2010 VW Jetta TDI Cold Start Idle Issue

[plrprecision]

Greetings!

I have a 2010 Jetta TDI with 48K on the odometer. About a month ago, when I would cold start in the AM it would idle rough, then smooth out once I begin driving. I read on another forum that the intercooler pipes and core on this model are known to retain moisture which mixes with oil and creates a 'mukky' mess. I have cleaned the pipes three times now and get out about a handfulls worth of oily goo with beads of moisture throughout. Any ideas what could cause this issue?

Thank you in advance!

 

[oggb]

Blowby from the PCV system is my best guess. A handful is quite a lot of blowby, however. It wouldn't take much oil to be then emulsified with water to make it look a lot worse than it is, I suppose.

 

[JHZR2]

What oil are you running?

Also, do you know that your glow plugs are up to snuff? At 48k, ZGPs with afterglow and long shafts may well be getting weak and contributing to rough operation, even if not throwing a signal that they are getting bad.

Id put a multimeter on the GPs and see if their resistance is consistent. Maybe both cold and hot.

Ive seen plenty of diesels run just fine with globs of gunk in their intakes. EGR on diesels is nothing new, so soot and gunk buildup in the pipes isnt either, though some would like to make it sound like it is a new thing...

 

[plrprecision]

I ran LubroMoly Top Tec 4200 for the first 30K. Since then I have been running Pentosin SuperPerformance III / 507 spec oil. I changed my air filter at 18K and 40K. I will look to test the glow plugs, thank you for that advice.

 

[mechtech2]

Sounds lean at start up.
Could be a temp sensor that tells the computer the engine is cold.
Vacuum/intake leaks are always possible, and would also cause this symptom.
Check with some VW forums for common problems, though.