Using A4 Fuel Filter Set Up on a A3

Any drawback or unknown ramifications if I were to use both the filter and return check valve that goes on top of the filter along with the associated clip of an A4 on a A3? This project 96 Passat had a small inline filter installed and want to go back to something more original. The check valve itself was north of $50 for the A3 setup and filters for the A4 seem more reasonably priced. I wouldn't think it would pose a problem but wanted to verify prior to switching over.

I can't think of any reason why that wouldn't be ok.

As a side note some of us have gotten rid of the thermo T check valve and opted for the earlier Mk2 filter that just has the in / out and filter vent. The more connections at the filter the more likely you'll get air leaks.

Having said that when I exhaust my supply of older Mk2 filters I might go back to the Mk3 setup, but it'll be a while yet before that actually happens.

Steve

a filter is a filter, if you can make it work, its fine.
I prefer the Ditzel mod... or however its spelled. CRAZY cheep

Mongler98 said:

a filter is a filter, if you can make it work, its fine.
I prefer the Ditzel mod... or however its spelled. CRAZY cheep

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What is the "Ditzel mod"? (Searched, found mention but no description…)

thats because i cant spell or remember half of these crazy names any more
but a quick google search and this is what im talking about, around here it has a name of Dietzel mod or something.
http://www.peachparts.com/shopforum/diesel-discussion/325340-2-micron-fuel-filter-cat-2.html

Ah, found my bookmark
The Dietzl Mod

I remember that mod, always seemed like another solution in search of a problem. AKA spending more money than you need to and making it more complex than you need to.

Steve

but.. its not, its cheep AF, much cheaper than Nictane and filters are available at like Walmart! i dont know if it is or not but there crazy cheap and available everywhere. Not to mention that it fixes the one issue of air bubbles via that heater T.
its technically making it less complicated.

I use the early A2 diesel filters, that get rid of the thermo T. They’re not 2 micron, but I haven’t had a fuel contamination issue.

-Todd

Mongler98 said:

but.. its not, its cheep AF, much cheaper than Nictane and filters are available at like Walmart! i dont know if it is or not but there crazy cheap and available everywhere. Not to mention that it fixes the one issue of air bubbles via that heater T.
its technically making it less complicated.

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That's really warped logic if you're coming up with 'less complicated' for all that. If you want to do it and want to spend money you don't have to just say so, but don't try and twist it into something that it's not.

The least expensive option is the easiest, and if the thermo T is really a thorn in your side use the older (and very cheap) Mk2 filters with only the bleeder screw on them. These also have water drain on them too. Did I mention they're cheap?

How many of these filters does a person go through anyway?

ToddA1 said:

I use the early A2 diesel filters, that get rid of the thermo T. They’re not 2 micron, but I haven’t had a fuel contamination issue.

-Todd

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Same thing I'm using right now on the B3V Todd.

As for cheap, Rock Auto was selling the Bosch OE filter for Mk3 / B4 TDI about a year ago on clearance for around $9 each. I stocked up on them, think I bought the last four they had after pointing it out to others via PM.

I still have at least two Mk2 non-T filters to go through also, and those were acquired somewhere for very little.

I recognize these aren't 2 micron but I doubt that in the dead of a mid-west winter I'd be able to pull through a 2 micron filter anyway, at least not without causing the IP some distress.

Again, if you want to do it that's great, but it is indeed a solution in search of a problem.

Steve

Steve Addy said:

How many of these filters does a person go through anyway?
Steve

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at least 1 for every 2 oil filters, so usually one every year

Mongler98 said:

at least 1 for every 2 oil filters, so usually one every year

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Seems excessive, but that's your choice.

Steve

The VW-mandated 20k-mile interval seems far too often in my opinion. If anything the filters become more effective as they fill up with debris. There are numerous reports of people basically never changing them and the car continues to run fine.

My understanding is that diesel fuel is filtered pretty well before it goes into the car. I am running my filters for 40,000 miles and have had zero issues, and could probably go for even longer.

Yeah I understand that the filter is cheap enough that it doesn’t make a bunch of sense to extend the interval, but my feeling on that is that the fuel system should be opened to contaminants as seldom as possible. If anything, the irony is that changing the filter increases the risk of dirt getting into the fuel system.