nocking/ ping Engine

[JustaGuy21]

i have a 2001 chevy 2500 hd 4x4 with 46k. goin up hills and when i am hard on the gas the engine will rattle and ping. i am told this is bad gas so i have ran the tank empty and put in new gas with fuel filter. It is still doin it. any suggestions??

[C & A s Dad]

One of two things. You either have a Knock sensor not working or you have enough carbon build it up in the Combustion Chamber that it is causing predetonation. The second it likely the casue especially if you have been using what I call "no name gas". I would try to fill it with Chevron if you have it avail and also add Techron at the rate of 1 oz per gallon. You may need to do this for two tanks. If it is carbon, the Techron will likely cure or at least help your problem. If not, you will need to check the knock sensor and/or get a Tech to clean your combustion chambers with a professional machine and chemical. IMO, Motorvac is the best but BG s is also a good system.

[skills4lou]

Here's the easier solution (and it says this in the owners manual):

Use higher octane gas. It's the low octane gas, not necessarily "bad" gas. Brand has nothing to do with it. My guess is you fill up with the cheapest gas at the pump, and it's not a high enough octane for your engine.

If I'm wrong all it's cost you is an extra $1-2 for the higher octane gas, but I'll bet you dollars to donuts I'm right.

[C & A s Dad]

Greg, I cannot speak for the octane requirements of a 6.0L 2500 series but for the 5.3L it requires only 87 and will not ping if all is well with the engine and knock sensor. It may run better and have more power with 89 or 93 but if the everything is working correctly, it does not require this higher octane fuel to eliminate pinging. Again, I cannot speak for the 6.0L as it may require (owners' manual) 93 octane. There is much debate on running 93 oct in the 5.3L. Many say it will generate more power and MPG, I use it in mine because I tow with it and it does seem to make it pull better in the hills. However, my 5.3L never pinged when I was using 87 oct.

 

This pinging is very common and we see it often with consumers who come into our stores. The car or truck ran great on 87 when new. They have used lower quality fuels and the carbon has now built up after 20,000 miles or more. Now it is pinging on 87 octane. They move up to 89 or 93 and it quits pinging. This is normally a direct result of carbon build up which makes the engine require higher octane fuels to keep it from pinging.

 

I will also respectfully disagree with you concerning the brands of fuels and their quality and/or performance. There was a recent article in Car and Driver where they had tested fuels and found that the "no name" fuel typically did not meet the posted octane ratings. The most critical piece to me concerning "no name" fuels is they meet only the minimum detergent requirements and do not contain the same quality detergents that fuels such as Chevron, Texaco, BP, Shell Etc.

 

I am curious as to your forum name. Are you involved with the LA VICA (Vocational Industrial Clubs of America) Skills program in anyway?

[skills4lou]

C&A's dad: I agree, 87 is usually all it takes. However, where I live the cheap gas at the pump is only rated 85. We can't even find 93 octane, our choices are 85/87/91. I am a firm believer in starting out with the easiest and cheapest fix. Spending another few dollars on higher grade gas is about the easiest "fix" I know. If flex06 can fix the problem by using the correct fuel then I believe that is the best solution.

I don't know for sure what the octane requirements are for the 6.0 either. My owner's manual (98 454) lists 87, and I have no pinging on 85. I do use 87 if I'm towing or hauling, but for just around town 85 does fine for me. The 6.0 may need the 91 due to higher compression ratio.

As for carbon buildup, here's MY experience: last three vehicles, all rated to burn 87, still running just fine with NO pinging at over 150,000 miles. My statements about brand name gas come from being friends with some bulk fuel delivery drivers. They deliver the fuel to Flying J, Conoco, Texaco, Exxon and some of the no name places. ALL the fuel comes from the same supply and goes through the same trucks. The only difference is the storage tanks at each individual gas station.

In my experience it's far more important to buy from a place that deals in larger quantities than what brand name it is. Perhaps we can agree in that buying from one of the big companies will probably get you better quality fuel. Why it's better doesn't matter, in the end if the engine runs good and doesn't ping under load then all is good.

 

My handle is the result of my wife (Louise) being happy she married a man with skills. I use my skills for her -> skills4lou