Water fuel separator

sledstorm1

Veteran Member
Joined
May 16, 2009
Location
Austin MN
TDI
2011 Golf Tdi 4dr 6mt
From my understanding our cars no longer have a water in fuel light. Is there an after market kit to add a water fuel separator before the fuel filter?

Sent from my Ally using Tapatalk
 

yatzee

Top Post Dawg
Joined
Jan 4, 2004
Location
Montreal, Qc
TDI
see sig
not that is available yet. I would like to install a Cat Filter kit on my folks MK6... I have my eyes open.

Why would you want to install a separator? VW hasn't used 1 of those in years.
 

Joe_Meehan

Top Post Dawg
Joined
Sep 3, 2005
Location
Ohio USA
TDI
NB TDI, 2002.5, Silver
Have you had problems with water? when I got my first diesel back in the 1970's water in fuel was a not unusual problem. Today it is rare. However if you live in some areas where supplies are not all that good, it could be a problem.

If you have not had a problem and are just reacting to what grandpa had to deal with, you really don't need to worry. Most supplies are fine.

Good Luck
 

sledstorm1

Veteran Member
Joined
May 16, 2009
Location
Austin MN
TDI
2011 Golf Tdi 4dr 6mt
I have not had any trouble yet, but my 07 duramax has a sensor in the bottom of the fuel filter, and sense I can't add a light to my car I thought the next best thing would be to add a water fuel separator and check it twice a month.

Sent from my Ally using Tapatalk
 

n1das

TDIClub Enthusiast, Veteran Member
Joined
Jun 11, 2002
Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
From my understanding our cars no longer have a water in fuel light. Is there an after market kit to add a water fuel separator before the fuel filter?

Sent from my Ally using Tapatalk
TDIs have never had a Water In Fuel light in the USA, at least in generations Mk4 and later. Not sure about Mk3 and earlier in USA and all generations outside the USA.

I wish our TDIs had a Water In Fuel (WIF) sensor in the fuel filter and a Water in Fuel light on the dash. Adding an aftermarket water separator is a good idea and something I've thought about doing but haven't bothered and haven't found a good one to use. I think an Mk6 and later dashboard has an unused Water In Fuel light that maybe could be used.

As others have said, watery fuel is rare these days compared to years ago. Also stick to fueling up only at busy high volume / high turnover stations along major routes to avoid getting watery fuel. This is most important during the winter months. And regularly use an additive that takes care of water and add lubricity as cheap insurance. Although watery fuel is less of a problem today compared to years ago, it is still something to be avoided at all costs. :eek:

Good luck and Welcome to TDIclub. :cool:
 
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specsalot

Veteran Member
Joined
Jul 30, 2011
Location
Florida
TDI
Currently none
Stanadyne has a nice line of modular filtration equipment that can do many of the things we would all like (water in fuel warning, separation, pre and or final filtration, even heating).

http://www.stanadyne.com/view.php?id=26

PLEASE BE FOREWARNED that any changes to the fuel transfer system which impact the supply (pressure / volume) to the HPFP or restrict return flow to the fuel tank could have detrimental impacts to your HPFP.

According to the narrative, if HPFP supply pressure falls below ~ 63 PSIG the overflow valve will close which will reduce the recirculation of fuel throught the pump. This recirculation flow helps cool the HPFP. If the return side after the HPFP experiences a big change in restriction, it will push up HPFP supply pressure. This may impact the ability of the system to regulate CR pressure. Neither of these situations is good for your HPFP.

I'm not posting this to be a smart axx. Threads about filtration carry risks not necessarily well understood. Our fuel systems are engineered on an 'end to end' basis. Changes to existing filtration need to be vetted for their impacts to our fuel systems. Fuel system pressure is a function of lift and booster pump capacities, the relief valve on the lift pump, engine demand, pressure drop across existing filters, and a restriction orifice located at the return to the fuel tank.

BE CAREFUL if you are thinking about altering the existing filtration scheme for your TDI.
 
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whiplash willy

Veteran Member
Joined
Aug 1, 2011
Location
Portland Oregon
TDI
2012 4-Door Golf TDI 6MT w/NAV & Sunroof
not that is available yet. I would like to install a Cat Filter kit on my folks MK6... I have my eyes open.

Why would you want to install a separator? VW hasn't used 1 of those in years.
Do you think VW hasn't used a water separator in years, because it isn't necessary, or because it is cheaper for them to not put one in there? Maybe it is less likely today to have water in the fuel, but it is still possible. Why do more expensive diesel vehicles ($40k+ Diesel Trucks) have them if they aren't a good thing to have?

