Fuel Micron Filtration

N.Johnson

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Sep 23, 2007
Location
Vancouver
TDI
2003 Jetta Wagon
I have a question concerning fuel filtration. I/We (wife) just bought a 03 jetta wagon and my first concern is what is the micron filtration of the stock filter. I'm a little puzzled to not be able to find a water drain valve? Where the heck is it? I have a 03 dodge cummins modded out to 487hp dyno proven and the first mod I did was a FASS pump/filters to 3 microns. I realize that this 03 jetta is not a common rail which is sensitive to more than 5 mics filtration, according to Bosch. However, not to compare apples to oranges what is the forums educated consensus on the filtration micron specs. That said this motor will only see dino diesel and b5-20.
 

Joe_Meehan

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Sep 3, 2005
Location
Ohio USA
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NB TDI, 2002.5, Silver
I believe the standard filter is 3 mics, but I could be wrong. In any case the standard filter is quite sufficent.

You will no longer see the drain valve because the quality of avaialble fuel is much imporved over what was around when I got my first VW diesel. It is simply no longer needed.

Don't worry Be happy.
 

silverbox

Veteran Member
Joined
Jul 24, 2005
Location
Halifax Nova Scotia
TDI
jetta wagon 2003 silver
I don't believe the oem 03 fuel filter is anywhere near 3 microns, if i recall it's somthing like 15.
I put the Cat 2 micron on my 03 wagon.
 

TornadoRed

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silverbox said:
I don't believe the oem 03 fuel filter is anywhere near 3 microns, if i recall it's somthing like 15.
I believe you are right.

The redesigned fuel filter installed as OE in the Mk5's is supposed to be a major improvement. But I think the CAT filter still works better.
 

Joe_Meehan

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silverbox said:
I don't believe the oem 03 fuel filter is anywhere near 3 microns, if i recall it's somthing like 15.
I put the Cat 2 micron on my 03 wagon.

Could be, as I said I was not sure of the numbers.

In any case, has anyone ever seen an engine problem that was caused by the filtering ability of the OE filter?
 

mrGutWrench

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'03 Jetta Wagon, 5-speed, 563K Miles (July '23)
Joe_Meehan said:
(snip) In any case, has anyone ever seen an engine problem that was caused by the filtering ability of the OE filter?
__. What would be the engine problem caused by poor filtering ability of the OE filter? Let's see, would it be worn injection pumps and leaky, poorly operating injectors????? Yes, I think it would. A *number* of those have been reported.

__. Bosch says that the injector pump on an ALH (VW) engine has clearances of about 7 microns. Wonder what 15 micron particles would do in those clearances. If they're hard particles, it sounds like somebody is running their engine of lapping compound.

__. BTW, happy CAT filter kit user for 120K miles (my car and MzLauraLee's waggin). Total filter cost - $43 and $22 of that was for spares that we're still carrying for when the originals clog up. Just before we got our CAT filters, the stealer where MzLL bought her car told her that they wanted $56 for a stock filter (parts price only). Hmmmm, 5 times the cost for a filter that filters 5 times as bad .... gee, what a dilemma THAT it! :rolleyes:
 

Bob_Fout

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Indiana
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2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
mrGutWrench said:
__. What would be the engine problem caused by poor filtering ability of the OE filter? Let's see, would it be worn injection pumps and leaky, poorly operating injectors????? Yes, I think it would. A *number* of those have been reported.

__. Bosch says that the injector pump on an ALH (VW) engine has clearances of about 7 microns. Wonder what 15 micron particles would do in those clearances. If they're hard particles, it sounds like somebody is running their engine of lapping compound.

__. BTW, happy CAT filter kit user for 120K miles (my car and MzLauraLee's waggin). Total filter cost - $43 and $22 of that was for spares that we're still carrying for when the originals clog up. Just before we got our CAT filters, the stealer where MzLL bought her car told her that they wanted $56 for a stock filter (parts price only). Hmmmm, 5 times the cost for a filter that filters 5 times as bad .... gee, what a dilemma THAT it! :rolleyes:
Doggone those TDIs with over 200K miles and used only OEM filters and fluid at the proper intervals.
 

TornadoRed

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Even at only $25 per OE replacement filter, if I'd been using them and replacing at the 20k-mile recommended interval, I would have spent $250 on fuel filters in the last 200k miles. Instead I bought the kit from Greg Landuyt for around $105 and three replacements for $36, for a total of $151. So I got better filtration and saved $100.

Still on original fuel injection pump, too. There is no way of knowing whether it would still be working if I'd used inferior filters.
 

Georgeseq

Gone But Not Forgotten
Joined
Jan 2, 2002
Location
Columbus, Ohio
Yes, the OEM filter is extremely effective at filtering out bricks and birds from the fuel. As very well put in previous posts, the finer the filtration, the longer your fuel system components will last with certainty. It is as simple as that.. Which is why CAT puts its ultra fine filters on its engines..
As for the engines which fuel systems last 200,000+ miles, good for them... Lucky folks...
George Morrison, STLE CLS
 

Joe_Meehan

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NB TDI, 2002.5, Silver
mrGutWrench said:
__. What would be the engine problem caused by poor filtering ability of the OE filter? Let's see, would it be worn injection pumps and leaky, poorly operating injectors????? Yes, I think it would. A *number* of those have been reported.
The question still remains "Are those results due t poor filtering or maybe poor lubrication or defective parts to start with.

