I own a civic VTI 2006 model. CNG kit was installed at 15000 kms. Last week, I had the 20,000 kms checkup from Honda dealership. Plugs, filters, oil, etc were replaced along with first tunning and routine checkup. I went to Islamabad by motorway and noticed a strange whistle like sound as soon as the speed crosses 100/110 KPH. It doesn't come when I slowed to 100 KPH.
I need expert advice on this.
Thanks in advance.