2003 Chevrolet Impala Problems

What owners report

Owners of this model year most often describe no-start or intermittent-stall conditions tied to the ignition switch and the factory anti-theft (Passlock) system, along with headlights and turn signals that stop working or flash on their own. A second common theme is coolant loss and overheating traced by mechanics to intake manifold and heater core leaks, often noticed as a sweet smell or a puddle. Many of these reports come in at higher mileage, though the security-related no-starts also show up on lower-mileage cars.

1. 1
   Electrical system

   Car will not start or stalls (Passlock / ignition)

   • 276 complaints (40%)
   • median 98,370 mi at 9.6 yrs old (210 state mileage)
   • 11 mention a crash, fire or injury
   • owner-quoted repair $687 (median of 24 quotes)
   • filed 2003–2024

   Owners describe turning the key and getting nothing, or cranking with no start, sometimes with the security light lit or flashing; waiting 10 to 20 minutes often allows a restart. Others report the engine quitting while driving or at a stop, with instrument panel lights flickering or gauges moving. Complaints mention the dealer diagnosing the ignition switch, key cylinder or body control module and, in several cases, the problem returning after a recall repair or a paid repair. Reported from roughly 47,000 to 200,000 miles, at all times of year; some owners note it happening more in hot weather or after rain.

   Recall 14V4000002 related service bulletins

   What to check: Ask whether recall 14V400000 was performed and whether the ignition switch, key cylinder or body control module has been replaced since. Try several cold and warm restarts during a test drive, and watch for the security light.

   2 excerpts from owner complaints in NHTSA records

   “My 03 Impala some times won't start. I have already got it fixed from dealer and as soon as it ran out of warranty, it started to have the same problem, which was fixed 6 months earlier by the dealer. Gm won't help and I am stuck some times, with the car being left about two to three times in shopping malls. Need some help from GM.”

   NHTSA complaint #10365540, filed 2010-11, 47,000 miles

   “Went to work early one morning, when I got off work got in car, put key in ignition and ignition would not turn. Had not had any previous problems with ignition at all. I tried other spare keys and they also would not turn ignition. A mechanic say that it is the ignition cylinder is froze.”

   NHTSA complaint #10217428, filed 2008-02, 75,551 miles
2. 2
   Exterior lighting

   Headlights and turn signals quit or flash

   • 100 complaints (14%)
   • median 75,023 mi at 6.2 yrs old (78 state mileage)
   • 1 mention a crash, fire or injury
   • owner-quoted repair $600 (median of 11 quotes)
   • filed 2003–2024

   Complaints describe low beams or all exterior lights going dark while driving, sometimes after switching to high beams, with the lights coming back only after cycling the switch repeatedly. Others report turn signals or hazards that light but do not flash, and some describe lights blinking on and off with the car parked or moving. Owners say dealers replaced the multi-function/dimmer switch or turn signal module, and in some cases could not diagnose the failure. Mostly reported between about 30,000 and 110,000 miles, often at night or in rain and snow when lights are in use.

   2 related service bulletins

   What to check: During a test drive, cycle low beams, high beams, turn signals and hazards several times and confirm the lights stay on. Ask whether the multi-function switch has been replaced.

   2 excerpts from owner complaints in NHTSA records

   “My 03 chevy Impala lights flash on and off all day long whether the car is on, off, or driving down the road I have gone to the dealer and they don't know what's wrong with it but they are willing to charge me $800 to try to fix it. Also the car does not start after it has rained.”

   NHTSA complaint #10251813, filed 2008-12, 50,200 miles

   “My high beam switch doesn't work in my Impala. My car is either an 02 or 03 and, after looking this up online, im seeing that there are a ton of other complaints. This is very obviously an engineering or negligence issue with the company. When driving at night, on occasion, if I switch my low/high beams, the lights may or may not go completely out. I have to switch them on and off again, maybe a few times, to get them to come back on. This poses a serious safety hazard since it could take a few seconds to get them to come back on.”

   NHTSA complaint #10348148, filed 2010-08, 32,000 miles
3. 3
   Engine cooling

   Coolant loss, overheating and intake manifold leaks

   • 37 complaints (5%)
   • median 68,050 mi at 5.0 yrs old (30 state mileage)
   • 2 mention a crash, fire or injury
   • owner-quoted repair $1,000 (median of 13 quotes)
   • filed 2003–2015

   Owners report a sweet antifreeze smell, low coolant, rising temperature gauges and sometimes a puddle near the front passenger side. Mechanics quoted in the complaints identified intake manifold gasket leaks or a failed heater core, and some owners link the damage to long-term use of the factory coolant. Dealers and shops replaced intake manifold gaskets and heater cores in several cases. Reported from about 15,000 to 70,000 miles and again at higher mileage; several owners noticed it in cold weather when the heater stopped working.

   2 related service bulletins

   What to check: Check the coolant level and look for residue or a sweet smell around the intake manifold and under the passenger-side carpet; ask whether the intake gaskets or heater core have been replaced.

   2 excerpts from owner complaints in NHTSA records

   “During an inspection of my 2003 Impala, mechanic advised of a coolant leak in upper intake manifold (a very common defect for this model / year) and it would cost hundreds of dollars to repair. Needless to say, I did not have the funds to repair it and all cars of this model / year should be recalled for repair.”

   NHTSA complaint #10336598, filed 2010-06, 60,000 miles

   “The car starting smelling like anti-freeze and then a big puddle appeared in the front passenger side of the car. The only thing we did was drive from nampa, id to billings, mt, which we have done four times before. It has been determined that the heater core needs to be replaced. The car has 68,000 miles on it right now as of july 28th, 2006. In novemeber of 2003, three months after I bought the car, the heater core was replaced at 31,000 by the lithia dealership in helena, mt. …”

   NHTSA complaint #10163746, filed 2006-07, 68,000 miles
4. 4
   Electrical system

   Speedometer and gauge failures

   • 38 complaints (5%)
   • median 98,370 mi at 8.8 yrs old (32 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2004–2019

   Owners report the speedometer quitting or working intermittently, with the instrument cluster needles moving erratically or other gauges acting up. Several say the dealer quoted several hundred dollars for cluster or module repair, and some describe the problem appearing soon after purchase. Reported from about 60,000 to 141,000 miles, with no clear seasonal pattern.

   2 related service bulletins

   What to check: Watch the speedometer and other gauges during the test drive, including over bumps, and ask whether the instrument cluster has been repaired or replaced.

   2 excerpts from owner complaints in NHTSA records

   “We bought my son a 2003 chevy Impala, the speedometer has quit functioning all of the sudden. Sometimes it works and sometimes it does not. He drives over two hours back and forth to college and I feel it is quite a safety issue and chevy will do nothing about it. I have read many complaints from people with the same issue and feel this should be a recall! I don't have $500.00 for the repair which many other people have had to pay!”

   NHTSA complaint #10243029, filed 2008-09, 65,000 miles

   “My security light started to flash then everything went crazy from there lights blinking on and off doors locking and unlocking then the radio will show locked on it trunk will open while driving down the road. The vehicle would start on cool days now that it has turned hot it will not start at all. …”

   NHTSA complaint #10234820, filed 2008-07, 100,003 miles

Buying note. A pre-purchase inspection that includes a cold and warm restart, a scan for stored body and ABS codes, and a check of coolant level and for leaks will tell you the most about this model year. Ask for records showing whether the ignition recall 14V400000 was completed, since several complaints involve no-start conditions that persisted afterward.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.