I have a s type 4.0 v-8with rough idle, w/ 88,000 miles bought w/64,000 2009. when I bought it I was told it have a oil leak an check engine light on. could not see oil leak but after 200 to 600 miles got engine miss? what I found was oil around plugs. resealed valve cover, replaced plugs and booths royal pain!! the check eng ine light was a acidic converter code had it cleared at time the light would come on and go off had it checked same code, car ran fine did not worry about it. now wife came home told me car not running rite his said it felt like it wanted to die. I thought it may be the same thing oil around plugs so I pulled coil covers off both sides and removed front plugs they were dry and plugs look good. started the engine unplugged right side coil plug engine got rougher then I pulled the driver side front engine did not change? so I swapped the two front coils from one side to the other thinking if the miss would move no change??? so I left the drivers side front coil unplugged and unplugged the 2nd one idle no change.... so I went back to the exhaust pipe the drivers side was not very hot and the passenger side was hot, and driver side was not smooth. so going back to the acidotic code I was thinking I had stopped up converter so I dropped the exhaust at the manifold which was not easy no room to get to the two bolts. after dropping it I started the engine and same thing bad idle. so I put the exhaust back on. now I was thinking by a chance that I should replaced the plugs no change I even took the coil and plug to see if it had spark got my wife to start the engine to check for spark had spark. so now I am thinking start the engine and I unplugged one of the injectors no idle change so I unplugged another injector no change. not sure what to check next !!!!!! a ideas

 

What in the world is a "acidic converter code"???

This means nothing. The real issue is have you changed the timing chain tensioners? If you have not when are you going to do it?

They will fail and the failure most likely will destroy your engine.

Please do not ignore this as you might have already had a failure that caused the timing chain to jump a tooth and that will cause rough idle/running like you have now.
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I also had a rough idle/miss… it was one coil pack, but because there was no engine code i had trouble finding which one it is….so I ended up changing all 8 of them….car ran awesome after that….and hasn't given me any problems in over past 30k miles since i changed them.

 

What should the cylinder compression be at?