Knocking on 1997 Ford Escort

I drove my 1997 ford escort to the store the other day it ran great on the way there but on the way back it started knocking really bad and had lost lots of power. It still starts right up every time I try but has a hard time idling and has little to no power. Could this be a timing belt issue? it sounds like the valves are knocking really bad , If you have any ideas please let me know it's a 2.0 4cyl engine

Asked by for the 1997 Ford Escort
Check the PCV valve and the hose that connects the valve to the manifold. I had the same issue.
2 more answers
It could be just a bad sparkplug causing all of that. How many miles are on it ?
Had the same exact problem, It was bad spark plugs & plug wires.