Water pump GRAF or Pierburg

My car had a Pierburg on it for over 100k miles and 12 years. It still worked great before I replaced it out of caution.

I have over 200k on the Graf I installed at 120k miles.

I have a Graf and I haven't had any problems.

I have 27K miles on a Graf with no complaints.

I installed the aluminum pump (Graf) on the wife's Tiguan and it has worked great since. Have put 40K miles on the metal pump and no issues.

I went with the all metal Pierberg pump for my E90, with an N54. The problem with the plastic is that it gets brittle due to thermo cycling, and that is s problem for all of the plastic parts in these engines (valve cover, radiator, expansion tank etc etc). I probably only have 10-15k km on this one so far, but no problems to report and some very long driving days.

However the pierburg shouldn't crack as it's all aluminum. That doesn't mean it'll last any longer. My original one (n54) failed at about 60k. Replaced with factory. Then replaced that one with pierburg as I was doing oil pan gasket and figured might as well since I'm in there at about 90k. The pierburg one failed at 10k miles (electronics jammed up somehow…I’m guessing some sort of freak surge or something as it’s a pretty simple design). Anyway replaced that with pierburg again and going strong albeit it’s only been 30k miles on the new one.

Well, all of these seals are not created equal in my experience. I have had a bad experience with some seal kits that had combustion chamber seals that were really hard so they didn't stretch evenly over the injector or compress properly with the proper tools. Luckily I was able to source some of the correct ones from a tech friend the same day, so I was able to get my car going. You really need to make sure that you have the right ones, as you have to destroy the old ones to remove them, and if the new ones aren't right, you are screwed. I personally won't recommend anything other than factory parts, as too many times I have tried something else, like Graf aluminum water pumps (two failures-100%, within six months) and gotten burned.

graf has failed on me twice prematurely

I just had to deal with a Graf pump failing at 6000 miles on my CRUA. Everything is low quality trash now.