: updated 10/25/2006 - everytime the vehicle was started and the engine was cold, it made a knocking noise, which continued until the engine warmed up. There were no warning signs prior to the incident. The vehicle was taken tot he service dealer who said the noise was carbon build-up on the piston. The dealer tried running cleaner into the engine twice but the noise was still there. The dealer said it was piston slap making the noise and that it was ok to drive.

- Manistee, MI, USA

The engine in my 2000 Chevy has a knock and tapping noise this has been a ongoing problem I have talked to two Chevy dealers and they say it is normal but it keeps getting worse the mileage now is 76585.

- Fletcher, NC, USA

2000 K3500 Silverado has had three failed fuel injector pumps, fuel transfer pump, automatic transmission at 70,000 miles and boost regulator failed. When the consumer removed the engine, to evaluate the damage, to see if it could be rebuilt, he discovered the second main bearing cap from the front of the engine was missing a bolt.

- Rio, WI, USA

General Motors 2000 Silverado truck-brake problems-owner financed repairs-rear brakes and timing belt ($1,800 dealer)-most recent front brakes-rusted rotors-retailer replaced ($200). Suspect defective materials manufactured by GM resulted in equipment failures. Dealer should be responsible to refund repair costs to consumer.

- Charleston, WV, USA

2000 Chevrolet Silverado developed problems with the brakes and the engine. The engine knocks when started due to piston play.

- Harlan, IA, USA

Engine was making a knocking sound while idling. The consumer was told by the dealer that GM was aware of the problem, however there was no fix. The dealer also stated the problem was due to a piston slap.

- Tomah, WI, USA

Engine knocks on startup...was told by the dealer it is normal...bull@#$#...we are hard working people who must depend on our vehicle to get us to work...I do not trust this truck very far from home. Fyi to all other owners...there is a class action pending on this problem. We didn't plan on paying this much for a vehicle just for it to sound like this. Other dealers are aware of this problem..so trading it off without loosing your shirt is impossible.

- Coleman, OK, USA

I own a 2000 5.3 vortex V8 in my Chevrolet and the engine makes horrible noise when its cold, referred to as slapping of the piston sleeve. What can be done about this if anything. Seems like an on going problem for many GM owners and something that is only resolved once a big stink is made of it before any possible action is done. I really love my truck but, this in conjuntion with the noise I get in cold weather going over speed bumps or unleveled surfaces in the shock or the frame. I had all kinds of parts replaced and it still comes back in cold weather, along with the knocking noise on cold starts. Any advise out there for a resolution? thanks nhall.

- Manassas, VA, USA

My 5.3 liter Silverado has a diesel like noise in the motor until it reaches normal running temperature, then it runs great. Its very loud the first 30 secs. From a cold start. My local GM garage said that is normal for a 4.8 and a 5.3 motor. They called it piston slapping, to me it is very abnormal. And will it get worse, I asked. They had no answer. They did comment that GM has not resolved this bulletin yet. I love my truck, I hope I get 200K miles out of it. Now I only have 50K. What's a person to do if the maker of his favorite auto can't come through with a resolution. It also affects resale value if I decide to sell.

- Mcdonald, OH, USA

While driving vehicle slams hard into gear. Engine check light either comes on before or after this occurs. Dealership serviced vehicle 4 times but the problem still exists.

- Sikeston, MO, USA

When starting vehicle the rod sounded like it was coming through the engine.

- Saginaw, MI, USA

Ongoing problem for rough idle, from the time the vehicle was purchased new. Several dealers told me it was normal, another said it was problem with the 5.3 liter; however, nothing to worry about. Fuel injectors have been cleaned several times. Now vehicle out of warranty. After vehicle is up to operating temperature and is shut off and remains for approximately half hour, upon restarting, vehicle "tumbles." I contacted Chevrolet customer service who provided me with an extended warranty on the engine and they have "washed there hands" of any other problems they may occur. My complaint is the rough idle has always been present, and now the "tumbling" is being caused as a result of the prior problem. This vehicle has been in service numerous times and the problem has not been diagnosed by Chevrolet. Do any service bulletins exist for a similar problem as this? file #1-89542103 & 1-89542103. Automatic transmission was another issue that was addressed while under warranty. Now, tcc valve is sticking causing a delayed gear engagement. Again, sorry but your vehicle is out of warranty.

