Can detonation occur when idling from cold?

 

The reason i ask is because i am trying to solve a engine rattle that fits the description used by many for detonation (stones being shaken in a bean can).

 

Its quite loud and rises and fall with the rev's until the engine is really hot.

Could well be the exhaust heatshield rattling?

 

Does it happen under boost? If the car was detonating on idle - it would go into safety boost, is it doing this?

 

Pete

Could well be the exhaust heatshield rattling?

 

Does it happen under boost? If the car was detonating on idle - it would go into safety boost, is it doing this?

 

Pete

 

I had this Pete and the noise went away when the zorst heated up and expanded. Sounded like a bucket of bolts when cold though! Removed the broken heatshield and sorted...

 

Steve

Pete, i wish it had boost its a NA! :(

 

hummm perhaps it is the heat shields then! But then again it does sound quite mechanical and bloody loud. Worth a look though, are they easy to remove?

fwiw i really doubt its detting when cold at idle. If it was and youve run the engine for more than a couple of minutes it would probably have blown itself to pieces.