Maybe hydraulic lifters might be buggered as they make a rattle if knackered
To me the noise sounds like its pining buts thats normal when you give the motor a quick stab coz of the rush of air going into the motor. If you have had the ecu MAFless tuned the tuner will have to adjust the settings for the MAP sensor and TPS to react faster.
I pulled the starter out and have found some marks on the heat shields where the exhaust has rubbed them, so I'll modify them to rule them out. I'm sceptical in regards to it having something to do with the tune as it started about 30klms after the tune. But you never know! I have checked the torque converter bolts and they are tight. Process of elimination I think!!
Cheer for your input guys
1998 GU TI LS1
Problem solved!!! It was the IAC Valve. It was dirty and sticking when the engine got hot. Cleaned it and the noise has gone.
Thanks for all your input guys, I appreciate it
Cheers
Troy
1998 GU TI LS1
04OFF (11th September 2013)