Water pump OEM FORD or GRAF

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

Graf with the metal impeller. No issues.

I've used Graf water pumps on two different E46s without any issues.

I ordered the kit from urotuning for my gfs 01 golf, been in for almost 2 years now no issues. They use a Graf water pump with a metal impeller.

I picked up a 3.6 brass impeller Graf waterpump for under $50 from www.autohausaz.com they also sell the oem thermostat.

I purchase the all aluminum pump made by Graf from FCP euro, they have a lifetime warranty, free shipping and good prices. I removed the manifold to get to the water pump. I had a problem with the cheap thermostat that came with it. It caused my car to run hot.

My '89 325iX doesn't put out much heat at idle, but as soon as I rev it to 2000 rpm, the heat starts coming out of the vents. At idle it is around 65°F air and at 2000 rpm it goes up to around 95°F (it is ~35°F outside today). I noticed a whistling noise that seems to come from the water pump at idle. Once the car got to normal operating temperature, I noticed that at idle coolant stopped coming out of the bleed hole. If I revved the engine a bit, coolant would flow. I replaced the water pump (Graf) 2900 miles and 3.5 months ago. My intuition is that the water pump isn't generating sufficient pressure at idle to move the coolant through the heater core.

16,000 Miles (12 months) and now the Graf is leaking. After researching it seems a few bearing failures, a few thermostats, and some sensors out of the box are failing on these Graf pumps.

I just bought one of these Graf aluminum pumps for an engine that I am building, but before installing it I asked around with the VW tech friends I know what their impression of it is. The consensus was "not great". One shop had to warranty two of them because the seal to the block failed, tearing at a T where it connects the two passages.

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...