Brief Tapity Sound On Cold Start

[Alfa156Melb 9]

Smaky,

 

I've noticed that on the odd occasion, after the car's been sitting for the night, on the first start for the day, there's a very brief tapping sound - it only lasts half a second and goes away. It's only happened two or three times and never happens on any subsequent starts for that day.

 

The engine has done about 70,000kms, the oil is 8,000 kms old (due for a change) and its a POA/Ester blend.

 

I'm wondered if it might be the variator, but it was replaced when i bought the engine, about 30,000kms ago. Besides, its sounds more like tappets to me.

 

Given the oil isn't that old, and the engine isn't that old.. what do you think the most likely cause of this?

[Smaky 73]

Probably a cracked exhaust manifold around the #4 port

[Alfa156Melb 9]

ahhhh. the old cracked exhaust manifold on number 4 trick.

 

But would it then tap away on every cold start or is my symptoms typical of this?

 

Wait... manifold... i have a feeling that's an expensive fix.

 

edit: Come to think of it, i can still hear a tinkling sound under acceleration. Particularly when along side concrete barriers as the sound reflects back... its sounds like little tiny screws being shaken in a glass jar.

 

I've checked all the heat shields and they are good and I recently had new flexi pipe fitted...

 

I've been wondering if this is what pinking sounds like (never heard it before so i dont know) - its sounds very metallic.

 

Would this possibly be related?

Edited February 25, 2013 by Alfa156Melb

[Smaky 73]

ok i WONDER IF IT'S THE PRECAT SUPPORT BRACKET WHICH IS CRACKED???

[Alfa156Melb 9]

Ill check and see.. Cheers