Lifespan of the fuel injection system depending on diesel quality?

Hello.

I would like to know if there are any guidelines or estimates for the lifespan of the fuel injection system, based on "simple" properties of the diesel fuel that is primarily used.

Biodiesel can cause some problems, including damaging seals, but on the other hand, it is said to have better lubricating properties than diesel, which could reduce wear.
In France, for example, it is my understanding that 5% biofuel is added to regular diesel. In such a low concentration, could the seals already be affected, or does the positive lubricating effect outweigh the negative?

"A while ago, Gremlin wrote something about 'Poland-Schmirgeldiesel' or something similar."
Considering the work involved from the various components, isn't the amount of dirt that passes through the (original) filter initially "harmless"?
Or does a pump (and/or nozzles) wear out faster if it is exposed to particle sizes that are within the filter range but are significantly below its operating range?

Hi Ulf!

In principle, particles in the lubricant always cause higher wear than lubricant that is free of particles, even if the dimensions of the particles are smaller than the operating clearance of the components.
This is because it cannot be assumed that, for example, the piston in a pump always runs concentrically within its bore; instead, it actually always runs eccentrically, within the range of possible clearance. Consequently, even very small particles can lead to abrasive effects.
The issue also arises in the area of seats (e.g., valve seat, nozzle needle seat, etc.), because there is practically no clearance there. In this case, particles can only be accommodated by the surface roughness. If not, "marks" or impairments of the sealing seat may result.
Another important factor to consider is the erosive effect of suspended particles at high flow velocities, particularly affecting the nozzle outlet openings.

So, please keep everything verschandeln and tidy!

Regards,
Alex.

Absolutely.

Bosch states that the pumps have an operating duration of 2000-3000 hours.
When operating with poor-quality fuels, complete failures have been observed as early as after 180 hours of operation.

As Alex already mentioned, particles cause abrasive effects. Especially when the flow of liquid is redirected, particles accumulate. This happens in all valves and flow control elements. Then, due to their inertia, the particles impact the walls and cause damage.

Other 'foreign substances,' such as those of a chemical nature found in synthetic fuels or plant-based oils, also play a role. These can include free oxygen or free water. Furthermore, the gas pressure within such media is crucial; otherwise, cavitation can occur. There have even been cases where engine blocks have cracked due to cavitation occurring during the redirection of the coolant flow near the thermostat! This is even more pronounced in high-pressure hydraulics. Despite pressures of 1000 bar in the line, locally unfavorable flow patterns can cause the pressure to drop so significantly that it falls below the gas pressure within the liquid.
By the way, the 5% rapeseed methyl ester (RME) in the diesel is approved by the manufacturers, but no more than that!

'These entire injection systems are designed for diesel fuel of a specific quality. Our TDI pumps are having major problems in the USA because the fuel quality there is very poor. You could also design a pump to run on RME (biodiesel), but then you wouldn't be able to use regular diesel fuel anymore.'

CU Gremlin.

Gremlin wrote:

... By the way, the 5% rapeseed methyl ester (RME) in the diesel is approved by the manufacturers, but no more than that! ...

"...and it's perfectly normal in France too!"

Hello,

Thank you for your (previous) answers.

"When dealing with Gremlins, numbers..."

Quote:

Bosch states that the pumps have an operating duration of 2000 - 3000 hours. When operated with poor fuels, complete failure has occurred in some cases after only 180 hours of operation.

Extrapolating this, the pump typically fails approximately every 140,000 to 210,000 kilometers (assuming an average speed of 70 km/h across all trips).

. . . and with constant horror fuel consumption, it's already around 13,000 km .

Even though the actual results are often somewhat better, the question remains: where can you find the cleanest diesel at the most affordable price?
Brand-name gas stations probably don't offer much more reliability either, because given today's obsession with money, it's likely that no one in the fuel industry is completely immune to the temptation to steal fuel, cut corners on tank cleaning, etc.

Or am I fundamentally wrong about this?

Alternatively, is it possible to check the cleanliness of the fuel using some DIY tests, so that at least for the foreseeable future, one can hope to get verschandeln diesel from their gas station?

"That just startled me too. My MFA2 memory has already reset 5 times due to a time overflow exceeding 99 hours, bringing the mileage to 19,000 km."
That means 500 hours equals approximately 20,000 kilometers. Therefore, the brake pads might need to be replaced after 80,000 kilometers... ???

Fortunately, they only cost around 400€ each.

