5.3l Pinging/detonation

Steve's05 · April 23, 2008

should a 2005 5.3l in a Z71 Crewcab have this issue with 87 octane unleaded gas? had it to the dealership and they ran upper engine cleaner through it and it did not help. bought the truck used with 40k it now has 42k and it will run fine on 91 octane. the dealer wants to charge me 95.00 to check programing. I think it was programed prior to me purchacing the truck. thoughts?

bossier62guy · April 23, 2008

should a 2005 5.3l in a Z71 Crewcab have this issue with 87 octane unleaded gas? had it to the dealership and they ran upper engine cleaner through it and it did not help. bought the truck used with 40k it now has 42k and it will run fine on 91 octane. the dealer wants to charge me 95.00 to check programing. I think it was programed prior to me purchacing the truck. thoughts?

Do you think someone had a performance tune or used a hand held tuner to install a performance tune to the truck? That could explain your problem if that was the case.

Steve's05 · April 23, 2008

should a 2005 5.3l in a Z71 Crewcab have this issue with 87 octane unleaded gas? had it to the dealership and they ran upper engine cleaner through it and it did not help. bought the truck used with 40k it now has 42k and it will run fine on 91 octane. the dealer wants to charge me 95.00 to check programing. I think it was programed prior to me purchacing the truck. thoughts?

Do you think someone had a performance tune or used a hand held tuner to install a performance tune to the truck? That could explain your problem if that was the case.

not sure, bought from a dealer

Steve's05 · April 24, 2008

No other help? The noise I am talking about isn’t like normal either. It doesn’t happen under acceleration, it happens mainly only when lugging the engine. Like after acceleration and you start to let up on the pedal to coast is when the noise occurs. I filled the tank with about 10gal of 91 octane today and the noise is mainly gone but still slight. Also on a side note the engine has a surge when in cruise control only and only when coasting down a hill. The engine idles smoothly and has great response under acceleration.

this is very confusing, any help would be appreciated.

Norseman · April 24, 2008

No other help? The noise I am talking about isn’t like normal either. It doesn’t happen under acceleration, it happens mainly only when lugging the engine. Like after acceleration and you start to let up on the pedal to coast is when the noise occurs. I filled the tank with about 10gal of 91 octane today and the noise is mainly gone but still slight. Also on a side note the engine has a surge when in cruise control only and only when coasting down a hill. The engine idles smoothly and has great response under acceleration.

this is very confusing, any help would be appreciated.

Could be bad knock sensor. Do you ever wash your engine?

Steve's05 · April 25, 2008

No other help? The noise I am talking about isn't like normal either. It doesn't happen under acceleration, it happens mainly only when lugging the engine. Like after acceleration and you start to let up on the pedal to coast is when the noise occurs. I filled the tank with about 10gal of 91 octane today and the noise is mainly gone but still slight. Also on a side note the engine has a surge when in cruise control only and only when coasting down a hill. The engine idles smoothly and has great response under acceleration.

this is very confusing, any help would be appreciated.

Could be bad knock sensor. Do you ever wash your engine?

havent washed the engine yet, have only had the truck about 2weeks.

C6Racer · May 1, 2008

My truck has a pinging problem when I'm at highway speeds going up a steep hill. Running 89 octane completely resolves the problem. Since you said running 91 helps the noise go away then a bad knock sensor may be the issue but, as the dealer said, something wrong with the programming may very well have something to do with it. $95 is about the average price for that check anywhere. See if you can look up some specs on knock sensor resistance readings and have it checked out. Hope this helps and good luck!

C & A s Dad · May 2, 2008

Steve, I am sure GM's upper cyl cleaner is good but I would suggest you run at least one bottle of Chevron's Techron (# 65740) through it at the rate of 1 oz per gallon. If the ping does not go away it is most certainly not a carbon issue in the combustion chamber. I would then tend to believe you have a knock sensor issue as Norseman said or the truck has been tuned.

