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pretty bad
Typical Repair Cost:
Average Mileage:
117,167 miles
Total Complaints:
12 complaints

Most Common Solutions:

  1. drilled out & helicoiled, reinstalled (10 reports)
  2. replaced both heads (2 reports)
2003 Chevrolet Impala engine problems

engine problem

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2003 Chevrolet Impala Owner Comments

problem #12

Aug 012010

Impala 3.4L V6

  • Automatic transmission
  • 145,000 miles


I had the rocker arm bolt break off inside my engine twice. First repair was a heli-coil of cylinder 6 and 4. This cost $895. Then Cylinder 6 ripped out again; causing me to have to replace both heads on the engine at an additional cost of $1700.

- , Lansing, MI, US

problem #11

Nov 202012

Impala 3.4L V6

  • Automatic transmission
  • 250,131 miles

Driving down the highway in my high mileage Impala and something starts making a bunch of noise from the engine and power loss. It sounded like a little man with a hammer inside the engine. Got a tow home and parked it. Looked around for junkyard engine as I was guessing a connecting rod bearing failure. Started pulling off all the wiring, alternator and everything else to pull the engine. After pulling off the rear rocker cover, I discovered the #1 exhaust valve rocker bolt had stripped the alum threads out of the head. I'm a machinist by trade and I know about thread repair so I ordered a special time sert 8mm x 1.25 kit with 11.7mm long repair cores. the kit is # 1812CORE kit if you want to look it up on ebay. Get some extra time serts to do all the rest if you want to. Need 12 total for all rockers. Cost for kit $107 + $13 for extra serts. I had done an intake gasket replacement at about 125,000 miles and it was still holding. I'm trying to decide whether to go all the way down to the head gaskets as I have the brown sludge but no blowby in my coolant. This has been the best engine as far a wear I've ever owned. It does not burn a drop of oil between 15K oil changes. I would only recommend this job to someone who considers themselves a decent mechanic. Rate it a 6 or 7 on a 10 difficulty scale. Only because you don't have to pull the engine. I'm planing on using a right angle drive drill to do the time sert install on the rear bank. I'm hoping that with gaskets, seals, time serts, oil, coolant and such, I can have her back on the road for about $250-300

- , Central, TX, USA

problem #10

Jan 152011

Impala 3.4L V6

  • Automatic transmission
  • 82,021 miles

whats with this 3.4L V6 engine. again a rocker bolt pulled out threads (#3 exhaust valve). take apart again drill and helacoil(only took 2.5 hrs. this time). still wondering if damage was done back when intake gaskets were done under warranty. keeping my fingers crossed

- , Garson, Ontario, Canada

problem #9

Jan 292011

Impala 3.4L V6

  • Automatic transmission
  • 82,642 miles


here we go again third time is the charm got to love those 3.4L V6 engines. this time #1 ehxaust valve pulled out noticed both #5 cylinder valves seem loose also #1 intake push rod came trough rocker replaced rocker and push rod drilled out remaining rocker threads and helacoil lets hope this last longer than 2 weeks

- , Garson, Ontario, Canada

problem #8

Oct 092009

Impala 3.4L V6

  • Automatic transmission
  • 68,972 miles

2003 Impala with 3.4L rocker bolt pulled threads out of head on #1 cylinder(intake valve)

figured out how to take it apart but dropped push rod into intake must take it all apart

drilled and helacoil to fix nice weekend job

Intake gaskets were replaced under warranty by a GM dealership @ 56000 kms

wonder if rocker bolts over torqued then

- , Garson, Ontario, Canada

problem #7

Aug 162010

Impala 3.4L V6

  • Automatic transmission
  • 135,600 miles

My wife was driving home from work when suddenly the engine started missing and the check engine light came on. She managed to get it home. I checked for a loose spark plug wire but every thing was in tact. My meighbor who is a mechanic came over and after checking things he looked in the front valve cover through the oil cap and said there it is. You could see the lifter was loose and laying in there. Had it towed to his garage and he put helicoil in and bolted the valve back in place. Now I'm wondering how soon another one will go. Time to start looking for another car. Not GM.

