Anyone discovered what that mysterious 'clank' from the gearbox area was?
Posted: Fri May 10, 2019 7:56 pm
I vaguely recall that, many months ago, one or two forum members with 1.2 TSI 6Rs were complaining of hearing a momentary and just-about-audible metallic 'clank' noise coming from the gearbox area of the engine compartment when driving about. Did those who reported this ever find the cause? I've now got the same phenomenon.
Certainly in my case the noise lasts for a fraction of a second but can be heard from within the cabin. It occurs just after the clutch pedal's depressed when changing gear at low speed. Changing gear, per se, isn't a problem; it's always quite smooth. I do, however, always sense a small momentary forward jerk of the car when firing up the engine from cold, after the car's been left to stand for an hour or more.
Could this be something to do with the clutch release bearing setup? I've seen no loss of hydraulic fluid in the master reservoir, but could this noise result from air being trapped in the clutch slave cylinder and then it causing some sort of rebound of the slave cylinder's rod/piston against the release bearing actuator? The slave cylinder is mounted topside of the bell housing, and the release mechanism is just out of sight, inside the bell housing, as I understand it. Is it possible to withdraw the cylinder to inspect it in its entirety, without fear of not getting it back into place afterward? For this 5-speed gearbox, I believe there are two possible designs of release bearing.
I don't think this is anything to do with the dog-bone brace on the underside of the gearbox, a source of a similar noise that's been reported by one or two owners of these 6Rs and 6Cs, as to me the noise sounds as though it's coming from specifically the upper area of the engine compartment. I do lose some minute amounts of 'an oil' over time, which ultimately spill on to the front undertray and thereafter on to the ground, but I haven't been able to identify the oil, as annoyingly all three oils of this car (engine oil, gearbox oil and hydraulic fluid) are of similar viscocity and have the same pale-yellow tinge.
As soon as the weather's conducive, I intend experimenting further with the gear-changing, to see if I can get any additional clues. The gearbox is a PED type.
As matters stand, the cause of the noise isn't preventing anything on the car from working properly. It's just that constantly hearing the noise when driving around - specifically when changing gear - is annoying. Pedestrians' heads turn, so from outside the car it would seem to be quite distracting.
Certainly in my case the noise lasts for a fraction of a second but can be heard from within the cabin. It occurs just after the clutch pedal's depressed when changing gear at low speed. Changing gear, per se, isn't a problem; it's always quite smooth. I do, however, always sense a small momentary forward jerk of the car when firing up the engine from cold, after the car's been left to stand for an hour or more.
Could this be something to do with the clutch release bearing setup? I've seen no loss of hydraulic fluid in the master reservoir, but could this noise result from air being trapped in the clutch slave cylinder and then it causing some sort of rebound of the slave cylinder's rod/piston against the release bearing actuator? The slave cylinder is mounted topside of the bell housing, and the release mechanism is just out of sight, inside the bell housing, as I understand it. Is it possible to withdraw the cylinder to inspect it in its entirety, without fear of not getting it back into place afterward? For this 5-speed gearbox, I believe there are two possible designs of release bearing.
I don't think this is anything to do with the dog-bone brace on the underside of the gearbox, a source of a similar noise that's been reported by one or two owners of these 6Rs and 6Cs, as to me the noise sounds as though it's coming from specifically the upper area of the engine compartment. I do lose some minute amounts of 'an oil' over time, which ultimately spill on to the front undertray and thereafter on to the ground, but I haven't been able to identify the oil, as annoyingly all three oils of this car (engine oil, gearbox oil and hydraulic fluid) are of similar viscocity and have the same pale-yellow tinge.
As soon as the weather's conducive, I intend experimenting further with the gear-changing, to see if I can get any additional clues. The gearbox is a PED type.
As matters stand, the cause of the noise isn't preventing anything on the car from working properly. It's just that constantly hearing the noise when driving around - specifically when changing gear - is annoying. Pedestrians' heads turn, so from outside the car it would seem to be quite distracting.