SUNRG
Top Post Dawg
- Joined
- Oct 19, 2003
- Location
- Roanoke, VA
- TDI
- None currently. Previously owned 04 Golf TDI & 05 Passat GLS Wagon TDI
Rational
The OEM fuel filter has been virtually unchanged since the IDI VW diesels and when VW started making TDIs injection pressures increased and contaminant caused injector wear increased.
Enter the PD and injection pressures went thru the roof to 30,000+psi but *initially* the fuel filter was still unchanged. VW eventually realized what a problem pairing 30,000psi with an antiquated fuel filter was and completely redesigned the filter with a far more advanced filter media - beginning with the 2006 A5s.
The Mann MultimediaF filters in the A5s are outstanding, cutting edge diesel fuel filtration.
Unfortunately, that leaves us A4 and B5.5 PD owners to fend for our beloved TDI fuel pumping and injection systems!
If you stay with OEM fuel filtration your PD will run great for a long while, then pretty good, then OK and then not so well in comparison to when it was new but it's a gradual deterioration of performance so you may not notice it until it gets really bad. When it does get bad the cost of replacing PD injectors is quite high.
Upgrading to a modern high-performance diesel fuel filter should enable injection performance to be like-new for longer and performance deteriorization will be slower. The cost of upgrading is quite low and replacement FM100 filters are less expensive than OEM filters ...
Filtration Efficiency Data
Following is data straight from Mann and Stanadyne regarding the filtration efficiencies of the A4 OEM and FM100 filters using the same ISO/TR 13353 testing procedure.
ISO/TR 13353: gives a test procedure for evaluating the initial efficiency by particule counting of an internal combustion engine fuel filter by submitting the filter to a constant flowrate of test liquid.
A4 OEM/MANN: The filtration efficiency of WK 853/3 is 58% at 3-5 micron, according to ISO/TR 13353
Stanadyne FM100 5-micron: Average Particle Retention Efficiency (at 5-micron) Per ISO TR 13353, Sec. 6.2 - 97% @ 170 lph (45 gph)
Parts
FM100 Filter Head with 3/8” NPT Ports
FM100 6” 5um Fuel Filter Element
2 – 3/8 > 1/8 brass bushings
2 – 1/8 > 5/16 hose fittings
2 – 3/8 plugs
6’ – 7.5mm diesel fuel line
7 – stainless steel hose clamps
Tools
2 – line clamps
¼” drive
7/16 socket or combination wrench
11/16 socket or combination wrench
pliers
scissors
10mm socket
torx bit to remove fuel filter star bolt and replace with 5mm stainless steel allen bolt
Procedure
Pre - clean engine and "customize" FM100 head
1 - Prep and Install fittings on FM100 Filter Head
3 - Install Fuel Return Line
The OEM fuel filter has been virtually unchanged since the IDI VW diesels and when VW started making TDIs injection pressures increased and contaminant caused injector wear increased.
Enter the PD and injection pressures went thru the roof to 30,000+psi but *initially* the fuel filter was still unchanged. VW eventually realized what a problem pairing 30,000psi with an antiquated fuel filter was and completely redesigned the filter with a far more advanced filter media - beginning with the 2006 A5s.
The Mann MultimediaF filters in the A5s are outstanding, cutting edge diesel fuel filtration.
Unfortunately, that leaves us A4 and B5.5 PD owners to fend for our beloved TDI fuel pumping and injection systems!
If you stay with OEM fuel filtration your PD will run great for a long while, then pretty good, then OK and then not so well in comparison to when it was new but it's a gradual deterioration of performance so you may not notice it until it gets really bad. When it does get bad the cost of replacing PD injectors is quite high.
Upgrading to a modern high-performance diesel fuel filter should enable injection performance to be like-new for longer and performance deteriorization will be slower. The cost of upgrading is quite low and replacement FM100 filters are less expensive than OEM filters ...
Filtration Efficiency Data
Following is data straight from Mann and Stanadyne regarding the filtration efficiencies of the A4 OEM and FM100 filters using the same ISO/TR 13353 testing procedure.
ISO/TR 13353: gives a test procedure for evaluating the initial efficiency by particule counting of an internal combustion engine fuel filter by submitting the filter to a constant flowrate of test liquid.
A4 OEM/MANN: The filtration efficiency of WK 853/3 is 58% at 3-5 micron, according to ISO/TR 13353
Stanadyne FM100 5-micron: Average Particle Retention Efficiency (at 5-micron) Per ISO TR 13353, Sec. 6.2 - 97% @ 170 lph (45 gph)
Parts
FM100 Filter Head with 3/8” NPT Ports
FM100 6” 5um Fuel Filter Element
2 – 3/8 > 1/8 brass bushings
2 – 1/8 > 5/16 hose fittings
2 – 3/8 plugs
6’ – 7.5mm diesel fuel line
7 – stainless steel hose clamps
Tools
2 – line clamps
¼” drive
7/16 socket or combination wrench
11/16 socket or combination wrench
pliers
scissors
10mm socket
torx bit to remove fuel filter star bolt and replace with 5mm stainless steel allen bolt
Procedure
Pre - clean engine and "customize" FM100 head
- the day before doing any fuel system work i clean my engine to reduce the risk of dirt being introduced into the fuel system.
- cut the mounting bracket off the FM100 head as the filter will be held in the OEM filter bracket. i used a common 12" hacksaw with a 24tpi blade. i went slow, easy and carefully and it probably took me 25 minutes.
- carefully wrap all fitting threads in teflon tape being certain to only apply tape to the threads. Do not to allow any tape to obstruct the fuel flow path.
- tighten all fittings down onto FM100 head. when looking at the front of the FM100, install plugs to the right side, hose fittings to the left side.
- All fuel lines are completely removed *with the exception of the fuel line that delivers cleaned fuel from the fuel filter to the engine*. Use hose clamps to reduce fuel spillage. The return line that goes from the engine to through a fuel sensor to the thermostatic "T" is removed after the fuel sensor (ie - the fuel sensor remains in place).
- Loosen , remove and loosely replace the star bolt with a 5mm stainless steel allen bolt.
- Remove and discard the OEM fuel filter.
On my TDIs I remove the thermostatic "T" so this image shows the return line going from the engine to a fuel sensor and then directly back to the fuel tank (fuel actually travels through a fuel cooler after leaving the engine bay en route to returning to the fuel tank).
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