Just picked up a 97 Civic HX project car. It runs but definitely needs some love. Already changed the oil and filter, fuel filter, spark plugs. Will be doing a tranny flush and brake bleed/clutch. One thing I just noticed is that at idle only, there is a slight knock on the left side of the engine. It sounds lower down but it doesn't necessarily sound like it's coming from inside the engine. I'm new and still learning how to work on my Honda so any info is appreciated. TIA