You are here:

Chevrolet Repair/2004 impala ss rough/low idle

Advertisement


Question
I have a 2004 impala ss that when first started idles at about 500-800 rpm and a little rough and often dies out or wont start without stepping on the gas. i have replaced the aic on it as the code threw out used to be a high idle, now its the opposite. there is no code being thrown so i dont have that to go off of. just that it usually wont start without stepping on the gas and then idles low and rough for a few minutes then is fine. if you dont let it idle then the car dies out. this is happening more now that it is cold out. any help would be appreciated. oh yeah i did the regular tune up plugs wires air filter oil change

Answer
HI MIKE,,THIS IS JUST A GUESS WITH SO LITTLE TO GO ON, BUT TO ME THIS SOUNDS LIKE A COOLANT TEMP SENSOR IS BAD..IT MAY THINK THE ENGINE IS WARM AND NOT RAISING THE IDLE ENOUGH AND ALLOWING MORE FUEL TO ENTER THE ENGINE BECAUSE IT THINKS THE ENG IS WARM !!!THE ONLY WAY YOU WILL KNOW FOR SURE IS LET THE ENG COOL DOWN, PLUG YOUR SCAN TOOL IN AND CK THE DATA [NOT CODES]
BEFORE YOU START THIS THE COOLANT TEMP SENSOR SHOULD BE ABOUT THE SAME TEMP AS THE OUTSIDE AIR  OR MAYBE JUST A LITTLE WARMER..IF NOT THE SENSOR IS MORE THEN LIKELY BAD..I WILL ASSUME THAT AFTER THE ENG WARMS UP IT IS OK ??? YOU ALSO SAY THAT YOU REPLACED THE  AIC ?? YOU MEAN THE IAC [IDLE AIR CONTROLLER] ??? IF THE COOLANT TEMP SENSOR DOES NOT DO THE TRICK,CK THE BACK SIDE OF THE THROTTLE PLATE FOR ANY CARBON BUILD,IF SO,,, CLEAN IT WITH A CLEANER AND SOFT BRUSH..YOU WANT THIS CLEAN.DO NOT SCRATCH THIS PALTE..LET ME KNOW HOW YOU MAKE OUT..GOOD LUCK TO YOU,,,TOM..

Chevrolet Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


TOM SHEETS

Expertise

PLEASE READ ALL OF THIS BEFORE ASKING ANY QUESTIONS. IF THIS CHEVY SECTION IS MAXED OUT.YOU CAN REACH ME IN THE OLDS/BUICK SECTION. Will answer questions from 6:00am to 10:00pm all days [EST][[[ NO DIESEL OR PAINT QUESTIONS]]] will answer all 1965 to present QUESTIONS ON ALL GM'S on mechanics of these cars. Keep in mind i am not there in person i am going on what you are telling me !! PLEASE IF ASKING A QUESTION GIVE ME AS MUCH INFO AS POSSIBLE. THE MORE THE BETTER. SUCH AS YEAR,MAKE,MODEL,ENGINE SIZE. THIS WILL HELP ME HELP YOU. I will not be able to answer all questions because of some situations that i would really need to be there and see things for myself,such as electrical issues. In many cases i would need wiring diagrams. I can also give you an estimate on what the cost would be at our repair shop as an idea to help you. Keep in mind that my answer is ONLY MY ADVICE,ck with your mechanic as well.. >> THANK YOU, TOM..

Experience

I have been a ASE certified master mechanic for over 30 years and certified IN ALL 8 CATEGORIES,[engine repair,engine performance,auto trans,manual trans,clutches,steering and suspension,brakes,electrical systems,heating and air/cond. I am also a state CERTIFIED inspector for over 30 years. I do computer work [pcm]fault codes,pcm flashing,state inspection monitor readiness,repairs on exhaust,fuel service,[injection and carburetor,] charging system problems, running issues,alignments,frame problems,tire balance,struts and of course standard and anti-lock brakes.

Organizations
nys state auto repair industry and ase group.

Publications
N/A

Education/Credentials
high school,4 years of tech school,and many many hours of auto training with many gm classes and aftermarket training classes..

Awards and Honors
ASE MASTER TECH CERTIFIED IN ALL 8 CATEGORIES.NYS INSP LICENSE AND A/C CERTIFIED

Past/Present Clients
MANY CUSTOMERS IN OUR BUSY SHOP.

©2016 About.com. All rights reserved.