99 E320 Wagon Idle issue. No CEL,Codes.
Thread Starter
Newbie
Joined: Dec 2013
Posts: 4
Likes: 0
1999 E320 Wagon Base
99 E320 Wagon Idle issue. No CEL,Codes.
99 E320 Wagon Base.
180K
Having a erratic idle issue at low RPM. At idle 550-650 needles bounces. Not steady. Sounds like engine is missing. From tail pipe miss sound also noticed. At engine under hood miss noticed in engine movement .With Vehicle in drive and foot depressed on brake enough to let car start moving forward,Car tries to bounce forward. At high way speed holding steady throttle, 2500RPM needle will sometimes bounce 50 -100 rpm variance. No bucking or surging felt.
Did the following tune up items as normal maintenance
Replaced all Vacum Lines
Plugs
Fuel Filter
Valve Cover Gaskets
Upper fuel line (engine)
Air Filter
Cleaned MAF and intake tube.
Throttle body cleaned.
Trans Service
EGR Tube cleaned
No excessive movement in engine mounts. But unsure when last replaced.
No pending or stored codes on OBDII. NO CEL. Have reset system 2 times and vehicle driven . All systems monitors in OK status.
Where do I go from here ?
Will the 38 Pin connector divulge more info to me. Such as a misfire on a particular cylinder that the OBDII will not ?
Any help or suggestions would be greatly appreciated .
180K
Having a erratic idle issue at low RPM. At idle 550-650 needles bounces. Not steady. Sounds like engine is missing. From tail pipe miss sound also noticed. At engine under hood miss noticed in engine movement .With Vehicle in drive and foot depressed on brake enough to let car start moving forward,Car tries to bounce forward. At high way speed holding steady throttle, 2500RPM needle will sometimes bounce 50 -100 rpm variance. No bucking or surging felt.
Did the following tune up items as normal maintenance
Replaced all Vacum Lines
Plugs
Fuel Filter
Valve Cover Gaskets
Upper fuel line (engine)
Air Filter
Cleaned MAF and intake tube.
Throttle body cleaned.
Trans Service
EGR Tube cleaned
No excessive movement in engine mounts. But unsure when last replaced.
No pending or stored codes on OBDII. NO CEL. Have reset system 2 times and vehicle driven . All systems monitors in OK status.
Where do I go from here ?
Will the 38 Pin connector divulge more info to me. Such as a misfire on a particular cylinder that the OBDII will not ?
Any help or suggestions would be greatly appreciated .
MBWorld Fanatic!
Joined: Oct 2007
Posts: 1,564
Likes: 19
From: SoCal
98 Brilliant Silver E320 Wagon
There are OBD codes for misses by individual cylinders. You might learn more with a Star C3 instrument but only if it's working correctly and you know how to interpret the results.
One thought is throttle position sensor. It is located just inboard from the jumper connection box. It sends a signal that you are pressing on the gas when you aren't.
One thought is throttle position sensor. It is located just inboard from the jumper connection box. It sends a signal that you are pressing on the gas when you aren't.
Thread Starter
Newbie
Joined: Dec 2013
Posts: 4
Likes: 0
1999 E320 Wagon Base
Wires replaced on 12-18. Brake light switch replaced .
Idle now smooth . No more surge or jerking at low rpm. Still a variance of 25rpm + or - . Acceptable for me on a 99 with 180k. Drive and enjoy . Anyone having same the issue I would recommend replacing the items I serviced including wires. Parts cost $600
Idle now smooth . No more surge or jerking at low rpm. Still a variance of 25rpm + or - . Acceptable for me on a 99 with 180k. Drive and enjoy . Anyone having same the issue I would recommend replacing the items I serviced including wires. Parts cost $600
