Ok I am at a loss right now. I have a 2003 ford expedition 4.6L engine, I just change all of my coils out, check my entire spark plugs (they show normal wear, less than 25,000 miles on them. They are motor craft), Changed fuel pump, fuel filter, Brand new Air filter, Oil (less than 2,000 miles), Clean the IAC, Replace the vacuum hose that connects to the throttle, Check for vacuum leaks, none detected and check (visually) all three motor mounts ( they all appear to good). I don’t have loss of power when accelerating; my rpm do not surge up or down it is pretty much consistent. My problem is that when I come to a dead stop I can feel my car (engine) wobble /vibrate. It is not violent are anything, but it is a wobble that is noticeable. Ran a scan on it and there are no codes, everything looks to be in normal operating range. The gas that I run in the tank is 87 octane (which the manual calls for) that has probably 10% to 20% ethanol in it. I use sam club gas in it. The reason that I am bring the gas up is that when I talk to my local Discount Auto Parts store he suggested that I could have low octane and to use a octane boost. So I tried his suggestion, and to my surprise I saw an improvement. The (engine) wobble /vibrate became less noticeable, but it is still there. Please someone help I am kind of at a lost hear? Any kind of suggestion is good
have the same problem?
Wednesday, April 13th, 2011 AT 1:50 PM