On our 1997 Golf GTI VR6, the coolant return pump keeps running after the ignition is turned off, any ideas or suggestions for troubleshooting?
it could be the thermoswitch or wiring to it that has failed, its the 4 pin one on the front you want to look atbrown/red and brown wires to pins 1 and 3. make sure the wire isnty shorted, and unplug the sensort just before you switch the car off to see if that stops it. the other 2 pins are for the dash gauge so dont worry that the gauge drops to 0 when unplugged
Is it not really a coolant run on pump? Assuming its the one back right of the head, I thought it was suppost to do that.
Yes, If its the aux after-run pump (Small one of the right side of the head) it's meant to run on for 10 minutes after you switch the car off to keep the coolant flowing.
Thanks all for your puts, yes it is the small pump on the right side of the head, is the run on timer based or temperature based? Problem exists even when cold.
I always thought it would only be triggered when engine is at certain temp from the thermoswitch on the coolant flange, but possibly its an additional switch. so the default is always 10 minutes after switch off, but if the engine is REALLY hot the pump carries on till the thermoswitch cuts out? If I had a VR to test this id have ignition on then off, time the pump. repeat but with the thermoswitch pins bridged see if it runs on for longer, if it does then pull the wire bridge and see if the pump stops