While in theory it is certainly possible to have damage, I seriously doubt if it occurs in real life.

It would appear that the engineers who design those cars don't believe it is a problem.
 

PDJetta

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Northern Virginia
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'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
The stock filter is in the 10 - 15 micron range, I think. A lot of us use a Catapillar 2 um filter here. This is especially critical in the A4 Pumpe Duses with the high injection pressures, which use the same 10 - 15 um filter the ALHs use. (the A5s got a better filter, that filters to about 5-7 um, I think). The cat could be beneficial for the ALH too, I think.

The "drain" is the drain tap on the bottom of the stock filter.

--Nate
 

dabear95

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Location
Roseville, MI
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2002 Golf GLS, Silver
Since I have modified my engine with additional fueling requirments I have stuck with the stock filter (plus I had a 120K miles suplly, lol). I have concerns about the flow of the Cat filter. Does anyone have any new data?

I just installed my last filter in stock...


Jason
 

bioduse

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in a galaxy far, far away
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pumpe duse
dabear95 said:
Since I have modified my engine with additional fueling requirments I have stuck with the stock filter (plus I had a 120K miles suplly, lol). I have concerns about the flow of the Cat filter. Does anyone have any new data?

I just installed my last filter in stock...


Jason
what sort of concerns?
 

TornadoRed

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dabear95 said:
Since I have modified my engine with additional fueling requirments I have stuck with the stock filter (plus I had a 120K miles suplly, lol). I have concerns about the flow of the Cat filter.
It flows well enough to serve as a secondary filter in Class 8 trucks. Unless your engine consumes several gallons per minute, I think 90-99% of the fuel passing through the filter will still end up being returned to the tank.
 

dabear95

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2002 Golf GLS, Silver
TR, the only problem I have with that argument is a Class 8 truck is not the same as a TDI. Does the truck have a fuel pump other then the injection pump? How much is the pump rated to pump? What are the demands of the engine, etc...


For example, if the TDI injection pump pulls at say 10 psi and the truck is 10 times higher then I could see why the filter flows more in a truck.

Finally, my thought is that even if I have a bit more crud, the pump "may" not be working as hard. All imaginary at this point, no proof, just talk. I see the arguments on both sides. Like I said, I just used my last filter so I am revisiting this now. :) (Hint - I want to justify the filter but not at the expense of pump life, it seems logical)


Jason
 

PDJetta

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'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
The Class 8 trucks use lift pumps. Remember, the CAT filter on these is a "polishing" filter. It gets the fine stuff the regular, big filter misses.

Now what I have wondered is, after many thousands of miles of use, if the CAT filter on the TDI "loads" with dirt and causes a higher pressure to build in the system.

I wonder because at 46,000 miles the electric lift pump failed in my PD (no warning, just quit while at 50 MPH, killing the engine) and the CAT filter had about 25,000 miles on it at the time. I replaced the filter after the dealer replaced the pump (under warranty). I wonder if a CAT filter restriction strained the fuel pump, causing it to fail, since the CAT is the only fuel filter the car has, in which case, could get plugged since its so fine.

--Nate
 

TornadoRed

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PDJetta said:
I wonder because at 46,000 miles the electric lift pump failed in my PD (no warning, just quit while at 50 MPH, killing the engine) and the CAT filter had about 25,000 miles on it at the time. I replaced the filter after the dealer replaced the pump (under warranty). I wonder if a CAT filter restriction strained the fuel pump, causing it to fail, since the CAT is the only fuel filter the car has, in which case, could get plugged since its so fine.
Those lift pumps have a terrible reputation, I'm surprised there hasn't been a complete recall on every TDI and non-TDI that uses that part number.

If CAT fuel filters were clogging or restricting fuel flow after less than 25k miles, then those of us running them for 50k-70k miles would have noticed something wrong. If you look at the Caterpillar website, and use the hour-of-operation figure for Class 8 trucks to estimate how long the CAT fuel filter should last in a TDI, the best guess is approximately 100k miles. I just keep getting impatient at 50k-70k miles and am unable to wait until 100k miles between fuel filter changes.

Highender: the CAT fuel filter is rated for two microns, not one. The replacements were $11+, now they are almost $14. If you are paying $16 for OE replacements, lots of club members probably want to know your vendor.
 

TornadoRed

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rjr311 said:
what would be the options for an 04 passat ?
tha cat web site says all but passats ...
The kit just slides into the original location in the A4 TDIs. You might be able to install it in a Passat TDI, even in the original location, but with some bracket and fuel line modifications.

Get together with someone in your area who has the CAT filter in their A4 TDI. Look under the hood of each and see if you can figure out how to mount a CAT filter in your Passat.

