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Chevrolet Impala, Sedan
#1135 of 2014 Re: garypen [roderacer]
Mar 15, 2005 (4:50 pm)
I just came across this forum today---about 4 years too late judging by the date stamps. Anyway, I have a 2002 Chevy Impala LS. Like you and some others, I have this odd popping sound that occasionally, and annoyingly, seems to be coming from the dash. Like you, I thought a rock or pebble had hit the windshield, but when it happened a 3rd and 4th time I realized there was something else going on.
Recently I brought it to the dealer for some unrelated work, and I happened to mention the noise, but the service advisor stated that in all probability the dashboard would have to be taken apart, and that would be very expensive. I decided to wait on investigating what the problem might be, but as time grows on I am getting more and more concerned about what the problem might be. Note that there is no predicting when the problem will happen, but it does appear to be happening more and more.
I've tried to correlate the problem with the temperature, but it seem to occur when it is cold and relatively mild as well.
#1136 of 2014 Re: Check engine code P0140 [luvdaimpala]
Mar 15, 2005 (7:38 pm)
P0140 = HO2S Circuit Insufficient Activity Sensor 2
Sensor #2 is the one after the catalytic converter, used to monitor catalyst efficiency.
Here's the Readers' Digest version of the diagnostics. Any competent tech should be able to diagnose and correct it:
Document ID# 475350 2000 Chevrolet/Geo Impala
The PCM supplies a bias voltage of about 450 mV between the HO2S signal and low circuits. When measured with a 10 megaohm Digital Multimeter, this may display as low as 320 mV. The oxygen sensor varies the voltage within a range of about 1000 mV whenthe exhaust is rich, down through about 100 mV when exhaust is lean. The PCM constantly monitors theHO2S signal during Closed Loop operation and compensates for a rich or lean conditionby decreasing or increasing injector pulse widthas necessary. If the HO2S 2 voltage remains at or near the 450 mV bias for an extendedperiod of time, DTC P0140 will set.
Conditions for Running the DTC
• No TP sensor, EVAP system, misfire, IAT sensor, MAP sensor, Fuel Trim, fuel injector circuit, EGR Pintle Position, ECT sensor, CKP sensor, or MAF sensor DTCs present.
• Engine run time more than 200 seconds.
Conditions for Setting the DTC
HO2S 2 signal voltage remains between 425 mV and 475 mV for up to 90 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using a scan tool.
Check for the following conditions:
• Corroded exhaust flange bolts -- Using a Digital Multimeter, ensure that continuity exists between the engine block and the heated oxygen sensorshell. If resistance is excessively high, replace corroded exhaust flange attaching hardware as necessary. Refer to Exhaust System Replacement in Engine Exhaust.
• Poor connection or damaged harness -- Inspect the harness connectors for the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formedor damaged terminals
- Poor terminal to wire connection
- Damaged harness
• Malfunctioning HO2S heater or heater circuit -- With the ignition ON, and the engine OFF the HO2S voltage displayed on a scan tool should graduallydrop to below 250 mV or rise to above 600 mV. If not,disconnect the HO2S and connect a test lamp between the HO2Signitionfeed and heater ground circuits. If the test lamp doesnot illuminate, repairthe open ignition feed or sensor groundcircuit as necessary. If thetest lamp illuminates and the HO2Ssignal and low circuits areOK, replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement .
• Intermittent test -- With the ignition ON, monitor the HO2S signal voltage while moving the wiring harness and related connectors. If the malfunctionis induced, the HO2S signal voltage will change. This may help isolatethe location of the malfunction.
If the DTC cannot be duplicated and is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set. Also refer to Testing for Intermittent and Poor Connections in Wiring Systems.
Mar 16, 2005 (6:31 am)
2001 LS with 34000 miles. Front rotor on drivers side gets very hot while driving, compared to other rotors. Car also pulls to left when stopping quickly. Metalic grinding noise coming from wheel.
Changed calliper, but has not helped. Pads and rotor seem fine.
Any ideas as to what might be causing this problem?"
