coolant bleeding the system,

[daymo69er]

having problems bleeding my system,

if i leave the car running with the cap off the fans dont seem to get hot but the water comming out the bleed screw is boiling, ive left it run for a while but im still not sure, my temp gauge has been plumbed in to the coolant system but doesnt read any temperature,

if i drive it around for abour 10 mins, the temp gauge will go up to around half and the heaters come on fine but i just cant seem to get them hot when trying to bleed the system,

im to scared to leave it run to long incase i blow the head gasket or something? , would it just be worth taking it to the garage to bleed?

any help would be appreciated!

[daymo69er]

oh forgot to say also i got 2 caps for the rad and seems when shes warm theres a hissing from the cap...thats both caps i have that do that would it be worth ordering a new 1.4 bar cap,

[fonk]

are the water hoses getting pressurised after 5min drive? if not cap is faulty.

try to bleed the system with car on ramps or up the hill... well easier to fill heater matrix

[Motorhole]

Disclaimer first - I'm no expert! But running the engine with the cap off won't pressurize the system, which is probably why the water from the bleed screw is boiling and your temp gauge ain't moving! A hissing cap after a drive suggests you have a leak somewhere and air is getting into the system causing it to over pressurize. The hissing is the cap releasing excess pressure.

Best bet is to start from scratch. Drain the system, get the front of the car high, turn ignition on, engine off. Heaters on full hot and fan on. Fill slowly from top hose with the cap on and the bleed screw open. Once water starts coming out of the top hose outlet in the rad, reconnect top hose and tighten bleed screw. Run engine for 10 mins, keep eye on temp and check for leaks. Make sure hoses get hard and hot and that warm air comes from the blowers once the temp gauge starts moving. Turn off engine, loosen bleed screw to release any air then retighten. Then take it for a test drive and on return, loosen bleed screw and retighten once more. Job done