I have a 2005 Continental GT Mulliner, 55,500 miles RHD UK car which has started ticking when sat at idle. The noise is very consistent and ticks slightly quicker than the second hand of a watch, when you lift the revs to approximately 900 RPM it stops. It appears to be coming from somewhere in front of the driver in front of the bulkhead. I’m struggling to establish what is the cause and hope that some can help me identify what it could be?

 

Hello @DaveGT ,
If you could post a video that may help, otherwise we are just guessing...

Does the tick speed up with any increase in rpms, is it like a valve tap, could it be oil pressure related, as in when you raise the RPM a hair it goes away, is it timing chain slap on the VVT, when was the last oil change, are you hearing a fuel injector clicking sound, or a evap control valve clicking, just so many items come to mind, so help us help you.

Johnny

 

My vehicle does the same thing, after some 10 min driving it goes away until I shut off the engine and let it get cold again, I'm thinking in add Sea Foam in the oil before the next oil change, and do an Italian tune-up in the highway.
With only 40k miles in the odometer, I really doubt in my case a loose timing chain.

 

Yours sounds like an exhaust leak

 

An exhaust leak can sound very similar to a tappet or valve lifter noise?
My noise happens in front of the engine, I can hear it more pronounced in the passenger side bank, US spec.

 

Has it ever had the front off to change the serpentine belt ?
Idler pulleys normally get changed as well as theses can get noisy.Like to see a vid thought?
Second the VAG alternator is water cooled .The two rubber o rings for the pipes perish and water seeps out .It can eventually ruin the a bearing .
It will be one of theses .

 

I don't know if the previous owner replaced the belt, since the car is only 40K miles but has more than a decade I think he did it at some point, but I'll check that with my stethoscope.

 

Yes a cracked exhaust can sound exactly like a bad lifter. It will go away as the engine gets hot and the manifold or pipes expand. I have used a stethoscope to pinpoint the noise.

 

That will be the purge valve, it is situated under the header tank on the right hand side (Bank 1) of the engine bay, If you put your ear to the wing around that area you will hear it, to stop it you have to remove it from its mounting bracket and cable tie it to it instead of the rubber mounting it uses.