04-12-2018 11:08 PM
Start troubleshooting can remove the engine valve cover and inspect all rockarm, bolt, injector that all parts are in place, some time thoose engine broken the bolt on rockarm.
C7 engine if you find the Check engine litgh on, need a service to check the Engine ECM with the ET the to make some test like cylinder cutout, or some active code.
04-11-2018 08:49 AM
I have a noise that sounds like preignition in a gas motor. It does it mostly on a pull from 1200 RPM. It sounds like something is loose and vibrating but I can't find the cause. Help please.It is in a 2005 GMC 8500.