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:
“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.
Racor 400 Series Separators. 10 Micron Primary, 2 Micron Secondary. Heaters, Improved Water in Fuel Sensor and Drains.
Mounting Bracket, with Stainless 3/8" lines.
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.
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.
Temporary Gauge during testing after Aux. Boost Pump. 62 PSI at manual energizing, idling or 3000 RPM's
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,