Edit: It looks like at least one person has made it work. Look here:
http://forums.tdiclub.com/showthread.php?t=97505
 
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highender

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Location
Northern California
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2012 Jetta TDI
TornadoRed said:
Highender: the CAT fuel filter is rated for two microns, not one. The replacements were $11+, now they are almost $14. If you are paying $16 for OE replacements, lots of club members probably want to know your vendor.

Hi TR :

Yes...sorry about typo...Cat filter is 2 microns.:eek:

I paid $54 including shipping, ( so it was $18 each, not $16. :eek: ) for the 3 Meyle fuel filters from Germany. I got them off Ebay. There is a person selling them in threes....


Nevertheless, the filtration of the CAT 2 um filter would be far superior to the regular filters, So I will use up the last two that I have, and then order a CAT filter kit from Lubrication Specialist....


Thanks...
 

DIESELprogrammer

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highender said:
I paid $54 including shipping, ( so it was $18 each, not $16. :eek: ) for the 3 Meyle fuel filters from Germany. I got them off Ebay. There is a person selling them in threes....
I seem to recall someone saying here that they could get WIX oil filters for $3 in a similar manor.

I guess I am just too concerned about “knock-offs” to go that route. However, I am comfortable with buying mail order from a reputable co – seen the WIX oil filter for $6. AND, I am most comfortable paying $10 at NAPA or $13 for a fuel filter at Western States CAT where I know whom I will talk to should I have any issues or concerns.

If I hadn’t purchased the Cat II for my first filter change 107k ago, I would probably have mail ordered the OEM filter. I like the parts manager at the local dealership – he is very knowledgeable, owns an early “bug,” and has been a leader on the local VW scene for lots of years. However, I just can’t swallow their prices, unless I have too!
 
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DIESELprogrammer

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TornadoRed said:
If CAT fuel filters were clogging or restricting fuel flow after less than 25k miles, then those of us running them for 50k-70k miles would have noticed something wrong. If you look at the Caterpillar website, and use the hour-of-operation figure for Class 8 trucks to estimate how long the CAT fuel filter should last in a TDI, the best guess is approximately 100k miles. I just keep getting impatient at 50k-70k miles and am unable to wait until 100k miles between fuel filter changes
Check out this thread from 3.5 years ago:

http://forums.tdiclub.com/showthread.php?t=73123&highlight=CAT+filter
 

retmil46

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Mooresville, NC, USA
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'05 Jeep Liberty CRD, 87 MB 300D Turbo
So happens I've worked at the Freightliner plant in Cleveland NC for the past 10 years. 1 1/2 years bolting together engines on the engine assembly line, and now as a QC inspector on the same line. I've seen plenty of CAT engines roll thru in my time.

There is no lift pump on these engines, only a single mechanical supply pump mounted on the front of the engine run off the accessory drive, and unit injectors run off the camshaft.

The fuel system is vacuum draw from the tanks until it reaches the supply pump. Plumbing is hard nylon tubing with ferrule type compression fittings.

In between the tanks and the supply pump is usually a large Davco prefilter/water separator mounted on the frame rail, the type with the large see-thru bowl mounted on top.

Downstream of the supply pump they have a Cat 1R0749 2 micron filter (a longer version of the 1R 0750 sold by Greg), prior to the fuel being sent to the injectors.

The flow path is - (Vacuum) Tank - Davco prefilter/water sep - supply pump - (Pressure) 2 micron filter - injectors - return to tank.

So in effect, yes, on the large Cat engines the 2 micron is being used as a polishing or secondary filter downstream of the pump where there is pressure to push the fuel thru and also minimize any entrained air coming out of solution.

If you do a little research on the Racor and Stanadyne webites, one of the problems they've encountered when using a 5 micron or finer filter on the vacuum side of a fuel system is that the filter acts like an air trap, the wetted media actually stripping the entrained air out of the fuel, the microscopic air bubbles being too large to easily pass thru. The air keeps accumulating until flow demand and differential pressure starts forcing the air thru, often causing problems up to and including engine stall.

The simple remedy they found was to locate the secondary/polishing filter downstream of the supply or lift pump. Just by maintaining some type of positive pressure on the fuel flowing thru the filter virtually eliminated any problems with entrained air coming out of solution.

Looking at pictures of used Cat filters that have been cut open, it's easy to tell which ones have been used on the vacuum and pressure sides of a fuel system - the ones that look as though only the bottom 1/3 of the element has been used were installed on the vacuum side, the ones that show even loading along the length of the filter element were used on the pressure side or downstream of a lift pump.

I use a Cat 2 micron filter on my '05 Liberty CRD as a secondary filter, along with a 4 psi centrifugal lift pump from Kennedy Diesel. I've experimented some with a used filter. Once the media in one of these Cat filters is wetted with fuel, you can't even force air thru it unless you can generate more d/p that you can muster with your own lungs and mouth - it takes some effort to push or pull fuel thru this fine a filter. And with the lift pump installed, the filter elements have shown even loading along the whole length.

As far as fuel quality having gotten to the point we don't need to worry about water separation any more, apparently no one has told the companies buying Class 8 trucks about this - every one has some type of water sep prefilter with drain on them.
 
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