Topic

Had a slight problem. As mentioned in a previous post after exhaust flexi and oxygen sensor change there has been the occasional 'burning' smell.... Quite concerned needless to say.... Stuck my head in the engine bay only to hear a sporadic ticking noise.... Has any one got a clue what this may be???


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engine is off or running?

When it happened the engine was off, cheers for responding.....


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The ticking may have to do with the exhaust components cooling which get really hot, especially the catalytic convertor.
Your car's engine is actually shrinking. The various parts are contracting when you turn it off.

J_dubya82 wrote: wrote:

When it happened the engine was off, cheers for responding.....


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The random ticking noise when an engine is turned off will possibly be the thermal contraction of the exhaust manifold, downpipe/flexi and CAT, these exhaust components get extremely when running and expand with heat, when the engine is stopped they cool down quite quickly due to their small mass and large surface area (thin wall thickness of the tubing) this rapid cooling process can often give a random clicking sound until the exhaust components have cooled down and contracted.

Also your burning smell could be the new down pipe and flexi, this will have a surface coating plus any residue of penetration oil or release oil/waxes etc. which will burnoff and vapourise for the first day of use.

Crazy thing is it's happening when the engine is cold.... Like an electronic tick..... Very random different ticks and then may just stop all of a sudden......


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Do you mean when the engine is running on start up from cold?

As well as the usual tappets, the carbon canister also makes a loud ticking at times too.(Black canister beside ecu)