Water pump GRAF or Pierburg

I have been running the Graf AL pump for about 10k so not long enough to give a full assessment, but the quality was awesome and very pleased with it.

Graf does make an AL housing pump which I used this last time. Time will tell if it holds up better the the Rein plastic AM one installed in the CC.

Had a better look during weekend and the "substance" in the expansion tank looks and feels like rust particles not oil. It does not feel slick. I'll be replacing the pump with the aluminum Graf unit soon, hoping I'll last more than 100k at least.

I ordered the Graf aluminum water pump kit from ECS Tuning and did the job this past weekend. I'm glad I took the intake manifold off. I did some carbon cleaning while I was in there, I was surprised to see how much build up was in there for a 70K engine. I don't really see how I could have replaced the pump without removing the intake manifold

I'm working on adapting these water pumps to a variety of older engines. This one will be going on a Chevy LSx. The pumps support two different control schemes; one via PWM (no feedback) and one via LIN. I will be working on reversing the LIN communications and building a more sophisticated controller soon.

I went to the dealer and after a long discussion about plastic vs metal impellers (they thought the VW branded pump was metal) a nice gentleman at the dealer ordered me a Graf branded aftermarket pump for $100 Canadian all-in.

I bought this KIT from SHOPDAP and it was a breeze to install. The price at SHOPDAP is great too.

As for the aluminum one made by/marketed as Graf, there are a few issues in my experience. First, the rubber gasket from the housing to the block is known to fail by tearing where the link in the gasket between the two passage connect. I think this is because the gasket does not precise fit in the channel for the seal machined into the housing. On the one that just put on an engine I just put in my '12 Tiguan, I cut that link out, effectively making two seals and relieving the tension in the seal. Next, the O ring seal supplied for the temp sensor is known to disintegrate, so I got a factory seal. Last, if your engine has a late water pump currently with the clip that holds in the temp sensor, the two mounting bolts to the block at the sensor will be too short for the aluminum pump housing, so you need to get the bolts for an early water pump. Honestly, as long as you don't have any oil leaks, the latest factory water pump is fine. I generally don't trust aftermarket water pumps, as I have had too many fail over the years (not on these engines, just in general). I used this Graf aluminum water pump as a test. The quality seems good, but time will tell.

Okay, so I installed a new aftermarket pump in my MK4 Jetta 2.0 last year. Went with the seemingly highly recommended GRAF metal impeller pump that many forum members across multiple forums seemed to stand behind... 14K miles later and it's leaking. Anyway, after doing some more research, it seems that it's considerably more common for aftermarket metal impeller pumps (especially GRAF, but seemingly all of them from what I can find) to fail prematurely for some reason...

The stock pump failed back in Feb 2010, so i ordered a GRAF pump with metal impeller from ECS Tuning. Purchase was made on 1/27/10, parts got here on 2/03/10, and I installed pump late Feb 2010. Mileage was 127,257 when pump, timing belt, tensioner were done. In the middle of 2010, a loud grinding started at the front passenger side of the engine. I took everything apart and found the water pump with bearing grease or some waxy chunky crap all over the outside of it and on the inside of the timing belt cover like it splattered, and the pump leaking from the shaft. Car now has 135,362 miles on it, so thats complete pump failure within 8,069 miles.