Occasional metallic banging on start up from cold

[Bobby Dandruff]

I have a 2009 Gran Turismo 4.2 which occasionally (5 times in fact since I got the car in late December, as I have been counting) makes a loud clanging noise briefly on start up. It only seems to happen when the car is cold and hasn't been used for maybe 2 days, but is loud enough to be quite alarming.

It seems to come from underneath the car and is metallic sounding (like metal on metal). It goes after a few second and the beautiful roar of the engine takes over but it can't be right. The car is garaged every night and has only done a couple of hundred miles since I bought it.

Maranello weren't able to reproduce the sound but have suggested that it MAY be something to do with the variators.

Does anyone have any views or opinions on this, as I'd like to get it sorted out?

Thanks

 

[Felonious Crud]

It *could* be the valves closing. They start open and then close after a few seconds. It's what gives the car its wonderful roar when you first start it and before it settles down. The noise is more of a metallic rattle / ticking than a metallic bang which lasts a second or two, but it's all I can think of off the top of my head.

 

[conaero]

Well, I think you have an exhaust or exhaust heat shield issue. As the exhaust gets hot, it expands and rattles sometimes go.

To be on the safe side, have your cats checked for break up and also, it could just be a large stone or rock stuck up underneath somewhere.

Let us know how you get on.

 

[Felonious Crud]

That's a good thought, Matt. I had a loud metallic rattling under mine which turned out to be a loose heat shield. Did it all the time in my case. Quick bit of work with a spanner and it's been fine ever since.

 

[roger102]

Check your oil

I have a 2009 Gran Turismo 4.2 which occasionally (5 times in fact since I got the car in late December, as I have been counting) makes a loud clanging noise briefly on start up. It only seems to happen when the car is cold and hasn't been used for maybe 2 days, but is loud enough to be quite alarming.

It seems to come from underneath the car and is metallic sounding (like metal on metal). It goes after a few second and the beautiful roar of the engine takes over but it can't be right. The car is garaged every night and has only done a couple of hundred miles since I bought it.

Maranello weren't able to reproduce the sound but have suggested that it MAY be something to do with the variators.

Does anyone have any views or opinions on this, as I'd like to get it sorted out?

Thanks

 

[Felonious Crud]

Engine or gearbox as well, Roger?

 

[roger102]

engine, mine did that, oil low, added oil and now it's OK

 

[Bobby Dandruff]

engine, mine did that, oil low, added oil and now it's OK

Thanks.

This is just a thought, but bearing in mind that the car has been recently serviced, before I bought it, and it was at Maranello's yesterday (who I assume would make such a check) isn't it unlikely to be something as obvious as engine oil?

 

[Felonious Crud]

Worth a check. Run the engine up to normal operating temp, leave it 5 or minutes and then take the oil reading.

 

[roger102]

LOL don't assume anything!

Thanks.

This is just a thought, but bearing in mind that the car has been recently serviced, before I bought it, and it was at Maranello's yesterday (who I assume would make such a check) isn't it unlikely to be something as obvious as engine oil?