- Cooper City, FL, USA

Consumer complained of defective engine making constant noise. Vehicle also vibrated while driving. In addition, dealer replaced water pump and engine belts.

- Rochester, NY, USA

There is a knock at start up and a constant ticking in the engine.

- Bryan, TX, USA

Consumer states that engine block and the piston are made out of two different kinds metal. So the heat expansion of the two are not compatible, causing engine cold cranking knock. This is a common problem.

- Robertsville, MO, USA

1st PCM broke at 19735 miles in wytheville virgina was able to limp to dealer they replaced the PCM and cam sensor. 2nd time at douglas ga. They replaced the PCM and crankshaft sensor.I pull a 5th wheel and the 2 nd time I had just put in to a camp site and was going to town when it quit in the camp road doing about 20 I had to call for a tow to Chevrolet dealer. Note both dealers were excellent. I was lucky I did not have the camper on. Is this a proublem with this truck?

- Ocala, FL, USA

Engine check light went on day after purchase. Saturday. Returned to dealer on Monday for checkup. Dealer said they couldn't reproduce the problem. Check engine light went on 08/10/2000. Returned to dealer. This time they checked the national computer and found that the knock sensors were overtorqued at the factory and replaced them. Why didn't they check the national computer when they had the truck the first time? started truck up in am 11/13-/2000 oil light came on. Checked oil, was full. Started truck up again, thought maybe guage was incorrect. Still no oil pressure. They towed truck in and replaced oil pump. The mileage was only 4513. I wanted engine replace, but they said there was no damage. Gas pedal sticking at 23550 miles. Returned truck to dealer. They installed new throttle body.also oil filler tube was not installed correctly. Oil was leaking from tube. They fixed this also.at 26581 miles engine started to have valve noise on cold startup. Returned to dealer. They said nothing was wrong. On 12/05/2001 returned truck due to tapping noise. This time they said it was due to castrol oil filter. They changed oil and put on PF59 filter. Thought problem was fixed. Engine still has lift noise on cold startup. Also complained of transmission double shifting. Dealer can't find anything wrong. This truck has been in the shop so many times they should extend the warranty to 10 years, but I know they are afraid to do that.

- New Cumberland, PA, USA

Within a month after our purchase, I took our truck to tony Chevrolet's service dept. For an engine knock. I was told this noise is normal to "all" 2000 Chevrolet and GMC trucks with the 5.3 liter engine. I asked how an engine knock can be normal to a brand new engine and was told that the noise was called "piston slap" which General Motors is aware of this "defect" and was working on a fix. I then explained to the service writer, since I've worked as a mechanic, that I've never heard a new or rebuilt engine knock unless there was a mistake made or a faulty part installed. I've heard high mileage engines with a knock problem, and I've heard high mileage engines with "piston slap". after research I found out GM was going to replace the faulty pistons with GM's new design pistons and that would take care of the "pistion slap" issue. After talking with another dealership about this issue, I was told that GM has replaced a few engines with the new designed pistions which now still have the "piston slap". I was shown bulletin # 01-06-01-028 which stated models:1999-2002 Chevrolet/GMC pickup & utility models,2002 Cadillac escalade (2wd) with 4.8L,5.3L or 6.0L engines may exhibit an engine knock noise that begins in the first 12,000-15,000 miles of use. The knock noise is most often noticed during start-up and typically disappears within the first 5-30 seconds (may last longer in extreme cold temperatures) since we live in Alaska this is very true. The noise is usually more noticeable on the intial start-up when the tempture is below 50 degrees and may be more pronounced on the first start following a long trip. The noise "may" be caused by an interaction between carbon that has formed on the piston, the piston motion and the cylinder wall. At this time, attempts to repair this condition by replacing the engine assembly or pistons is not recommended. Our truck's performance has gone down due to the knock sensor detecting this particular problem.

- Wasilla, AK, USA

Engine valves would make a loud tapping sound intermittently when starting. Dealer was notified, and informed consumer not to be concerned if it did not last more then a minute.

- Calvert, TX, USA

Engine knocks very badly at cold or hot start up. Knocking lasts for minutes. Chevrolet says they know about problem. States that the piston skirts are too short causing piston wobble. They also start they can't fix at this time. Engine sounds like a diesel at start up noise is so bad. I am nervous to take truck out of town for fear of engine failure.

- Phoenix, AZ, USA