I think VW doesn't use them any more because in the long run, it is cheaper to not put one in every car, and just have to replace a few fuel systems along the way.

If I still own my car out of warranty, I will be adding in some after market "Safety Features" like a water separator, better filtration (So an exploding HPFP doesn't take out everything). Assuming these safety features are available.
 

yatzee

Top Post Dawg
Joined
Jan 4, 2004
Location
Montreal, Qc
TDI
see sig
And you will be wasting your money. The reason trucks have them is due to the very long fuel filter change interval as opposed to the cars.

The HPFP issue has been overblown. Try to not to fall into the paranoia.

Do you think VW hasn't used a water separator in years, because it isn't necessary, or because it is cheaper for them to not put one in there? Maybe it is less likely today to have water in the fuel, but it is still possible. Why do more expensive diesel vehicles ($40k+ Diesel Trucks) have them if they aren't a good thing to have?

I think VW doesn't use them any more because in the long run, it is cheaper to not put one in every car, and just have to replace a few fuel systems along the way.

If I still own my car out of warranty, I will be adding in some after market "Safety Features" like a water separator, better filtration (So an exploding HPFP doesn't take out everything). Assuming these safety features are available.
 

specsalot

Veteran Member
Joined
Jul 30, 2011
Location
Florida
TDI
Currently none
The HPFP issue is a bit overblown. I'm sure I'll forget all about it once there are lots of posters here with 150k miles on their HPFP's.

I don't think it's possible to protect the balance of a TDI fuel system from an imploding HPFP through the use of supplemental filtration.
 
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yatzee

Top Post Dawg
Joined
Jan 4, 2004
Location
Montreal, Qc
TDI
see sig
... and follow the fuel filter replacement interval, prime the filter before starting the car, don't use crappy no-name fuel, and, above all else, don't put ANY gas in.
 

specsalot

Veteran Member
Joined
Jul 30, 2011
Location
Florida
TDI
Currently none
The MB 3.0L CRD in my Jeep requires checking the fuel filter / water separator for water at 6k miles and replacement at 12k miles. (every other oil change). As far as I'm concerned VW is a bit suspect in their filter / interval. I raised this question with the VW dealer service department manager (pre-purchase) and they just quoted the company line on maintenance.
 

frugality

Top Post Dawg
Joined
Sep 19, 2003
Location
Spring Lake, Michigan
TDI
none, 2016 GTI
Do you think VW hasn't used a water separator in years, because it isn't necessary, or because it is cheaper for them to not put one in there? Maybe it is less likely today to have water in the fuel, but it is still possible. Why do more expensive diesel vehicles ($40k+ Diesel Trucks) have them if they aren't a good thing to have?
I had a Mk4 TDI for 284k miles, and did every fuel filter change myself. Those fuel filters had a water separator built into the filter -- a valve at the bottom that would allow you to drain the water out.

I never found ANY water.

So enjoy the fact that you don't need to worry about a water separator on these vehicles.

Adding water to your battery is a thing of the past. Running with your headlights on so that you don't 'overfill' your battery with electricity is a thing of hte past (though we now have DRLs for a different reason.) Cranking your windows up and down is a thing of the past. Pulling the choke knob before starting the car is a thing of the past. Viva la technologie! :)
 

dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
And you will be wasting your money. The reason trucks have them is due to the very long fuel filter change interval as opposed to the cars.
Yea, water separators are a waste. Guess thats why they put them on virtually all heavy equipment,tractors and trucks. The MB V6 bluertec diesel has a water separator built into the fuel filter plus a water in fuel sensor. Pure and total waste to design this into a fuel system.
But you're probably right about the VW fuel system. You would be wasting your money trying to protect a $10,000 dollar fuel system.
IF you have not picked up on it yet. I'm being totally sarcastic!
Every fuel system needs all the protecton available. My diesel lawn tractor has a water separator and although I've never emptied any water from it. I'm still glad its there.

I've never been in a situation where my seatbelt was needed,but I'm still glad its there. A water separator can protect your fuel system from that one time dose of water that can ruin your entire fuel system. It only takes once. Same with a seatbelt, it only takes once of not wearing it and it can cost you your life.

Well thats my public service announcement for the day. Rant over! Good night.
 
