Evap silonoid

If you sit and let your car warm up, and it is between 1/8 and 3/4 full on gas after about 5-8 minutes you will hear some loud thunking noises. it is on every equinox. I have talked to gm about it and they say it is normal, but the mechanics told me it should not be that loud. They said you should not be able to hear it. If enough people complain about it, they will recall it and fix the problem. So please mention and file concern with your local dealership to get this fixed.

Thank you for your participation

I get that noise (or so that is what they tell me) but I get it very randomly, while I am at stops, right when I start the car, after I have turned it off etc...They looked very confused as I was telling them this and said that doesn't sound like the selinoid if it happening at stops. Hmmm?????