Hi,
While specifying a lifespan in operating hours might be useful for an industrial engine, a combined heat and power (CHP) system, or similar equipment, it's not appropriate for passenger cars. For example, the first gear might only last for 10 hours. This sounds alarming, but it applies only under full load. The question is, when and, more importantly, for how long has the engine actually been operating under such conditions? Therefore, even the first gear will last as long as the transmission, provided it's not constantly subjected to full load.
A time specification only makes sense under defined operating conditions.
@Bertil: Can you find that out as well?
Here, and also in advertisements, many cars have over 200,000 kilometers on the odometer, but few have a new pump.

Roger wrote:

...Zum Glück kosten die ja nur ~ 400€/St.

The set (of 4 pieces) is cheaper by €1400 than buying the individual items.

christians wrote:

@Bertil: Kannst Du das auch noch in Erfahrung bringen?

What should I find out? I think I'm having some trouble today .

@Bertil:

Quote:

The set (4 pieces) is cheaper by €1400 than buying the individual parts!

Phew, we just got lucky again. Otherwise, it would have been really expensive ...

Hi Bertil,
I meant, under what conditions, such as load, speed, or type of vehicle - generator, does the lifespan in hours specified by Bosch apply?

Hello,

Thank you for your (previous) answers.

'When dealing with Gremlins, numbers...'
Bosch states that the pumps have an operating duration of 2000 - 3000 hours.
When operated with poor fuels, complete failure has occurred in some cases after only 180 hours of operation. Extrapolating this, the pump typically fails approximately every 140,000 to 210,000 kilometers (assuming an average speed of 70 km/h across all trips).

. . . and with constant horror fuel consumption, it's already around 13,000 km .


I think you're misinterpreting the numbers here. Usually, a lifespan is specified by saying something like: 'The pump will last 3000 hours with a failure probability of x%.' This x% is determined by VW or someone else.

That doesn't mean that all the pumps will break after 3000 hours, but rather that, after 3000 hours, at most x% of the pumps will be defective. I don't know what the value of x is. If x is 1%, then after 3000 hours, out of an initial 100 pumps, 99 would be working and one would be defective. Therefore, the calculated 'horror numbers' are somewhat exaggerated.

Is a 'betriebsstunde' not simply equivalent to one hour at full load?

In other words, driving for 2 hours at 50% power is equivalent to one hour of operation.

That is at least the case with airplanes and agricultural machinery.

christians wrote:

Hi Bertil, ich meinte unter welchen Bedingungen wie Last, Drehzahl oder PKW - Stromaggregat die von Bosch genannte Lebensdauer in Stunden gilt.

Oh, I see...

I can try to find that out... but I don't work at Bosch, I work for a competitor! However, we should have similar data available here as well.

Varianti wrote:

"The pump is rated for 3000 hours with a failure rate of x%". This x% is specified by VW or someone else. That doesn't mean that all the pumps will break after 3000 hours, but rather that, after 3000 hours, at most x% of the pumps will be defective. Ich weis nicht wie groß die Zahl x ist.

Hi,

Unfortunately, that would be the exact key point here. But even so, the Gremlins specifications read a bit more relaxed .

Bertil wrote:

Der Satz (4 Stück) ist mit 1400€ gunstiger als Einzelteile!

Hi Bertil,

Are these prices for new items or for replacements?
For a calculation of the typical case (if one can even speak of a "typical" case when dealing with components subject to wear in such dimensions), the exchange prices would be of interest. Do you know anything more about that?

ulf wrote:

Hi Bertil, Are these prices for new items or for replacements?

New prices!

Quote:

For a calculation of the typical case (if one can even speak of a "typical" case when it comes to wear parts of such dimensions

), the exchange prices would be interesting. Do you know anything more about that?

So, €1400 is a bit less than the combined cost of a VP pump and injectors. } The comparison is allowed, though.

Bertil wrote:

Also 1400€ sind etwas weniger wie bei einem VP Pumpe und Düsen zusammen. Der Vergleich muss so schon gestattet sein.

Hi Bertil,

Of course, that is allowed .

The question is, how long will PD components actually last in real-world applications?
If I assume 150,000 km for the VP injectors (500 euros) and 200,000 km for the PD injectors (1000 euros), then this results in a total of 83 cents per 100 km for the VP and 93 cents per 100 km for the PD in terms of "injector wear costs" - not a huge difference.

Recently, there was a post (of course, a subjective one) that made me fear that the PD injectors might have significantly shorter lifespans.
I can't find it anymore, but someone (apparently in a new post?) wrote something to the effect that, according to their acquaintances, the PD elements were worn out after 40,000 to at most 100,000 kilometers.