[finhudson16]

I'm after a bit of advice about a problem I'm having with a V50 D3 I've just bought. I bought it with a suspected coolant leak and I've narrowed it down to coolant escaping through the vent on the cap while it's being driven. I've pressure tested the system and the cap works perfectly, it vents at 20psi as it should.

Even after it's cooled down, the system is still pressurised and bubbles up a bit when you remove the cap; given this I suspect that the problem is something over pressurising the cooling system while it's running, causing the coolant to bubble up in the tank and escape through the cap, which is venting due to the increased pressure.

Has anyone got any experience with failed head gaskets causing this? I've got the D3 5 cyl engine which I believe is a de-stroked D5 engine. Parts are really hard to find for the D3 so I'm hoping it's not anything more serious like a cracked block for example.

Does anyone know if there's any parts compatibility between the D3 and D5 engines?

I'm new to volvos here so any knowledge/common faults with these engines would be really appreciated!