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40X40

Experienced
Joined
Feb 12, 2006
Location
Kansas City area, MO
TDI
2013 Passat SEL Premium
Yea, water separators are a waste. Guess thats why they put them on virtually all heavy equipment,tractors and trucks. The MB V6 bluertec diesel has a water separator built into the fuel filter plus a water in fuel sensor. Pure and total waste to design this into a fuel system.
But you're probably right about the VW fuel system. You would be wasting your money trying to protect a $10,000 dollar fuel system.
IF you have not picked up on it yet. I'm being totally sarcastic!
Every fuel system needs all the protecton available. My diesel lawn tractor has a water separator and although I've never emptied any water from it. I'm still glad its there.

I've never been in a situation where my seatbelt was needed,but I'm still glad its there. A water separator can protect your fuel system from that one time dose of water that can ruin your entire fuel system. It only takes once. Same with a seatbelt, it only takes once of not wearing it and it can cost you your life.

Well thats my public service announcement for the day. Rant over! Good night.
News flash!

The VW TDI is neither heavy equipment, a tractor, or a truck.

What we learned there is not always applicable here.

That is all.

Bill
 

dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
News flash!
The VW TDI is neither heavy equipment, a tractor, or a truck.
What we learned there is not always applicable here.
That is all.
Bill
Thanks for the news flash. I guess the laws of physics that apply to the diesels I listed,don't apply to the VW CR. Thats news to me. THANKS for setting me straight.
 
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ranger1

Veteran Member
Joined
Feb 6, 2005
Location
SouthEast
TDI
NA
News flash!

The VW TDI is neither heavy equipment, a tractor, or a truck.

What we learned there is not always applicable here.

That is all.

Bill
Neither is the MB E320 CDI sedan and yet it uses a fuel filter with water separator (pn 646-092-07-01).] This filter has a wif sensor calibrated to alert at 50% of filter canister capacity, a water chamber on the bottom and a separate(from the fuel filter) membrane exclusively for water separation.

For a sedan size car, MB went to some length to not only separate water, but also alert to the presence of water in the fuel.

You can see it in this link on page 37-38:
http://www.mercedestechstore.com/pdfs/331_0405update/03-331 pp diesel print(FAH) 5-5-04.pdf

Does the VW 3.0L V6 diesel engine use a water separator in its fuel filter system, or have a WIF icon on the instrument panel?
 

40X40

Experienced
Joined
Feb 12, 2006
Location
Kansas City area, MO
TDI
2013 Passat SEL Premium
The VW TDI is not a MB E320 CDI either.

Look guys, you just cannot compare one car design to another unless you have a full and complete understanding of the relevant parts of both designs.

Having a FULL understanding of said designs is impossible without having access to ALL of the engineering data on said designs from both manufacturers.
(at least the relevant portions)

Now lets bring this thread up from the grade school level and stop comparing apples to oranges and then complaining that they are not alike.:)


Bill
 
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dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
The VW TDI is not a MB E320 CDI either.

Look guys, you just cannot compare one car design to another unless you have a full and complete understanding of both designs.

Having a FULL understanding of said designs is impossible without having access to ALL of the engineering data on said designs from both manufacturers.

Now lets bring this thread up from the grade school level and stop comparing apples to oranges and then complaining that they are not alike.

Bill
Okay. I'll make a note of that. VW CR diesels have design differences that make them special and anything you thought you knew about diesel engines does not apply to the VW CR diesel. Thanks again.
 

frugality

Top Post Dawg
Joined
Sep 19, 2003
Location
Spring Lake, Michigan
TDI
none, 2016 GTI
It may well be that VW is ahead of the curve in making water separators obsolete.

The other manufacturers may be continuing to use water separators, but how many MB and Powerstroke folks are actually collecting any water in them? Any?
 

Ski in NC

Top Post Dawg
Joined
Jul 7, 2008
Location
Wilmington, NC USA
TDI
2001 Jetta ALH 5sp stock
In my industry (marine diesels), WIF sensors have proven unreliable. Too many false positives. A little filament of snot across the elements looks the same as a bowl full of water. So operators disable.

And the tdi's DO have a water separator. It is the fuel filter. On the mk4's, the screw drain tells you if there is any water. I crack mine open each oil change or before a big trip. Most I have ever gotten out was less than an ounce. Later models no bottom drain, but you can pop the lid and look. It's not like these things are running naked.

Still would like something like a little Racor 500 in engine bay. One glance at the bowl tells you what your fuel quality situation is. Snot and/or water readily visible.. in a single glance. Hard to fit in tdi bay, though.
 

dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
It may well be that VW is ahead of the curve in making water separators obsolete.