- , Canonsburg, PA, US

problem #6

Aug 122009

Impala V6

  • Automatic transmission
  • 80,000 miles


I've had my car for 3 years, and when I first got it, I was satisfied. That is until last August when something started knocking, and when I took it to the mechanic that specializes in GM cars, they said it seemed to be a common problem, the rocker arm had ripped out of the head. They had to replace it with a bigger bolt so it wouldn't happen again, but warned me that once one goes, they all start to. It was $200 to get fixed and 10 months later, I've had to replace 4, this last time 2 went at the same time. Only other solution is to replace the head. Then the car started using oil like crazy, and the transmission started slipping. Was a good car until it hit the 100,000 mark, then it just started falling apart. Have seen a lot of good reviews for the chevy impala so I'm just wondering if I got a lemon. My dad swears by Chevy and won't buy anything else.

- , Hickory, NC, USA

problem #5

Dec 092009

Impala LS 3.8L V6

  • Automatic transmission
  • 145,000 miles

Bought this car for my daughter from a mechanic who had done all oil changes on the car and had originally purchased for a family member. Said he had already replaced water pump, intake manifold & gaskets. My daughter drove for about a month and engine light came on and motor was knocking. Shop quoted $2800 to have helicoil and remount 3 rocker arms that had pulled out of the motor. Was told the motor had probably overheated before, thus the intake manifold gasket problem. I sold the car for junk, taking a BIG loss. Research had shown this seems to be an inevitable problem with this GM motor that they don't car to fix. I have always been a GM lover, passed down from my Dad, but am truly disappointed and will shy away from GM cars from now on. This was the 2nd GM car I've had to deal with this same problem on.

- , Columbia, MO, USA

problem #4

Jan 102010

Impala 3.4L

  • Automatic transmission
  • 78,000 miles

short and sweet.. this will be the last Chevy product we will car will be a Nissan or far leaking intake manifold gasket.. and now studs ripping off the head for no apparent reason... what a piece of sh*t.. i have read lots of complaints about this impala after i bought i am does not want to recall faulty parts that they later find as defects.. i wish now that they would have gone out of business..but we can thank the bail out for that one.. they will never learn

- , Grand Prairie, TX, USA

problem #3

Jul 062009

Impala 3.2L

  • Automatic transmission
  • 134,000 miles

Had to have my car towed to dealership and was told they had never seen this problem before in a Chevrolet Impala. Rocker arm bolts ripped out of both heads. I saw this for myself and it created a large hole in the head. I saw other customers had their complaints listed so here's mine. The head number was 262 and I did file a complaint with GM but it was not under warranty so I am out a bundle. Dealership was very sorry but could do nothing but repair it. I was called every step of the way and was shown the damage before any repairs were done. But I NEED MY CAR so I had it fixed did not want any car payment in this economy.


problem #2

Feb 032009

Impala LS 3400

  • Automatic transmission
  • 99,000 miles

poor casting quality of an aluminum head, gm knows of the problem and say it is isolated to heads stamps with a casting id of 225. gee wiz thanks alot, that doesn't fix it gm it just says its a p.o.s. and nothing else. the helicoils seem to be holding but only time will tell

- , Florence, KY, USA

problem #1

Mar 132009

Impala 3.4L

  • Automatic transmission
  • 105,633 miles

Engine lost power, got very noisy, initially thought had lost a coil pack, but no, the rocker arm mounting bolts had ripped out of the head at cyl #1. The rest were all starting to do the same. All removed, drilled out and helicoiled. What an abysmal excuse for an engine. Way past warranty, GM denies all responsibility. Last GM I will ever own, and I've had them since 71. This vehicle, bought new, has been a disaster.

- , Ottawa, ON, Canada

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