93 dodge shadow 2.5 na bone stock. Starts and runs but has almost a pre ignition dieseling/ knock. When it's running it's fine. Just got the car so haven't gotten to dig into it far yet. Has 112k on the clock and from what I'm told never had the head gasket done. I also have an issue with fluctuating coolant temperatures. New radiator thermostat and cap were put in. I redid the thermostat thinking that it was bad and it still fluctuates considerably but never overheats thus far. Seem to build very little pressure also. I did a compression test while it was warm and got 145-150-150-150 for 1234 in that order. Will be doing a coolant pressure test soon and a cold compression test. Also will be redoing vac lines seeing as they are slightly cracked. Thinking about deleting the egr and hot air intake at that time also. Thoughts? Thanks Brandon