Photos from Billy-Jay Hughes's post

I've done something really fucking stupid yesterday....I did all my levels as you do and some how accidentally forgotten to put the rad cap back on stupid I know . We I drove it about 2 miles before I realised as the water was pissing everywhere no heat in car and the temp was rising right up.

Today I filled the system right back up how ever it's still over heating and the interior heaters are giving no heat when I turn off the engine I can hear a hissing noise !? I can see water around the expansion tank how ever I cant be sure if it's water from filling up or not

Anyone able to help please

%d comments
  • Comma G48 Antifreeze and Coolant C...

  • Cars
  • Guys thank you very much for your very quick and detailed responses thank you il do this tomorrow after work

  • Expansion tank can split and rad cap fail if the system has been over pressurised. You can bleed the system cold if you have the car on (but not engine running) with heaters on full hot (opens heater valve) and literally blow (into expansion tank with your mouth) to push coolant through system with you bleed screw open. In my experience across 10+ bmws this is the most reliable method for bleeding fully. Once you know its properly bled you can then loom for leaking rad caps and expansion tanks. If you still get overheating check the viscous coupling on the rad fan too. Once all that's good it can be other leaks (heater matrix?), a cracked head or blown headgasket causing overheating

  • Hissing noise! Snake in your engine?

  • Air lock mate.. you will need to clear it

  • Remove top rad hose from radiator and slowly, and I mean slowly pour coolant down the hose to fill the block, once the hose will take no more put t back on the rad and fill the rad tank. They are a total arse to bleed but I've had success every time with this method.

  • Need warm water ! Bit nippy out there

  • Don't even have to jack it up just park it facing uphill.

  • Cars
  • The hissing sound is normal my 330 does it