R107 heater ticking- why?

[koksy]

Hi all,

If I have the blower switched on (hot or cold) on my 1975 350SL, it makes a rapid continuous ticking noise from inside the dashboard... but only when I turn the steering wheel left or right! It sounds as if the noise is coming out of the central blower vents. However, as soon as I turn the fan off there is no more ticking when I turn the steering wheel. Any ideas what may be causing this?

 

[johnboy615]

Could be something as simple as leaves in the heater box. A really good blow out might clear it through for you. Water also causes the same problem but for once we've had welcome little of that lately. JB

 

[koksy]

But that wouldnt explain why it only does it when I turn the steering wheel johnboy...

 

[johnboy615]

Very true. Maybe I should post the specs on before reading and replying! Ooops! Now I can see the question I have no idea at all why it should happen when steering. That is a strange one! JB

 

[Jimmyboy]

This is not going to help at all! But it may be related and I would like to know if anyone else has experienced it: When I have the air-con switched on I get a light ticking sound like a fan bearing running dry. But it is still there when I turn the blower fan off (I thought the air-con compressor clutch disengaged when the fan was switched off). As soon as I turn the air-con off, the sound goes. It goes (or I can't hear it) when I close the centre console vents. It is too light a sound for the compressor bearings and it can't be the clutch bearing as the noise would only occur if the air-con was OFF! It has been going on for a long time and hasn't got any worse. What the devil is it???