Finally a full investigation report...
Checked coolant temp sensor resistance before starting the engine, at 11C (couldn't get lower in the garage) and it measured 4.7K. After warming up the engine, at the moment when fan kicked in it measured 200 ohms. The reference voltage was 4.95V. All readings, according to Haynes are within limits (resistance to be 180 ohms at 100C, 300 ohms at 80C, 2.3K at 20C and 6K at 0C, ref. voltage 5V). The fan cut in at about two thirds of the gauge scale from mid to hot point and cut out just above the mid point. According to Haynes (for models with A/C) the cut-in temperature (1st stage) is 90 to 94C, and 95 to 99C (2nd stage). Could it be that the 1st stage relay simply skips its turn and then the 2nd stage one does the work? Does anyone know the relays position in the box for the Brava '97 automatic with aircon. model? The manual's picture shows 4 of them ((1)preparation for headlamp washer intermittent device, (2) cooling fan low speed relay, (3) cooling fan high speed relay and (4) A/C compressor relay). I actually have 5 in the box, and an empty slot for the 6th one (for ABS system, I suppose), and I definitely don't have the headlamp washer device... I also don't know which contacts are to receive 12V actuating voltage in order to listen for clicks... BTW, there are also some fuses in the box, I forgot to check them out - stupid...
Also bled the coolant at the heater hose bleed screw, and the coolant poured right after I unscrewed it a bit. Didn't hear any bubbling noise when starting engine, will pay attention next time.
Replaced air filter and sprayed WD40 on the alternator bearing. The engine was idling much smoother this time, or was it just my imagination...? Double checked the noise which made me start this thread, and this time I couldn't notice anything (the alternator bearing?) Some hissing noise is also heard when rotating the wheel when cold, and the it's gone after warming up. Hope this is nothing to worry about.
So, I'll try to inspect those relays in next few days, hopefully I'll get some additional info on them.
Checked coolant temp sensor resistance before starting the engine, at 11C (couldn't get lower in the garage) and it measured 4.7K. After warming up the engine, at the moment when fan kicked in it measured 200 ohms. The reference voltage was 4.95V. All readings, according to Haynes are within limits (resistance to be 180 ohms at 100C, 300 ohms at 80C, 2.3K at 20C and 6K at 0C, ref. voltage 5V). The fan cut in at about two thirds of the gauge scale from mid to hot point and cut out just above the mid point. According to Haynes (for models with A/C) the cut-in temperature (1st stage) is 90 to 94C, and 95 to 99C (2nd stage). Could it be that the 1st stage relay simply skips its turn and then the 2nd stage one does the work? Does anyone know the relays position in the box for the Brava '97 automatic with aircon. model? The manual's picture shows 4 of them ((1)preparation for headlamp washer intermittent device, (2) cooling fan low speed relay, (3) cooling fan high speed relay and (4) A/C compressor relay). I actually have 5 in the box, and an empty slot for the 6th one (for ABS system, I suppose), and I definitely don't have the headlamp washer device... I also don't know which contacts are to receive 12V actuating voltage in order to listen for clicks... BTW, there are also some fuses in the box, I forgot to check them out - stupid...
Also bled the coolant at the heater hose bleed screw, and the coolant poured right after I unscrewed it a bit. Didn't hear any bubbling noise when starting engine, will pay attention next time.
Replaced air filter and sprayed WD40 on the alternator bearing. The engine was idling much smoother this time, or was it just my imagination...? Double checked the noise which made me start this thread, and this time I couldn't notice anything (the alternator bearing?) Some hissing noise is also heard when rotating the wheel when cold, and the it's gone after warming up. Hope this is nothing to worry about.
So, I'll try to inspect those relays in next few days, hopefully I'll get some additional info on them.
