I bought this 2003 Impala new. I loved my car and never had a problem with it. I had the oil changed regularly, and I had the radiator flushed and new hoses put on about a year before I had the first problem. I had just put new tires on it and a new battery. While driving one afternoon my temperature gauge went way over to the hot. Didn't make it to the orange, but came close. I put dexacool in the over flow bottle. I drove it again the next day and it did the same thing. Temp gauge would fluctuate between normal and hot. I parked it until I could get it into the Chevy dealer. I was told I had blown a head gasket and possibly cracked the head, and I needed a new engine, radiator, and hoses to the tune of $5000. I never had a light come on to say the car was hot, it didn't over flow from the radiator, just the gauge fluctuating. I decided not to spend that much for a repair on a 12 year old car with almost 108000 miles on it. Everything else on the car worked fine, the car looked great, but I sold it for $1200 to a young guy who thought he could do the repairs himself.

I am so disappointed, as I thought I could drive it for a few more years. When I Googled 2003 Impala repairs, I see it is a very common problem with this engine.

Bought this car in 2005 from the dealership. Bought the extended warranty in it but only lasted 24 months. A few months after the warranty expired the engine light came on. Took the car to the shop and they scanned it and a message appeared as "engine misfire, cylinder 6". At first I though it needed the spark plug and wire replacements but I did not change them. Later spent $206.00 from the "Bad"year tire shop where the auto technician stated that I needed to replace a fuel injector, which at the auto parts store costs a fraction. Finally, I found out that I had bad intake manifold gaskets. To sum up, I also had to replace the fan assembly. So what I ended Up Spending in the spring of '07 was $700.00. Three years later, in the Summer of '10, the same problem occurred plus a worn out valve spring. This time I ended up paying less since I did not to have to buy the fan assembly. My spending on this was $600.00 with parts and labor. I guess GM designed these cars to offer jobs to mechanics or to perform DIY fix ups, or simply to pay and arm and a leg at the dealership to get fixed. These cars may be a total junk, but as long as you do not intend to give payments of $400.00 or more a month on a new car, so far, with good maintenance, and the likely experience of the problem, you might be okay with having one like I do.

"Check Engine" light came on last week, it was overdue for standard maintenance anyway...the first thing found was brown sludge in the coolant (discovered before I signed the work order)...I asked the service manager if that was related to the CE light and was told it was possible but they wouldn't know for sure until they put it on the scope...about an hour later he called me at home and informed me that the intake manifold gasket was leaking oil into the cooling system and would need replacing...that was what caused the brown stuff in the coolant and the loss of vacuum pressure in that seal was what caused the CE light, so they were related...total cost of this visit was $1083 including the routine stuff and the SM threw in a few minor extras...my mom was without her car just overnight; had I taken it to them first thing in the morning he said I would've had it back that evening

Nov 25, 2009: Here is how I noticed the problem - The engine temperature gauge would rise as I drove the car - with heater on, even though engine was warm (and getting warmer fast!) no heat would flow. One day, a month or two ago, I noticed the temp getting very high - seemed a bit scary, but then before it got to the red zone, it dropped quickly. I figured - thermostat. Oh, and on the days when I was waiting for heat, there would be no heat until the engine temp started to drop - so, yeah, thermostat. Took the car in for an oil change today at a local chevy dealer and reported the problem. They just called and gave me the news about the gasket leaking, but emphasised that it WASN'T getting into the oil (where was it going???). Now I am hoping I am not getting a line of bull. It would be a real pisser if the engine dies soon, it has been making some unusual noises, but not bad enough to be concerned over - or so I thought until now, I am wondering if the oil hasn't been compromised. Should have the car back this afternoon.

Tomorrow, Thanksgiving, I do have many things to be thankful for, but this one will be in the back of my head, in the next year or two, will I be thankful for an honest service department? By the way, the service manager also assured me that GM has improved the gasket, so the replacement won't have this problem in the future. I am an "innocent until proven guilty" kind of guy - but will express due concern when I pick up the car.