Smoking and rough idle

[mm707]

2.0 tdi 170.
Hi, for years it's had a rough idle when cold, I can live with it. Any ideas why when stuck in traffic when engine cold it smokes like crazy ? smelly grey smoke.
Get going and runs great.
Not using any oil.
Thanks

 

[tobnh]

Could be DPF regen?

 

[SteveFIFE]

Agreed, it could be the dpf. Do you know how to do a forced regeneration, or better still do you have access to vcds which sets the timing off slightly and it makes the dpf go roasting hot after about 30 minutes and decreases the dpf load significantly. Failing that there might be an egr issue. I blocked mine off to stop the headache that is the egr. Hope this helps.

 

[mm707]

Thanks for the replies, could well be dpf, only done it occasionally. Will take egr off too and see what it's like.

 

[B7 bazz]

I had a very similar problem with my 170 rough idle smelly smoke but mine also had a lumpy spot between 1800 and 2000 revs with lots of going trough different things found out my timing was out and since having it done it has been spot on no rough idle no smoke and no lumpy spots I don't want to say yours is same problem as still could be something else but hope this helps you .

 

[Jamal Miah]

Hi all I have the same problem on cold starts it smokes like hell and rough idle, but drives fine no smoke while driving. I had drained the fuel filter into a cup and found that the diesel had soot particles in it. In going to clean the injector ports in the head and replace new O ring seals.

 

[Allyn78]

hi , i had the same problem on my car, lumpy idle on warm , excessive white smoke from exhausts. took my car to AVON TUNING in bristol and they fixed the problem for me. parently the cam timing was out on the inlet cam.

 

[Jamal Miah]

I'm due for a cam belt change so I'll check the cam timing. Thanks for the advice.

 

[Allyn78]

when you do the belt the pulleys are held in placeby pins
if remember what you need is vagcom and check the torson valve. you can adjust the cam timing by holding the cam pulley with the pin in it and move the cam itself. im sure i have read a thread on this site about it
hope that helps

 

[tobnh]

Agreed, it could be the dpf. Do you know how to do a forced regeneration, or better still do you have access to vcds which sets the timing off slightly and it makes the dpf go roasting hot after about 30 minutes and decreases the dpf load significantly. Failing that there might be an egr issue. I blocked mine off to stop the headache that is the egr. Hope this helps.

http://wiki.ross-tech.com/wiki/index.php/Diesel_Particle_Filter_Emergency_Regeneration

Coding II > 21295