#1138 of 2014 Impala noise popping /1954 boomer
Mar 16, 2005 (6:49 am)
I believe that popping noise in the dash is common with most of the Impalas.....I have a 2001 LS and my son a 2003 LS we experience the same thing.....usually getting into the car when very cold and then driving and inside the car starts to warm up.....it appears to come from the dash or the front upper roof liner area........I wouldn't be concerned and certainly wouldn't spend the money to check it out......its probably to do with materials expanding and contracting that are brittle and pose no concern other then the annoying noise...good luck!
#1139 of 2014 Re: Impala noise popping /1954 boomer [charts2]
Mar 16, 2005 (4:53 pm)
I didn't expect to get a reply back so soon! Thank you very much for responding. It is comforting to know that I'm not the only one experiencing this problem, and that the problem doesn't appear to be anothing major.
#1140 of 2014 4 Years / 37,000 miles
Mar 17, 2005 (8:32 am)
My ("Our" actually, wife the drives to work, I walk) 2001 LS continues to be great!
I have upgraded to Sylvania Brite Lites - incredible difference in light!
Switched to Mobil 1 after after the first year. Have used nothing else, also use the larger Mobil 1 oil filter (One for the late '90's Blazer V-6) fits with no problems and works well!
Still have the original pads, rotors, and calipers. Never have had any problems. Vehicle is used in short distance stop and go traffic. Went to change the front pads. Still have more than half left. Brakes should start sqealing when 1/8" of pad is left. No unusual wear on the rotors. Boots look fine.
Change oil and air filter every 3 months
Change fuel and cabin filter every year
Change oil every 6 months
Replaced all four tires at 27,500 miles
Driver's side high beam wouldn't work
Fixed under warranty, pinched wire
On Star won't work
Haven't got it fixed yet
Excellant vehicle, runs well, handles well, warms up quickly in the winter (Wyoming).
#1141 of 2014 Jacking Points
Mar 17, 2005 (8:42 am)
Someone earlier asked about jack points.
Place jackstands where the tire jacks go. Use a floorjack on the ridge just inboard of the rocker panels. DON'T try to raise the vehicle other than the cutouts in the rocker panels. The rocker panels are plastic and you will bust the plastic fastners holding the panels to the car. $37 for a replacement set of fastners. Yes plastic - doesn't rust.
Anybody get leaves in the front fenders? Noticed the visible fiber piece (visible when you open the front door)sort of drifted down and stuff has collected at the bottom. Used a Shop Vac to suck out the accumulated debris.
Mar 17, 2005 (7:07 pm)
I purchased a used 2000 Impala LS six months ago. Had the first oil change two weeks ago. The oil change outlet put in 5W30 rather than the 10W30 recommended for the V-6 3800 engine. Manual states 5W30 is fine up to 60 degrees. Should this be corrected before summer or sooner?
#1143 of 2014 Impala tie rods replaced by dealer
Mar 18, 2005 (6:34 am)
hi. My 2001 impala LS , 39,500 mi, in exc cond., went to dealer & they required replacement of BOTH front tie rods. The left was way out of line, and the right was beyond specs. I was charged about $160 or so for this. There was no mention of any TSBs or recalls or voluntary fixes, etc ... tho I understand from this forum in a brief search that there may be an ISS (??? ) TSB ... tho I don't know what that is ... pertaining to the tie rods.
Can anyone give me any additional info on this, and on whether I should confront the dealer with this info... the work was done yesterday.
PS. The transmission was replaced at 37000 miles by dealer "voluntary warranty" after they had misdiagnosed problem 3 days earlier and charged me $250 for cleaning ignition fuel jet nozzles (whatever). While I"m pleased they fixed it, they didn't offer any refund of the $250.
Thanks for help!
#1144 of 2014 Re: Oil Weight [middleageguy]
Mar 18, 2005 (12:25 pm)
Depends on where you live, but if it were mine I'd probably rather pay an extra $20 and replace it before summer vs. taking a chance and possibly doing greater than $20 worth of damage. In theory the "5W" and "10W" refer to the viscosity of the oil in cold weather, and the "30" to warm weather, so both should act the same in the summer. Could be there's some quirk about 5W at startup in the summer (before the oil has heated up), I really don't know. I'd spend the $20 just for peace of mind (or maybe take it back to the quick lube place and have them correct the problem).