Hey it's been a while since I've been on here! I've been having an issue with my 99 max SE. It started a couple months ago when I noticed my mpg starting to slip 25-50 miles per fill up. I usually fill up around a quarter tank. I had a wheel bearing start to go out and start rubbing. During that time I noticed a very slight pinging sound kind of similar to a idling diesel engine. I ran in to a couple issues replacing the bearing and due to some other drive train/ steering issues the car sat for two months. (I replaced both CV joints and the inner and outer tie rods) After I got the car running again I noticed the same pinging noise was still there. I drove the car through a 3/4 of a tank of gas which got me 180 miles... The pinging noise has also increased and there is a pretty discernible roughness at idle speeds while the car is in gear and stopped. The roughness feels almost constant with a small shudder at inconsistent intervals usually a couple seconds apart. There also seems to be a rather inconsistent loss of power. Sometimes when accelerating the car feels almost normal. Most often the car has almost a heavy feeling and takes a couple seconds to get going. Ive noticed rpm "jumps" every so often where ill press on the gas and the rpm stays the same for a second before jumping around 1k. The car doesn't feel like its going to stall and stays at a near constant idle rpm around 600-700 after the car gets warmed up. It may jump to 2k for a few seconds after i start the car and its not in gear but drops once I put it in drive. I've checked the codes and nothing is coming up. The exhaust also seems to be a bit inconsistent. From checking other posts I've been leaning towards a possible Coil failure. I've replaced the 3 rear fuel injectors, rear valve seals, rear spark plug seals, pvc valve, egr valve gasket and intake upper intake manifold gasket in the last year or so. The spark plugs where replaced about 2 years and 15-20k miles ago with platinum's. I know that the car needs an alignment and its been about 3400 miles since my last oil change but I'm hoping to fix the problem before I get either done just in case. I have a new air filter being delivered next week. Any thoughts? Thanks for the help!

 

My guess is that a coil's on it's way out.