Loss of mpg

elchimpo

Member
Joined
Sep 29, 2016
Location
90723
TDI
2006 jetta
2006 Jetta tdi
145,000 miles

I was averaging 300 miles to half a tank. It dropped to 250 miles half a tank. Now its about 200.

I've changed air filter, oil, oil filter, new tires, wheel alignment, front and rear brake pads and disk brakes, and fuel filter.

When I changed fuel filter I notice some metal pieces in the old fuel filter. I'm not sure if my fuel pump is going out.
 

dandywriter

Veteran Member
Joined
Jul 18, 2007
Location
Ottawa (Kanata), Canada, eh?
TDI
2014 Golf Wagon 6M
1. Metal pieces in fuel filter does not sound good.
2. When you replace tires, your mileage will suffer for a while (heavier than old ones, possibly higher rolling resistance).
3. Check that emergency brake is not dragging.
4. Do you run a/c? If the mileage decrease matches increased a/c use, it would explain some of it.
5. Have you changed your cam? When was your last timing belt change? What oil do you use? Type of transmission?
 

relumalutan

Veteran Member
Joined
Dec 6, 2012
Location
Michigan
TDI
06 Jetta TDI Special Edition
Metal pieces in the filter of an 06 probably means the camshaft and the lifters are shot.
 

tdiatlast

Top Post Dawg
Joined
Jan 21, 2009
Location
Fort Worth, Texas
TDI
2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
relamalutan: he found metal in the FUEL filter, not oil filter.;)
 
Last edited:

elchimpo

Member
Joined
Sep 29, 2016
Location
90723
TDI
2006 jetta
1. Metal pieces in fuel filter does not sound good.
2. When you replace tires, your mileage will suffer for a while (heavier than old ones, possibly higher rolling resistance).
3. Check that emergency brake is not dragging.
4. Do you run a/c? If the mileage decrease matches increased a/c use, it would explain some of it.
5. Have you changed your cam? When was your last timing belt change? What oil do you use? Type of transmission?
I haven't changed my cam. The previous owner changed it.
 

dabeetereater

Well-known member
Joined
Apr 2, 2012
Location
ocala fl
TDI
96 tdi passat
if u have metal in fuel filter you high pressure fuel pump is probably going bad as the return line goes back into the filter from the hpfp that is the only way metal is going to get into the filter
 

tdiatlast

Top Post Dawg
Joined
Jan 21, 2009
Location
Fort Worth, Texas
TDI
2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
if u have metal in fuel filter you high pressure fuel pump is probably going bad as the return line goes back into the filter from the hpfp that is the only way metal is going to get into the filter
sorry...OP's car is a 2006, which does NOT have HPFP.;)
 
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