- EGR clogging; - I have had egr off which is clean and moves freely.

 

I have also ordered VCI cable with techstream to hopefully help diagnose any possible issues, I will report back any findings.

Thanks again

 

Jason