Overflow coolant bubbling in VR

[Immortality]

Still sounds like it could be a radiator cap. I had similar issues even with a new cap (trident). Eventually fitted a CPC radiator cap and that solved the problem. The CPC cap has a slightly different style of seal.

The engine temp will actually increase slightly when it is first shut down because there is still a lot of heat in the cylinder heads but the coolant is no longer moving to take that heat away. Because of this the pressure in the coolant system will actually increase and if the radiator cap is a bit suspect it will let more coolant out allowing the pressure to drop which will in turn actually lets the coolant boil (worst case).

 

[macca_223]

Thanks immortality. I currently have a trident radiator cap on it. Got it from Supercheap. Might go to Autopro see what brand they have there. Where can you get the CPC cap from?

 

[Wozza]

Holdens or fleabay
Genuine Holden NEW Radiator CAP Suits VN VP VR VS VT VX VY V6 Commodore | eBay

 

[Immortality]

I think I got mine from supercheap.

 

[VS_Pete]

RADIATOR CAP CPC part number 538-20.
RADIATOR CAP CPC HOLDEN part number 92056367