Mbtech
New Member
Hey all, purchased an 01 civic lx 5 speed sedan about 4 months ago for my commute to work and wow has it been a money saver! The only issue Ive had with it is it has been plagued with a rough/almost stalling idle that get worse when the vehicle is warmed up to operating temp or with a/c or any type of load on the engine. The main issue I have is when coming to a stop the engine drops to about 200rpms then revs up to about 1000rpms and then settles at about 600 rpms but not always, sometimes it just barely makes it to 400 rpms and just stays there and has a terribley rough idle, hood shaking, dash shaking, door panels rattling. Also it is not related to clutch engagement or brake pedal engagement either as it will do it in neutral coasting to a stop.I began by searching forums including this one on what could be causing the idle problem and did not find anything that seemed to be as bad as my situation especially having no fault codes. To date here is what I have found/tried/tested:
Spark plug tube seals leaking, replaced seals and valve cover gasket and installed new ngk single platinum spark plugs and installed new honda coil on plugs. Had no effect. Also checked valve adjustment and all were right in the middle of spec.
Replaced throttle body with new throttle body assembly from Honda and performed idle relearn. Had no effect.
Had a fault set for thermostat performance, replaced faulty coolant temp sensor. Had no effect besides no more cel/fault.
Performed cylinder balance test and found no dead cylinders.
Checked compression dry and all 4 cylinders at 135psi wet all at 150 psi ***is this ok? Found different specs between haynes manual, online, alldata etc.***
Replaced all 4 engine mounts with honda engine mounts due to being worn/torn.
Replaced fuel pump because it was cheap and felt like throwing a part at it lol Had no effect.
Installed new gates timing belt, waterpump, and tensioner pulley. Replaced oil pan gasket and crank seal due to oil leak. Timing belt etc. Had no effect.
Tried driving around with upstream o2 sensor unplugged because there were a few people that had a bad upstream o2 and that seemed to work, had no effect. Also checked output voltage using my scan tool and it is sweeping correctly anyways, just figured it was worth a shot.
Removed upstream 02 sensor to see if vehicle ran any better which may point to a clogged up cat, had no effect.
Checked for vacuum leaks and did not find any.
Sorry for the long post but Im about at the end of my rope on this one, I have no idea what else to check.I appreciate any and all insight.
Spark plug tube seals leaking, replaced seals and valve cover gasket and installed new ngk single platinum spark plugs and installed new honda coil on plugs. Had no effect. Also checked valve adjustment and all were right in the middle of spec.
Replaced throttle body with new throttle body assembly from Honda and performed idle relearn. Had no effect.
Had a fault set for thermostat performance, replaced faulty coolant temp sensor. Had no effect besides no more cel/fault.
Performed cylinder balance test and found no dead cylinders.
Checked compression dry and all 4 cylinders at 135psi wet all at 150 psi ***is this ok? Found different specs between haynes manual, online, alldata etc.***
Replaced all 4 engine mounts with honda engine mounts due to being worn/torn.
Replaced fuel pump because it was cheap and felt like throwing a part at it lol Had no effect.
Installed new gates timing belt, waterpump, and tensioner pulley. Replaced oil pan gasket and crank seal due to oil leak. Timing belt etc. Had no effect.
Tried driving around with upstream o2 sensor unplugged because there were a few people that had a bad upstream o2 and that seemed to work, had no effect. Also checked output voltage using my scan tool and it is sweeping correctly anyways, just figured it was worth a shot.
Removed upstream 02 sensor to see if vehicle ran any better which may point to a clogged up cat, had no effect.
Checked for vacuum leaks and did not find any.
Sorry for the long post but Im about at the end of my rope on this one, I have no idea what else to check.I appreciate any and all insight.
