Coolant System Problem Options

[80gumdrops]

Howdy. Got a UK '96 ST202 3S-GE.

Firstly, when I start the engine I can hear air bubbles circulating around the cooling system (happens about 3 seconds from ignition).

I've checked that the coolant is fully topped up.

On two occasions I haven't heard any bubbles.. when that happens, no hot air comes in and the engine temp rises above normal. When this has happened I've felt the pipes and found that the top pipe and top of the radiator is hot and the bottom pipe and bottom of radiator is cold.

First time it happened I decided to get the thermostat replaced.

Second time, I added coolant and gave the pipes a squeeze, which must've dislodged some air, because it started working again.

Last night, I heard a few bubbles as usual and had heat as usual, but about 5 mins into the journey I gave it some welly up a hill, lost hot air and the engine started to overheat again.

After a 5 min rest, I started the engine and heard LOADS of air bubbles circulate.

Any ideas folks?

Cheers.

[delusionz]

also sounds like the cooling system is full of gunk

heater should work the best when its overheatin

start by flushing the engine and heater core (under pressure-so throttle the other hose with your hand, make sure you direct water both in and out), change t-stat and rad cap,

dont bother parking up a hill, just run the motor with the heater on hot as you top it off slowly, give the hoses a few squeezes to expel bubbles, put the cap back on when the coolant level is at the top, then fill up your overflow half way and let vacuum take care of the rest. if you have to do anything else to get the bubbles out then you got other issues