I have an Audi A6 3.0TDI from 2010 with very low mileage (65000 miles, 105000km) and no apparent engine problems.

I got a note from service about suspicious sound coming from the high-pressure fuel pump. They (local Audi dealership) gave me a price for OEM replacement around 1700 EUR (bit over $2000) for the parts only. At the same time, I can see Bosch aftermarket HPFPs on various web stores for third of that price, like here

A friend who owns a car repair shop says that this sounds too good to be true. And besides, I should add 2-stroke engine oil into fuel and see if the noise disappears. Which I have been reluctant to try so far.

However, makes me wonder what's the deal with these aftermarket HPFS? Is the Audi original really that much better to justify the triple price? Bosch sounds as serious enough manufacturer, so how are they so much cheaper?

  • Have you checked what make of fuel system is fitted?
    – Solar Mike
    Jun 7, 2021 at 16:58
  • It's really hard to say. In some cases an aftermarket auto part may be made by the same manufacturer that make the OEM part. In other cases it may be junk. It can sometimes be difficult to know. A lot depends on the reputation of the retail establishment where you are buying from.
    – jwh20
    Jun 7, 2021 at 19:38
  • My (Skoda) main agent told me that one of the two cooling fans was a little noisy and it should be replaced, to save the inconvenience of an unexpected breakdown. This and other similar events convinced me that they were trying to "milk business" by scare tactics. That may not be the case in your situation. Two years later, no breakdown and still no noise that I can detect. Get another opinion. Jun 8, 2021 at 16:16
  • Has happened to me too. I know one of my old cars is still running fine with the radiator that was supposed to be leaking according to service. Tightening a hose clamp fixed it. I dont think such thing is even a sales tactic, probably just the way they work by the rulebook. Each service operation has a time limit so they just order a part and screw it in place Jun 9, 2021 at 19:51

1 Answer 1


Bosch is almost certainly the manufacturer of the Audi part. Car companies do not make all their own components, they sub-contract some parts out to other companies or buy existing models of parts from manufacturers. When selling replacements the OEM (Original Equipment Manufacturer: i.e. the company that made the part in the first place) often sells their part openly, while the car company stamps their brand on it and sells it for a much higher price, so you can often buy the same part much cheaper.

Dealerships will only sell their own brand parts and will never offer OEM replacements. They cost top money, which is why most on this site - including me - would recommend you go to a reputable independent mechanic and save yourself a lot of money.

  • Indeed the competing Audi/VW workshop gave me a quote on the Bosch pump right away, for considerably higher price than web shops though. But now I know the Bosch will be ok and most likely is the same thing. Interestingly, the EU law allows consumers to go to brand service with their own parts but I will not put it to test this time. It would probably be like bringing them a dead cat in a box Jun 9, 2021 at 19:41

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