The other manufacturers may be continuing to use water separators, but how many MB and Powerstroke folks are actually collecting any water in them? Any?
Maybe too far ahead of the curve. With the biodiesel percentages and availabliity growing across the country and one of main concerens with bio being water. I still think there would be a benifit to having a water separator and wif sensor. It sure would have helped warn the owner of this car.

 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
There was NOTHING unique about the Mk4, Mk3, Mk2, or any other "water" drain on the bottom of the fuel filter. It is not a separate chamber on the bottom of the filter, just simply a drain on the bottom of the filter.

Unless you get really crappy fuel, just because liquid comes out the "water drain" of an ALH does not mean that it's all water. If you leave the drain open long enough, you'll drain all the fuel out of the filter.
 
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dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
Do you think VW hasn't used a water separator in years, because it isn't necessary, or because it is cheaper for them to not put one in there?
The VW CR fuel filter had a water space at the bottom of the fuel filter in the two hole fuel filter canister style. Once VW went to the one hole fuel filter style canister and filter the water space was lost because of a shorter canister. So,I'm not sure what you mean when you state that "VW hasn't used a water separator in years" Because they did have a water space as late as 09 MY. There is a water space at the bottom of the two hole style fuel filter canister for water on
the 09,and there is also a non functional "water in fuel symbol" on the instument cluster of the 09's just above the center of the tach IIRC. The symbol could be seen by shining a flashlight onto the instrument cluster. I'm not sure if the 2010 and later MY's have this symbol on the instrument cluster.


The below symbol is similar to the symbol on the 09 cluster. A pic of a fuel pump w/ H2O on it.
 
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red64chevelle

Veteran Member
Joined
Jan 17, 2007
Location
Coventry, RI
TDI
mk6 Golf TDI, mk4 Jetta TDI, Beetle TDI
So, can we add one? I have thought about installing the earlier CR fuel filter so that I would get the vent in the middle that you can use a mitty-vac to suck out any water. Or could you just weld a drain screw onto the bottom of the fuel filter housing? It is a pain in the axx to pull the filter just to check for water.
 

2micron

Vendor
Joined
Mar 23, 2012
Location
Canada
TDI
None
Hello Everyone!!
First timer here and glad to see such a nice “Family” related to TDI’s.
I just bought a 2010 Wagon, 6 speed about 2 weeks ago from a very good VW dealer in Ottawa Ontario. The car was traded in with 50,000 km’s on a new DSG wagon. After driving it 200 km’s, I set about adding better fuel filtration, in attempts to prolong HPFP life.
This is my first TDI, but not my first diesel. Most diesel’s have a means to separate and detect water in the fuel, as well as fine micron filtration. Modern CR engines require 2 Micron filtered fuel. To properly achieve this, primary and secondary filtration is one of the most accepted practices. As for water in fuel, this may not be as common today due to better practices, fibre-glass in ground storage tanks as well as plastic tanks on our cars (to reduce condensate), but it can still happen. My wife’s Cummins Diesel was only weeks old when it got a helping of water. The water separator and warning light prevented disaster. A simple filter drain, then a $45 filter had it back on the road. The station was a well used and a reputable company, but unfortunately, water still made it into their tank. Dweisel’s comment is correct, “Every fuel system needs all the protection available.” It doesn’t matter if your fuel has been refined at the best facility in the world, contamination is possible between transfers. It has been proven, our HPFP’s have issues, so water separation seems like a worth while investment and appears to be a simple item to solve.
Back to filtration:
The stock VW / Mann filter appears to be 7 micron. - any thoughts??

Regardless, if it is less, this would be hard to achieve with a single pass. Again, our HPFP’s seem to be having a tough job with our fuel. Better filtration will not solve the HPFP failures, but it will definitely reduce the risk and possibly prolong the life of the HPFP. This also seems like a worth while investment and appears to be a simple item to solve. Our systems have been designed with critical pressures and flow rates, which, if altered, must be within acceptable parameters.

Here are my car’s fuel system specs, proven by testing with ½ tank fuel, warm spring temperature:
Stock configuration:
“In tank Lift Pump” - 12psi, flows @ 195 litres per hour. (51.5 us gal/ hour)
“Aux. Boost Pump” - 62 psi, measured right at HPFP.
“Return line to tank, before Temperature loop @ idle” - 9 psi, 159 litres per hour. (42 us gal/ hour)
Enjoy the following pictures, showing the added in line supply filtration and filtration, after the HPFP. Those are Racor 400 series filters / separators, mounted under the drivers headlight. Primary is 10 micron, secondary is 2 Micron. Primary has an improved WIF sensor, eliminating the “phantom“ signals of the past. Both bowls have heaters and water drain ports.

