02 Jetta, 400 miles per tank?

Vandor

Member
Joined
Sep 17, 2014
Location
Maryland
TDI
2002 VW Jetta TDI GLS
Hello,

New here, I recently bought an 02 Jetta TDI GLS. It is in fairly good condition, only had 97K miles on it, but it is an automatic (the dreaded 01M Trans). As the title states, the vehicle is only getting 400 miles per tank (roughly 30mpg). Most of my daily commute is about 80% Hwy, 20% City.

I've had the car in the local VW Dealership to get it checked out. They replaced the accelerator assembly and the thermostat, those were codes it was sending out. Other than that they don't see anything wrong with it.

I've done some research and noticed that even with an automatic, this car should be reaching around 38-40 mpg. I would like to point out however, the car sometimes struggles to start, when it hits 40 MPH it bucks (Consistent, every time it hits 40mph) it's also kind of sluggish in accelerating.

Other than that, nothing really stands out, it doesn't soot, stall etc...just kind of wonder what should be my next approach to figuring out if the car has an underlying issue.

Thanks.
 

Westro

Veteran Member
Joined
Sep 12, 2002
Location
Minnesota
TDI
2002,2002,2003
Wife drove a 2002 ALH auto for 100K miles. It would average about 5.5 Miles per gallon below my manuals. So she was always around 42 MPG, my manuals pull 47 to 48 over 300+K.

EGR, intake cleaning and MAF is where I would start and then move into the tranny.
 

fruitcakesa

Top Post Dawg
Joined
Feb 18, 2007
Location
Vermont
TDI
04 jetta 5 spd wagon
Is the torque converter locking up? My 02 auto never broke 35 mpgs as a result of no TC lockup.
Also a plugged intake will cut power and mileage.
 

Vandor

Member
Joined
Sep 17, 2014
Location
Maryland
TDI
2002 VW Jetta TDI GLS
Hwy speed is usually about 70-75.

I have an extended 2 year warranty on the engine and trans when I bought it. So if the tranny is going out it is covered.

I'm not sure about the torque converter, wouldn't know what to look for if that were bad.
 

Jesus Is Lord

Veteran Member
Joined
Jan 24, 2014
Location
Hersey, MI
TDI
2005 Passat TDI Wagon 144,000 2003 Eurovan VR6 2007 Touareg V10 TDI 158,000
Fuel filter may be plugged
Brake may be dragging
Snow screen may be plugged
Intake may be plugged
MAF sensor may be bad
Timing on injection pump may be off
IQ may be off
Air filter may be restricting flow
The trans may be acting up (check for codes)
 

Vandor

Member
Joined
Sep 17, 2014
Location
Maryland
TDI
2002 VW Jetta TDI GLS
Is there a different port for the TCM?

I went to start the car and it gave me a DTC:01 17978 01/01 code, which is an Immobilizer issue?

Other than that, the 4 options the VAG-com has Engine/A-T/SRS/ABS, none pull codes.
 

Jesus Is Lord

Veteran Member
Joined
Jan 24, 2014
Location
Hersey, MI
TDI
2005 Passat TDI Wagon 144,000 2003 Eurovan VR6 2007 Touareg V10 TDI 158,000
Ok
You probably don't have any codes.
I would check the other things mentioned.
 

Jesus Is Lord

Veteran Member
Joined
Jan 24, 2014
Location
Hersey, MI
TDI
2005 Passat TDI Wagon 144,000 2003 Eurovan VR6 2007 Touareg V10 TDI 158,000
I personally had a dragging rear brake, plugged snow screen, bad maf sensor, and timing off. I was getting roughly 32 mpg before I fixed those things. Once I had them fixed I was getting roughly 38-44 mpg.
 

Vandor

Member
Joined
Sep 17, 2014
Location
Maryland
TDI
2002 VW Jetta TDI GLS
I checked the MAF, Air Filter and snow screen, neither looked bad. Snow screen was clean and clear. MAF looked like it was recently replaced, car shut off when I disconnected it. Air filter didn't look bad.

I'm not car savy by any means, so I'd have to get a mechanic to look at the rest.
 

1854sailor

Resident Curmudgeon
Joined
Aug 10, 2004
Location
Westerly, RI
TDI
2015 Golf SE SportWagen, 2015 Golf SE Hatch Back.
Where in MD are you? As Bob indicated, there are several excellent TDI mechanics nearby.
 

Jesus Is Lord

Veteran Member
Joined
Jan 24, 2014
Location
Hersey, MI
TDI
2005 Passat TDI Wagon 144,000 2003 Eurovan VR6 2007 Touareg V10 TDI 158,000
The car should not shut off when you disconnect the MAF sensor. Are you sure you did the right one.
 

ndm101

Member
Joined
Jul 26, 2014
Location
Germany
TDI
2002 Jetta
I too have a 02 Jetta TDI automatic and consistently get roughly 400 miles per tank. However, I am in Germany and I drive 60-100 mph (100 - 160 km/h) almost everywhere I go. Is this mileage good for speeds this high.
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
I too have a 02 Jetta TDI automatic and consistently get roughly 400 miles per tank. However, I am in Germany and I drive 60-100 mph (100 - 160 km/h) almost everywhere I go. Is this mileage good for speeds this high.
400 miles for how many gallons / liters of fuel?
 
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