In march i bought a used 2006 jetta tdi with 136k (5 speed)to replace my 2013 tdi jetta that i sold back to vw. After the first full tank of gas, the gas light turned on around 440 miles. Fast forwards to august and it went down to around 380 miles before the gas light turned on. I replaced the fuel filter two weeks ago and now the gas light turned on around 424 miles. Both my 2012 and 2013 would get around 490-500 miles doing city alone. Ive read about the thermostat not allowing the car to war up but i checked my temp with a e327 obd 2 reader and it read 188.6. What else should i check to get better mpg?
bad fuel economy 2006 jetta tdi
- Thread starter yoda254
- Start date
1st, what kind of driving are you doing? what mix of city / highway?
Do you have the amount of fuel you filled to get the tank full again, that we we can figure the true MPG, rather than guessing it by when the fuel light came on. Your newer Jetta had a different size tank, and a completely different engine, so not really a fair comparison there.
If the Fuel Econ is determined to be on the low side for the driving you are doing, the next step I would do would be to scan the car and see what your "Torsion" (cam crank relationship) value is, and see if there is any adjustment to be had there.
After that, standard stuff - more scans to see injector balance #'s mass airflow readings, boost requested vs actual, (you already mentioned) operating temperature etc.
Failing all that, I would also look at compression.
When was the timing belt last done, and what parts were replaced?
Do you have the amount of fuel you filled to get the tank full again, that we we can figure the true MPG, rather than guessing it by when the fuel light came on. Your newer Jetta had a different size tank, and a completely different engine, so not really a fair comparison there.
If the Fuel Econ is determined to be on the low side for the driving you are doing, the next step I would do would be to scan the car and see what your "Torsion" (cam crank relationship) value is, and see if there is any adjustment to be had there.
After that, standard stuff - more scans to see injector balance #'s mass airflow readings, boost requested vs actual, (you already mentioned) operating temperature etc.
Failing all that, I would also look at compression.
When was the timing belt last done, and what parts were replaced?
I do mostly mixed driving 60 city /40 hw. I usually fill around 14.gallons I've seen 14.5 once since ive owned it.I thought the tank size was 14.5 gallons (the same size as my 13).I ve look on fuelly and seen other with way better fuel range then me even with city driving. The longest trip I've taken was when i bought the car in Houston and drove it back to Austin. I'm guessing i will need a vagcom to check everything? I forgot to mention that i did the whole diesel purge to help clean my injectors before replacing my fuel filter.
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When was the timing belt last done and which parts were replaced?
It will help to know exactly how many miles vs how many Gallons. Did you keep any of the receipts?
Yes, VCDS / VagCom would be the first place I would start.
It will help to know exactly how many miles vs how many Gallons. Did you keep any of the receipts?
Yes, VCDS / VagCom would be the first place I would start.
crazyrunner33
Veteran Member
Other basics that are overlooked include tire pressure, checking to see if the brakes are dragging, restriction in the intake(air filter, anti-shutter valve partially closed, dirty intake manifold). Once you get VCDS, check the fuel temperature sensor, coolant temperature sensor, MAF, and torsion values.
Have you also performed a camshaft and lifter inspection lately?
Have you also performed a camshaft and lifter inspection lately?