Where is the fuel filter on my 1999 Dodge Neon? My owner's manual does not even have a maintenance interval to change the fuel filter. How come they don't have a schedule to change it?
You are asking a question that auto technicians have been trying to explain to customers for a long time!
Chrysler/Dodge/Jeep have decided that fuel filters don't need to be changed as preventive maintenance! So they designed the fuel filter to be a part of the fuel pump assembly that can't be changed or serviced without removing the fuel tank.
The manufactures base their decision on the fuel filter because the fuel delivery systems on Dodge/Chrysler/Jeep vehicles are "RETURNLESS". This means the fuel pressure is constant and does not change depending on the vacuum of the engine. So there is no excess fuel to be returned to the fuel tank to be re-filtered.
On the "RETURNLESS FUEL SYSTEM" that the fuel is filtered only ONE TIME, before the engine uses it to run!
Previous Chrysler/Dodge/Jeep fuel delivery systems would filter the fuel several times (5 to 7 times on average) before it was needed to run the engine! This was because the fuel pressure regulator was controlled by engine vacuum. Every time the engine vacuum drops (when you push the gas pedal down) the fuel pressure increases. The vacuum controlled fuel pressure regulator cuts the 100 psi fuel pressure down to 32 to 38 psi .
So, the extra fuel that was not used by the engine to run will return to the fuel tank to be used and filtered again.
Does this mean the fuel filter can't or should not be changed as preventive maintenance? In my opinion changing the fuel filter every 60 thousand miles may allow your electric fuel pump to last twice as long.
With the average price of the modular fuel pump assembly costing several hundred dollars, the only way I know to determine if the fuel filter may be restricted is to perform a fuel pump low amp/wave pattern test.
This is the ONLY way you can determine how much "effort" is being demanded from the electric fuel pump to push the fuel to the engine.
Of course unless you have a lab scope you will need to see a professional repair shop to perform this test.
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