LS1 idle shudder cause ?
LS1 idle shudder cause ? 2002 camaro, LS1, 6-speed, stock, around 68k miles summer driver.
for the last year the idle when stopped as been funny, the rpm's are solid at 800 on the gauge, but you'll feel a shudder in the seat and can watch the shifter move a little. it's almost like an idle with a cammed engine. with hood up looking at the engine you can watch the engine rock left-right as it shudders. year or two ago I got the DTC for air check valves, replaced both of those along with 2 new front O2 sensors. Never had an o2 sensor code. this summer for what little i've driven the car it seemed the idle was really shaky, but the rpm gauge stays solid on 800. other than the DTC for the air check valves way back, car never had any other dtc and runs fine otherwise. I just replaced the IAC valve but that didn't help. don't know what else to look at or try. and it seems to only really happen when the car is hot and you've been driving it then come to a stop. when you start it cold and let it idle the shudder doesn't seem to be there.
for the last year the idle when stopped as been funny, the rpm's are solid at 800 on the gauge, but you'll feel a shudder in the seat and can watch the shifter move a little. it's almost like an idle with a cammed engine. with hood up looking at the engine you can watch the engine rock left-right as it shudders. year or two ago I got the DTC for air check valves, replaced both of those along with 2 new front O2 sensors. Never had an o2 sensor code. this summer for what little i've driven the car it seemed the idle was really shaky, but the rpm gauge stays solid on 800. other than the DTC for the air check valves way back, car never had any other dtc and runs fine otherwise. I just replaced the IAC valve but that didn't help. don't know what else to look at or try. and it seems to only really happen when the car is hot and you've been driving it then come to a stop. when you start it cold and let it idle the shudder doesn't seem to be there.
while putting a new axle in over the winter, i also did the motor mounts and trans mount with new rubber ones. the old ones were completely fine.
i doubt the fuel filter would cause it, i did plugs years ago they are ngk iridium and with less than 50k on them should be fine. the engine hauls so i'm at a loss what could cause this idle issue. correct me if i'm wrong but i don't think the maf would play any part at idle when throttle position sensor is zero, and i thought it's the IAC that controls the idle? the one thing i would agree on that might cause it is injectors, the car does sit every winter for the last 10 years. i did injectors on my truck, pulled them and had them cleaned by marren in oxford, wasn't cheap. And I hate to go through the trouble not to have it solve the problem.
i doubt the fuel filter would cause it, i did plugs years ago they are ngk iridium and with less than 50k on them should be fine. the engine hauls so i'm at a loss what could cause this idle issue. correct me if i'm wrong but i don't think the maf would play any part at idle when throttle position sensor is zero, and i thought it's the IAC that controls the idle? the one thing i would agree on that might cause it is injectors, the car does sit every winter for the last 10 years. i did injectors on my truck, pulled them and had them cleaned by marren in oxford, wasn't cheap. And I hate to go through the trouble not to have it solve the problem.
Subscribed as I have the EXACT same issue with my car. It was suggested for me to check my pushrods, so one weekend I'll check them out. Similarly, the car seems to have power just fine. Did you check your plug wires? I've seen guys with no codes for misfires replace their plug wires and it cleans up idle. Just brainstorming...
-J
-J
