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.

[Outsider]

I had to change my radiator due to it cracking(was told it was age related). After the change I had NO heat. It took me a week to get cabin heat back. The heater core is in a location that is higher than any other part of the cooling system. It gets one mother of an air lock. It took me a week to get the air out of the heater core. Now it gives off heat better than ever.

[Galcobar]

I had to change my radiator due to it cracking(was told it was age related). After the change I had NO heat. It took me a week to get cabin heat back. The heater core is in a location that is higher than any other part of the cooling system. It gets one mother of an air lock. It took me a week to get the air out of the heater core. Now it gives off heat better than ever.

It's due to the heater core or at least the pipes which run to it that people suggest doing the fill/bleed procedure with the front end elevated -- anything which encourages the trapped air to follow the lines out can speed up the removal of air from the cooling system.

Gumdrops, your description of the problem is reasonably clear, but you're not giving us the sort of useful information when it comes to what you have actually done to diagnose or correct the problem which would allow us to help you with specifics.

You haven't stated whether or not you properly filled (through the cap) the cooling system, then bled the air out (running the system with the heat on full, the cap off until the coolant level stays steady); whether you have to top up the level of coolant in the reservoir; whether you flushed the system prior to filling; test results of the radiator; colour/consistency of the coolant; test results for the radiator cap; etc.

All of the above have been suggested to you over the course of this thread, and can be done in one session.