VW Polo 1.2 2004 - Tricky coolant leak - Themoose
Hi all. My polo has been losing coolant for around 2 years now and I’m struggling to find the source of the leak. It needs topping up around once a week (I drive for around 30 minutes each day). There is no visible leak from the car when cold or hot, and the entire system has been pressured tested when hot and cold by both the AA and an independent garage. I’ve also had a sniffer test performed on the expansion tank to check for a blown head gasket, and the result of this suggested that all was fine. Over the last 2 years there has been no sign of the oil becoming milky, so this also suggests that the head gasket is intact. There is no sign of moisture in the interior of the car, and I can’t see any white smoke or feel any moisture coming from the exhaust My local garage’s suggestion was to just wait for the leak to become worse and then bring it back, but I’m not entirely happy with that, I’d really like to get it sorted. Does anyone have any good ideas about what might be going on? Thanks!

Edited by Themoose on 05/11/2017 at 16:12

VW Polo 1.2 2004 - Tricky coolant leak - Simon
How much coolant do you put in each week? Does it drop below the minimum level if you leave it long enough?
VW Polo 1.2 2004 - Tricky coolant leak - Themoose
It will drop from the max mark to far enough below the min mark to trip the sensor and put a warning light on the dash. I would estimate that it’s around 400-500ml per week.
VW Polo 1.2 2004 - Tricky coolant leak - blindspot

just had the same thing, traced it the pipe from water pump swelling up when really hot. .look for water high up

VW Polo 1.2 2004 - Tricky coolant leak - blindspot

just had the same thing, traced it the pipe from water pump swelling up when really hot. .look for water high up

VW Polo 1.2 2004 - Tricky coolant leak - SLO76
Most likely culprit is the water pump on these which can fail from 70k upwards. How many miles has it done?
VW Polo 1.2 2004 - Tricky coolant leak - dieselnut

When the engine is up to temperature, stop the car in a safe place at night.

Leave the engine running & turn the heater off so the cooling system is under maximum pressure.

Lift the bonnet & shine a torch around all the components of the cooling system looking for steam, this will show up well in the light if you have a minor leak somewhere.