My buddy has a 2003 vw jetta and it's not getting good mileage at all. Like 20 mpg, no major parts have been replaced. What could cause this to happen? Any pointers would be great guys. thanks

 

Dirty air filter, dirty fuel filter, dirty EGR and intake.

Is the car a manual or auto?

 

Coolant temp sensor, MAF sensor, sticking wastegate actuator. Could be a number of things. Are there any codes, ckeng lights???

 

What these guys have listed is what I would have said. Ask your buddy if he drives like he stole it or just drives really old lady like? These cars need to be driven hard or they will act as you have indicated.

Just my 2 cents

 

he drive's it like an old lady and no thrown codes and it's an auto

 

well there is the issue he drives like an old lady. i bet the egr is clogged and the turbo is coated in soot. sounds like the car needs to be taken for a long trip and driven hard. diesels have to be driven like you just stole the thing and the cops are behind you. they like to work.

 

what he said.

 

The EGR will still soot up, regardless of how you drive it. You have two things working against you

1.) Diesel exhaust being recirculated back into the intake tract.
2.) A CCV system that will coat your intake with a fine oil mist. Soot + Oil mist = clogged intake and EGR eventually.

I'd say start with the air filter, fuel filter first as they are cheap. Also there is a "snow screen" that like to get clogged. Watch the video here

 

Is there any way to block the EGR? Anyone done it? Good, bad or otherwise?

 

There is a way to block it, but it will set a CEL. The best way to do it would be to block it before it enters the cooler AND disable it with a VAG-COM so it doesn't throw a CEL.