poor mpg 2004 525i
07-01-2012, 09:52 PM
#11
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My Ride: 535i
Model Year: 2008
i appeciate all the help , changed the spark plugs = got 2-3 miles improvement , tire pressure - never checked unless computer messaged me , have to check air filter and work on the maf , btw rotors are bit rusty on the inside (car is bit shaky when braking at higher speeds).will keep you guys updated
thanks again
thanks again
07-02-2012, 05:27 AM
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My Ride: 525i
07-02-2012, 06:06 AM
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My Ride: 545i 2004, SMG, Sport, Nav, Logic-7, Bluetooth phone retrofit
The flat tire warning doesn't go off when all the tires gradually lose air over time (on the 2004 - no pressure sensors on the wheels). You have to check it manually. The FTM works by observing changes in differential rotation rates.
The 2004 has the M54 engine, I believe. At that age and mileage you probably need new VANOS seals. That causes bad MPG, and it's a well-known problem on the M54. Get a set of seals from Beisan Systems - better than OE.
The 2004 has the M54 engine, I believe. At that age and mileage you probably need new VANOS seals. That causes bad MPG, and it's a well-known problem on the M54. Get a set of seals from Beisan Systems - better than OE.
07-04-2012, 01:07 PM
#14
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i have only 80k , mpg dropped significantly , normaly i was making about 400-440 on tank , after 4 month in the garage .... 350 
, changed spark plugs today , ...any other suggestions...?
tire pressure ok , have a minor leak on engine(mechanic quoted $300 labor and part(only $20), told me it is normal for all bmw since the gasket is getting dried after awile)... oil level ok all the time ....computer shows 18-19mpg , dont floor at all
, changed spark plugs today , ...any other suggestions...?tire pressure ok , have a minor leak on engine(mechanic quoted $300 labor and part(only $20), told me it is normal for all bmw since the gasket is getting dried after awile)... oil level ok all the time ....computer shows 18-19mpg , dont floor at all
Could be a valve cover gasket leak. If you're so inclined rip the car apart and clean it.
The flat tire warning doesn't go off when all the tires gradually lose air over time (on the 2004 - no pressure sensors on the wheels). You have to check it manually. The FTM works by observing changes in differential rotation rates.
The 2004 has the M54 engine, I believe. At that age and mileage you probably need new VANOS seals. That causes bad MPG, and it's a well-known problem on the M54. Get a set of seals from Beisan Systems - better than OE.
The 2004 has the M54 engine, I believe. At that age and mileage you probably need new VANOS seals. That causes bad MPG, and it's a well-known problem on the M54. Get a set of seals from Beisan Systems - better than OE.
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