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Racor 400 Series Separators. 10 Micron Primary, 2 Micron Secondary. Heaters, Improved Water in Fuel Sensor and Drains.

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Mounting Bracket, with Stainless 3/8" lines.

.

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Filters mounted under drivers headlight, using stock studs. No holes drilled or any alterations to body or frame. Plastic Fender wells removed for Clarity. When the Belly pan is removed, Filters are easy to get to, otherwise, small holes are drilled and plugged in belly / pan to access drain valves.

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Here is the Filtration set up after HPFP, going back to the tank, showing Differential Pressure Gauges to monitor Filter Condition. This filter has a handy drain valve as well, to monitor contamination from our Famous Aluminum Bore / Soft roller HPFP.

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Temporary Gauge during testing after Aux. Boost Pump. 62 PSI at manual energizing, idling or 3000 RPM's

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Here are the fuel system specs, with the added filtration:
“In tank Lift Pump, with primary 10 micron and secondary 2 micron filtration” - 12 psi, flows @ 180.5 litres per hour. (48 us gal/ hour) - 7% decrease in flow, from stock.
“Aux. Boost Pump” - 62 psi, measured right at HPFP. - No change from stock.
“Return line to tank, after HPFP Filtration and after Temperature loop @ idle”- 9 psi, 159 litres per hour. (42 us gal/ hour) - no change from stock.
So the only concern is the 7% reduction in flow from the in tank lift pump, feeding the auxiliary boost pump. This does not mean I have to drive 7% slower, or will use 7% less fuel or will even starve the HPFP. This simply means a 7% reduction in feeding the stock fuel canister, which the Auxiliary boost pump draws from, thus, feeding the HPFP. In testing, results show the return line to tank flows at 9 psi, 159 litres per hour. (42 us gal/ hour) @ idle. The modified filtration system flows @ 180.5 litres per hour. (48 us gal/ hour)
What does all this really mean??
The stock system has 36 litres per hour (9.5 us gal / hour) surplus @ idle, returning to the tank.
The added filtration system has 21.5 litres per hour (6 us gal / hour) surplus @ idle, returning to the tank.
I can’t test pressures and flow rates under load, but road tests have so far been successful. The tank is now less than 1/8 and I have done long WOT runs, up hill with no effect.
For the 3.5 gallons per hour I have lost, I will gladly take the extra 2 Micron filtration and water separation. This also filters the return from the HPFP to the tank. This filter has a handy drain on the bottom to monitor HPFP degradation.
I will update with future tests.

If this interests you, please don’t just try any filters because you found them. Flow rates and pressures must be kept as close to stock as possible. Research flow rates and do your own testing. I would not recommend this project for everyone. I will happily discuss and help.
Negative comments are also appreciated, but the following have already been considered:
1.) Yes this will most likely void the warranty.
2.) 2 holes need to be drilled in the lower fender skirt / belly pan to access water drains.
3.) Heaters will draw 10 amps.
4.) Mounting of a indicator light needs a home on the dash. ( I will drill the blank switches beside the traction control switch)
5.) The filters are in a vulnerable location as far as leaks. A leak may drip onto the tire’s path. A simple catch containment system with a remote drain hose (Tide detergent bottle with a hose) is in the works.
6.) This modification does not seem to put any additional load on the in tank lift pump. It has been stated in past posts, it has a relief valve internally and testing has shown no change in it’s amp draw. There is also simply no change in audible pitch.

Please let us not bicker whether water separation and filtration is important or not. For me, I would rather reduce the risk, than worry about it or criticize others thoughts and beliefs. I have satisfied myself with this modification, more testing will prove it’s worth. I will update as miles add up!! I will post more pictures of the Filters if any one is interested.

The next step is to simplify the Return Filtration circuit. I can now Eliminate the Gauges and add more miles. The Stock Temperature Re-circ. is also on the Chopping block. The heaters in the Racor Bowls will soon take it's place...More testing!!

As far as the HPFP, an Ebay Pump is on the way, for dis assembly and modifications. Many a member has seen these pumps and made comments. It appears better materials are in order - at minimum, a steel liner.
But that is another post.

All the best,
 
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