Hello,

I have a 2002 Jetta wagon 1.8T automatic transmissionand I noticed that my MPG dropped significantly in the last few weeks. I used to get approx 28 mpg combined and now I get 20 mpg. This summer I replaced my airfilter, sparkplugs, timingbelt and waterpump and last week I started using full sythetic oil, the car has 106.000 miles.
Does anyone know what might be wrong?

Thanks
PS I love the Jetta wagon, people see the wagon and think ohh i will race this one at the light too bad......

Pieter

 

i could be the timing belt, if the person that replaced the belt moved the teeth on the gear one or two degrees, it could have affected your timing which could have affected your power output, and your fuel efficiency

 

Check your exhaust- if it smells funny or is coming out black it's probably the O2 sensor.

 

Thanks I will check that!

 

oh maybe it could be whats called a lead foot if you get rid of that it might help lol im jk, it could also be a clogged fuel system so either buy good quality fuel or i have heard that techron works really well try it

 

when was the last time the fuel filter was replaced? If anything put some injector cleaner in it and see what happens.

 

i would have to agree with you. i had the same problem and after my timing belt went out and i when it go fixed it did the same and my mpg when down about the same as you and after i got it fixed it was all good.

 

as swedishgp keeps saying, check the cat ..... i just replaced mine and my MPG jumped up 6-7 mpg and is steady at that number

 

yeah ... not to mention my famous VR6 coil pack is cracked .... so its tempermental ... gotta fix it soon ....

 

thats ashame, you think volkswagen had enough time to see they were ****, and redesign or something .... its one of only a few downfalls for VW