when i hold my revs in neutral between 1500 and 2000 rpms the car shakes slightly. i can watch the steering wheel move back and forth slightly. after 2 grand it dissapears immediately and is as smooth as butter. its not something that has ever bothered me before but i was just wondering if there is something wrong, or if something is balanced correctly...any ideas?


-Matt

 

anyone...either yourself or prev. owner.....ever swapped flywheels on it?

 

My GXL was running shaky as hell at low rpm and sitting at idle. It would stutter a lot at light throttle... ended up being an extremely old O2 sensor causing the problem, something with the air/fuel mixture at light throttle. I might be way off the mark tho, i dont pretend to know much about how these things work.
Also have you checked your spark plugs?

 

new plugs/wires
clean K&N filter
brand new O2 sensor when exhaust was done last fall
oil is about to be changed cause i changed it 2500 miles ago

and as far as i know its the stock flywheel but the previous owner didnt tell me much about the car before i bought it. he wasnt very friendly and i just said FINE heres your money GIVE ME MY KEYS and drove off...got home and found lots of problems so i had a lot of fixing to do...its not so bad now though. i dont really feel like dropping my tranny to see the flywheel though (too cold out) and even if i did i am willing to bet its stock even if it isnt the original because the car doesnt rev any quicker than a normal 7.

anything else you guys want to know?

could be nothing i just wanna make sure it isnt anything internal that is gonna make my engine detonate...

 

detonate or blow up?

yeah I wouldn't want to drop the tranny just to see either and I highly doubt (but you never know) if you could verify the flywheel's home (s4 or s5) through the inspection plate on the bellhousing.....


BTW is this a turbo car - s4, s5?


I would say other than an internal balance issue...which im leaning away from since it smooths up at such low RPM....I would say sticky injectors possibly? causing a rough mixture at low rpm - then once the hit a decent duty cycle they spray finer and shes runs smoother....

Injectors fairly recent?

 

87 S4 TII


havent done injectors but my 720cc secondaries are on their way. they wont change anything though because they are secondaries...maybe ill clean my primaries while i have it all apart...