UK-POLOS.NET - THE VW Polo Forum

Got a leak coming form the top bolt (head seal part) on my mk3 1050 genesis. Took the unit apart yesterday and the o - ring and housing seems in good condition but the groove that the o-ring sits in has a gap of about an inch at the bottom.

Is this supposed to be like this or is the groove supposed to go all the way round with no gaps?

Cheers for any advice ...............

did u manage to get the answer u wanted coz i am experincing the same leak cumin from top bolt so i rekin it wud need some sort ov sealant on there or possibly new ring dude

Its a common failure on these - The thermostat housing cracks around the bolt mounts and leaks and it just gets worse over time. Cheapest and most effective solution is to just buy a brand new thermostat and thermostat housing from GSF and replace it all

Im about to change out the thermostat housing and thermostat.

Do i need to apply some type of sealant between the housing and block?

The thermostat came assembled already, should i remove, apply sealant and reassemble?

thanks

There isn’t a need to but a sealant such as Hylomar Blue can be used