Steve's05 · May 3, 2008

Steve, I am sure GM's upper cyl cleaner is good but I would suggest you run at least one bottle of Chevron's Techron (# 65740) through it at the rate of 1 oz per gallon. If the ping does not go away it is most certainly not a carbon issue in the combustion chamber. I would then tend to believe you have a knock sensor issue as Norseman said or the truck has been tuned.

I added some ocatane booster/cleaner. it didnt help either. but I drove the truck from kansas to texas this past weekend and noticed that it didnt ping most of the way there or back. it started pinging again once I got back into Kansas City area, it was in the low 50 deg and coming out of texas/oklahoma it was in the 80deg range. wonder if it has something to do with temps. it does it a lot worse when temp is below 60 deg.

C & A s Dad · May 7, 2008

Steve, I am not sure what you added but I can tell you most of the injector/combustion chamber cleaners on the market are made to sell and not use. There are a few really good ones out there that produce results. They will not cure a bad knock sensor but if your issue is from carbon build up, I can promise you two tanks of fuel run with Techron at 1 oz per gallon will cure your issue. If this does not stop the ping, you have other issues. The 20 oz bottle of Techron is part # 65740.

MMM and Gumout also offer an "top shelf" cleaner that is a great product, I just do not have the part #s with me. It is my understaning they buy the main ingredient from Chevron. They will be priced around $10.00 or so for a 20 oz bottle. Use the Chevron if you can find it.

Steve's05 · May 8, 2008

well the pinging noise is getting worse. no matter what octane now. I am taking it back to the dealer tomorrow and let them check it out again.

C6Racer · May 8, 2008

Well, my pinging was getting worse by the day but, today I used Sea Foam and now it's like it never even had a problem. The only way to add it is through a vacuum line while the engine is running (I chose the brake booster line; somebody needs to be inside with their foot on the throttle to keep the engine from stalling) which will cause the MIL (malfunction indicator lamp) to turn on. Luckily, I had access to an OBD II scanner to turn it off with because shops can charge a lot to simply check for codes.

Sea Foam should be available at your local auto zone.

Steve's05 · May 9, 2008

Well, my pinging was getting worse by the day but, today I used Sea Foam and now it's like it never even had a problem. The only way to add it is through a vacuum line while the engine is running (I chose the brake booster line; somebody needs to be inside with their foot on the throttle to keep the engine from stalling) which will cause the MIL (malfunction indicator lamp) to turn on. Luckily, I had access to an OBD II scanner to turn it off with because shops can charge a lot to simply check for codes.
Sea Foam should be available at your local auto zone.

well the dealer is at a loss. they say that with no codes and all sensors working, that they dont know what to do. the test drove it for over 60 miles. and can hear the problem. they say that they are not sure its even engine noise, because it wont ping under acceleration. they are worthless. going to take to another dealership tomorrow.

redvett · May 9, 2008

Well, my pinging was getting worse by the day but, today I used Sea Foam and now it's like it never even had a problem. The only way to add it is through a vacuum line while the engine is running (I chose the brake booster line; somebody needs to be inside with their foot on the throttle to keep the engine from stalling) which will cause the MIL (malfunction indicator lamp) to turn on. Luckily, I had access to an OBD II scanner to turn it off with because shops can charge a lot to simply check for codes.
Sea Foam should be available at your local auto zone.

well the dealer is at a loss. they say that with no codes and all sensors working, that they dont know what to do. the test drove it for over 60 miles. and can hear the problem. they say that they are not sure its even engine noise, because it wont ping under acceleration. they are worthless. going to take to another dealership tomorrow.

Did the tech drive truck with a Tech2 hooked up? He should have been watching knock counts % timing.

C & A s Dad · May 9, 2008

Steve,

If you do not have a knock sensor issue I would suggest again the Techron. Seafoam is a wonderful product as well and will clean the combusiton chamber if injested through a vacum line. The only problem in doing this is it will take the path of least resistance meaning it will really clean the intake valves and cylinders closest to the vacume inlet and the other cylinders will not receive a lot of the chemical. It can also be injested through the throttle body with but that is another subject.

Find a dealer willing to use the tech 2 or at least try the Techron.