2006 VW Jetta TDI. I changed my air filter the other day and found what appeared to be engine oil in the air filter. Also, when the throttle is pressed and let off, a strange sound like a vaccum leak makes itself known. Any thoughts on this???

 

Neglect the oil -this appears to be normal as long you don't have a puddle of oil inside the air box.This would indicate something going wrong like a blocked turbo oil drain pipe.
All VW's I had have this oil coming from the PCV return pipe. It is absolute normal.

The other thing sounds like a boost pipe leak to me. Check the hoses and the clamps. check also lose connectors like vaccum hoses.Sometimes you popp them off while maintenance.
I hope this helps.

 

It may, all of the forums I have checked all said the same thing. EGR system malfunction. I'm going to check into that.

 

You mean the strange sound?

 

Yeah, mainly the sound.

 

that 'strange sound' might just be the vnt blowing off. do you have an exhaust or intake on the car?