brulaz wrote:
NinerBikes wrote:
...
Quality of lubrication in diesel fuels does vary. If you want a little piece of mind, don't hammer on the throttle on and off, roll your foot into and out of it gently on these HPFP's, trailing throttle fuel pressures on these is absolutely brutal load and pressure wise on these pumps, and always supplement your fuel with a pint of biodiesel per 12 gallons of fuel pumped into your fuel tank, at a minimum, a qt per 12 gallons would be better.
There's really no excuse for having to baby these Bosch CP4.x HPFPs.
When we replaced our 2005 Passat TDI (still going strong in our daughter's hands), we didn't go diesel in part because of all the stories over on TDIclub.
You would think it's been sorted by now.
There's really no excuse to slam the throttle open and shut on ANY diesel motor on a car or a truck. The history of diesel motors has always been that they are motors BY DESIGN, for steady state use and throttle application. Think boat motors, train motors, generator motors, anything heavy industry designed to run 24/7.
Your assumption is incorrect. The motor and the fuel is by design for steady state use. Do some research on the history of diesel fuel and diesel motors. It's diesel engine operators that have been raised driving gasoline engines that never learn this basic tenant, and assume, incorrectly. I currently own 3 VW TDI's with common rail motors, and to date, knock on wood, I've had zero HPFP failures, and I have my doubts that due to how I drive, that I ever will with that Bosch CP 4.2 HPFP. Because I have done the research and I understand it's design limitations, as well as what constitutes abuse, and what is normal driving applications. I roll my foot into and out of the throttle, I don't slam it, or do anything to spike the fuel rail pressures that the HPFP has to supply, which is what all the enthusiasts over on TDIclub that have problems, seem to be doing, in their jetta's and jetta sportwagens. It seems to be the young guys in a hurry that blow up their pumps. You can tell by their other posts that many of them drive aggressively. That is not conducive to a diesel engine, rapid throttle changes. Roll your foot into it, don't slam it to the floor.
The problems over on TDI club have to do mainly with 1st generation piezo injection 2000 bar fuel pressure motor TDI's in the 2009-2014 clean diesel VW model Jettas, Jetta Sportwagens, Golfs and Beetles.
The 2nd generation TDI's, as found in the 2012-2014 Passat with the CKRA series motor with solenoid injectors, 1800 bar fuel pressure, and a HPFP with a more narrow bore and longer cam stroke on the plunger of the HPFP, at this point in time, have had very, very few HPFP failures to date.
2000 bar pressure fuel on North American 520 micron wear scar diesel fuel seems to be the problem. Bosch referenced the whole design on German diesel fuel, which due to government subsidies, mandated 7% blend biodiesel fuel as reference fuel for the whole Bosch design of CP 4.X series HPFPs, which is a VERY SLIPPERY low wear scar fuel, around 250 micron or less. The North American fuel markets, due to the oil refinery lobby's, does not blend in biodiesel. The main problem was that early in the formation of the biodiesel industry, QC standards were quite low, and biodiesel was being made out of waste, or garbage recycled, rendered oil or grease trap oil. Running any precision pump on garbage used oil, with poor removal of soaps, alcohol, and poor transesterizing processes, clogged a lot of fuel filters and destroyed a lot of diesel pumps, with water left in the biodiesel fuel from washing and improper drying techniques in biodiesel manufacturing. NO QC made the pump manufacturers and the petroleum industry shy of adding biodiesel, too many corners were being cut, to cut costs in it's manufacture, in North America. Too many hippies being green and driving for free, on fuel made from waste vegetable oil, and evading road taxes, doomed the market.
At one point, when I was making my own biodiesel, I had a hippy that wanted to trade me green bud for biodiesel. Told him I preferred greenbacks instead, something a bit more liquid.
