Rough idle?
Thread Starter
Safety Car
Joined: Feb 2003
Posts: 3,849
Likes: 95
From: Springfield MO
Rough idle?
What would cause this on a 95 a4? I recently replaced the plugs and wires. The problem went away for a few weeks but its slowly coming back. My mpg has dropped off to 15.2 down from 17. No codes are being thrown. Any ideas? Could it be bad o2 sensors?
Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Best thing for you to do is get a scan done if no codes are showing .It will tell you what is good and what is not.Other than that look for vacuum leaks.Do you have the FSM? Check there.You say the problem went away but you mention no problem.Is it the milage? Your going to have to come up with more to go on.
Thread Starter
Safety Car
Joined: Feb 2003
Posts: 3,849
Likes: 95
From: Springfield MO
The idle seems to be getting worse. Its lopes like it has a cam at idle but smooths out when the rpm's rise. The mpg is constantly dropping as well. Other than the idle and mpg it runs perfect, no power loss at all. ??? It seems as though i should be getting better gas milage. My bros's 92 gets around 17-19 mpg and my dads 91 is getting over 20 but mine has never seen over 17.
Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Mine is in the low 20's and I don't baby it.Take a can of starting fluid and start checking for vacuum leaks.Better yet get a Mityvac and do it the right way.Until you get a scan you may not find it.Get the FSM it has a drivability section that might help you.Try this too unplug the EGR and plug the hose car should run fine without it.If it is better then there is your answer.My idle really smoothed out and I found the EGR was not pulling enough vacuum.It may not be your problem but it is worth a shot.
