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General Information => Troubleshooting => Topic started by: jimfoo on April 04, 2007, 07:30:39 pm

Title: AAz overheating, flow direction, water pump
Post by: jimfoo on April 04, 2007, 07:30:39 pm

Ok, I have also had overheating problems in the past. With all the discussion about slipping impellers and such, I decided to take my water pump apart and check it.  Something seems weird however. Which direction should the water pump turn and what is the flow direction through it? Are there different shaped impellers? Mine doesn't seem to be ideally shaped for the direction it turns as far as I am concerned. I am wondering if that is my problem.

Title: AAz overheating, flow direction, water pump
Post by: addautomotive on April 04, 2007, 07:36:16 pm

Same rotation as the crank.

FWIW, I find VWs are sensitive to air locks in the cooling system, especially down at the pump & thermostat. I find filling the block from the upper rad hose helps move the air out. (As opposed to filling from the rad)

Title: AAz overheating, flow direction, water pump
Post by: jimfoo on April 04, 2007, 07:43:24 pm

Were there any that turned in the opposite direction? If so, does anyone have a pic of the impeller?

Title: AAz overheating, flow direction, water pump
Post by: burn_your_money on April 04, 2007, 07:58:41 pm

(http://image.autopartsonlinecanada.com/live/G3000170729GEB.JPG)

I agree, it would seem to work better if it spun CCW

Title: AAz overheating, flow direction, water pump
Post by: jimfoo on April 04, 2007, 08:22:26 pm

Is that a new pump? My impeller has a 1/8" gap from the bottom, yours looks almost flush. Mine almost looks like it has wear on the sides. It makes me wonder if mine had been slipping, and moved towards the end of the shaft, allowing it to rub. Maybe a new pump is in my future.

Title: AAz overheating, flow direction, water pump
Post by: burn_your_money on April 04, 2007, 08:26:41 pm

yes that is a brand new pump, I just stole it off one of the websites I order from frequently

Title: AAz overheating, flow direction, water pump
Post by: jimfoo on April 04, 2007, 08:30:51 pm

Are the same pumps used on the gas engines? If so, maybe I could get one at the local auto parts store. I guess I have a 1.8 sitting around I could check if I can move enough stuff to get to it.

Title: AAz overheating, flow direction, water pump
Post by: jimfoo on April 05, 2007, 04:58:10 am

I got to thinking about one more thing. Do VWs have a valve on the heater line? Since mine is non-VW, my heater doesn't have any valve. This means that some hot water is always being recirculated and never sees the radiator, which can't help my temps much.

Title: AAz overheating, flow direction, water pump
Post by: burn_your_money on April 05, 2007, 08:03:40 am

The MK1s have a vavle that shuts off the supply to the heatercore but after 1984 VW used flaps in the heater box to control the heat, so there is unresticted flow to the heatercore at all times