Auto box 'ticking' when car parked (when just been used)

[sunking101]

Hi, as the title of this thread suggests, my car seems to tick when parked after a run - seems to be coming from the auto box. It appears to be some sort of heat thing, is it normal?

 

[996jimbo]

It's the metal contracting as it starts to cool down, or maybe expanding a little as it heats up 'cause there's no air moving to take heat away. Probably a bit of both with the ticking caused by the differential movement. Either way it's perfectly normal.

... unless of course it's doing it more than is perfectly normal due to excessive heat build up which is a little difficult to judge over a message board!

In the absence of any other symptoms I would assume it is perfectly normal.

 

[blassberg]

Hi, as the title of this thread suggests, my car seems to tick when parked after a run - seems to be coming from the auto box. It appears to be some sort of heat thing, is it normal?

Hi Sunking.

What leads you to the auto box conclusion? Head underneath and coming from that direction? And this is after turning off the engine? For a couple of minutes?

 

[sunking101]

Hi, thanks for your replies. It does it after a run, when the car is parked and the 'ticking' goes on for around 10-20 mins. It does sound like a metallic expanding and contracting noise but I just wondered if it was normal behaviour. My last Merc didn't do it but this one does! Which car was displaying the more 'normal' characteristics? PS, the noise does seem to be eminating from the gearbox area but the catalytic converter is also around there. It's not the worst noise I've ever heard, it doesn't make me think that something catastrophic is happening but then again as my last car didn't do it I am perhaps a little concerned.

 

[tom7035]

Most likely to be contraction of the exhaust system. The cat especially runs very hot indeed. I wouldn't worry.